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1

ARRAYS OF BOTTLES OF PLUTONIUM NITRATE SOLUTION  

SciTech Connect

In October and November of 1981 thirteen approaches-to-critical were performed on a remote split table machine (RSTM) in the Critical Mass Laboratory of Pacific Northwest Laboratory (PNL) in Richland, Washington using planar arrays of polyethylene bottles filled with plutonium (Pu) nitrate solution. Arrays of up to sixteen bottles were used to measure the critical number of bottles and critical array spacing with a tight fitting Plexiglas® reflector on all sides of the arrays except the top. Some experiments used Plexiglas shells fitted around each bottles to determine the effect of moderation on criticality. Each bottle contained approximately 2.4 L of Pu(NO3)4 solution with a Pu content of 105 g Pu/L and a free acid molarity H+ of 5.1. The plutonium was of low 240Pu (2.9 wt.%) content. These experiments were sponsored by Rockwell Hanford Operations because of the lack of experimental data on the criticality of arrays of bottles of Pu solution such as might be found in storage and handling at the Purex Facility at Hanford. The results of these experiments were used “to provide benchmark data to validate calculational codes used in criticality safety assessments of [the] plant configurations” (Ref. 1). Data for this evaluation were collected from the published report (Ref. 1), the approach to critical logbook, the experimenter’s logbook, and communication with the primary experimenter, B. Michael Durst. Of the 13 experiments preformed 10 were evaluated. One of the experiments was not evaluated because it had been thrown out by the experimenter, one was not evaluated because it was a repeat of another experiment and the third was not evaluated because it reported the critical number of bottles as being greater than 25. Seven of the thirteen evaluated experiments were determined to be acceptable benchmark experiments. A similar experiment using uranyl nitrate was benchmarked as U233-SOL-THERM-014.

Margaret A. Marshall

2012-09-01

2

Benchmark Evaluation of Plutonium Nitrate Solution Arrays  

SciTech Connect

In October and November of 1981 thirteen approach-to-critical experiments were performed on a remote split table machine (RSTM) in the Critical Mass Laboratory of Pacific Northwest Laboratory (PNL) in Richland, Washington, using planar arrays of polyethylene bottles filled with plutonium (Pu) nitrate solution. Arrays of up to sixteen bottles were used to measure the critical number of bottles and critical array spacing with a tight fitting Plexiglas{reg_sign} reflector on all sides of the arrays except the top. Some experiments used Plexiglas shells fitted around each bottles to determine the effect of moderation on criticality. Each bottle contained approximately 2.4 L of Pu(NO3)4 solution with a Pu content of 105 g Pu/L and a free acid molarity H+ of 5.1. The plutonium was of low 240Pu (2.9 wt.%) content. These experiments were performed to fill a gap in experimental data regarding criticality limits for storing and handling arrays of Pu solution in reprocessing facilities. Of the thirteen approach-to-critical experiments eleven resulted in extrapolations to critical configurations. Four of the approaches were extrapolated to the critical number of bottles; these were not evaluated further due to the large uncertainty associated with the modeling of a fraction of a bottle. The remaining seven approaches were extrapolated to critical array spacing of 3-4 and 4-4 arrays; these seven critical configurations were evaluation for inclusion as acceptable benchmark experiments in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbook. Detailed and simple models of these configurations were created and the associated bias of these simplifications was determined to range from 0.00116 and 0.00162 {+-} 0.00006 ?keff. Monte Carlo analysis of all models was completed using MCNP5 with ENDF/BVII.0 neutron cross section libraries. A thorough uncertainty analysis of all critical, geometric, and material parameters was performed using parameter perturbation methods. It was found that uncertainty in the impurities in the polyethylene bottles, reflector position, bottle outer diameter, and critical array spacing had the largest effect. The total uncertainty ranged from 0.00651 to 0.00920 ?keff. Evaluation methods and results will be presented and discussed in greater detail in the full paper.

M. A. Marshall; J. D. Bess

2011-09-01

3

Exclusion of Nitrate from Frozen Aqueous Solutions  

NASA Astrophysics Data System (ADS)

Reactions occurring at the surface of ice, sea ice, and snow in Earth's cryosphere have an impact on the composition of the overlying atmosphere. In order to elucidate reaction mechanisms and model their contributions to atmospheric processes, the morphology of frozen aqueous surfaces and amounts of reactants contained therein must be determined. To this end, the exclusion of nitrate ions to the surface of frozen aqueous solutions has been studied by attenuated total reflection infrared spectroscopy (ATR-IR). In this technique the near-surface region of the frozen films are interrogated to a depth of a few hundred nanometers from the film-crystal interface. Aqueous solutions (0.001 to 0.01 M) of sodium nitrate (NaNO3), magnesium nitrate (Mg(NO3)2), and nitric acid (HNO3) were quickly frozen on the germanium ATR crystal and observed at a constant temperature of about -18°C. In addition to ice and the solutes, liquid water in varying amounts was observed in the spectra. The amount of nitrate in the surface liquid is three to four orders of magnitude higher than in the unfrozen solution. While all the nitrate salts exhibit exclusion to the unfrozen surface, the dynamics are different for different counter-ions. Results are compared to freezing point depression data and the predictions of equilibrium thermodynamics.

Marrocco, H. A.; Michelsen, R. R.

2013-12-01

4

Purification of aqueous plutonium chloride solutions via precipitation and washing.  

SciTech Connect

Pyrochemical operations at Los Alamos Plutonium Facility (TA-55) use high temperature melt s of calcium chloride for the reduction of plutonium oxide to plutonium metal and hi gh temperature combined melts of sodium chloride and potassium chloride mixtures for the electrorefining purification of plutonium metal . The remaining plutonium and americium are recovered from thes e salts by dissolution in concentrated hydrochloric acid followed by either solvent extraction or io n exchange for isolation and ultimately converted to oxide after precipitation with oxalic acid . Figur e 1 illustrates the current aqueous chloride flow sheet used for plutonium processing at TA-55 .

Stroud, M. A. (Mary Ann); Salazar, R. R. (Richard R.); Abney, Kent David; Bluhm, E. A. (Elizabeth A.); Danis, J. A. (Janet A.)

2003-01-01

5

Catalyzed reduction of nitrate in aqueous solutions.  

National Technical Information Service (NTIS)

Sodium nitrate and other nitrate salts in wastes is a major source of difficulty for permanent disposal. Reduction of nitrate using aluminum metal has been demonstrated, but NH(sub 3), hydrazine, or organic compounds containing oxygen would be advantageou...

P. A. Haas

1994-01-01

6

Plutonium Partitioning in the Purex Process with Hydrazine-Stabilized Hydroxylamine Nitrate.  

National Technical Information Service (NTIS)

The use of hydrazine-stabilized hydroxylamine nitrate (HAN) to partition plutonium from uranium in the Purex process was successfully demonstrated in a laboratory multistage contactor. Reduction rate constants for the HAN-Pu(IV) reaction were obtained and...

G. L. Richardson J. L. Swanson

1975-01-01

7

Redox reactions of neptunium and plutonium in alkaline aqueous solutions upon gamma radiolysis  

NASA Astrophysics Data System (ADS)

The paper is a brief review of data obtained by the authors from the study on redox reactions of neptunium and plutonium ions upon ?-radiolysis of their aerated alkaline aqueous solutions. It includes the information on radiolytic reduction of Np(V), Np(VI), and Pu(VI) ions under various experimental conditions. It was found that the values of Np(VI) and Pu(VI) reduction yields do not depend on alkali concentration. The values considerably increase in the presence of some organic compounds (EDTA and formate were investigated). The formation of the Np(V) peroxo complex was observed in the ?-radiolysis of alkaline aqueous solutions of Np(VI) and Np(V) in the presence of nitrate. The mechanism of radiolytic redox reactions of the ions is discussed in some detail.

Pikaev, A. K.; Gogolev, A. V.; Shilov, V. P.

1999-10-01

8

Silver Nanoparticles from Ultrasonic Spray Pyrolysis of Aqueous Silver Nitrate  

Microsoft Academic Search

Silver particles less than 20 nm in diameter were synthesized by pyrolysis of an ultrasonically atomized spray of highly dilute aqueous silver nitrate solution at temperatures above 650°C and below the melting point of silver. Feed solution concentration and ultrasound power applied to the atomizer were found to have a significant impact on the particle size of the silver nanoparticles.

Kalyana C. Pingali; David A. Rockstraw; Shuguang Deng

2005-01-01

9

Dried plutonium nitrate decontamination using HNO{sub 3} or Freon 113  

SciTech Connect

A request was made of the Separations Technology Laboratory to perform tests to determine the relative effectiveness of Freon 113 and 18% (3.15M) nitric acid on removing dried plutonium nitrate from Hypalon{reg_sign} gloves destined for use in F B-Line. Freon 113 was very inefficient for removing dried plutonium nitrate under conditions of moderate agitation of the liquid in contact with the dried compound. Nitric acid proved to be an excellent agent for decontaminating purposes for both the gloves and for the Pyrex glass. In tests conducted on the glass or on the gloves on which dried plutonium nitrate had not been removed by Freon 113, followup with nitric acid efficiently removed the residual plutonium nitrate. Tests were also conducted to give some measure of the resistance of the Hypalon glove to continuous contact with 18% HNO{sub 3} or with Freon 113. Following two weeks` immersion, there was little physical difference noted from the starting material, except the glove piece immersed in the Freon underwent an 8% weight gain.

Holcomb, H.P.

1988-02-04

10

Chemical treatment of plutonium with hydrogen peroxide before nitrate anion exchange processing. [Reduction to (IV)  

SciTech Connect

The major aqueous process used to recover and purify plutonium at the Los Alamos Plutonium Facility is anion exchange in nitric acid. This process is highly selective for plutonium; however, all plutonium must be as Pu(IV) to form the strongly sorbed anionic nitrato complex. The previous ''full-reduction treatment'' used at Los Alamos to obtain Pu(IV) results in a three- to fourfold increase in the feed solution volume and the introduction of kilogram quantities of extraneous salts immediately before a process whose function is to remove such impurities. That treatment has been successfully replaced by a single reagent, hydrogen peroxide, which converts all plutonium to Pu(IV), minimally increases the feed volume, and introduces no residual impurities. Safety aspects of this revised chemical treatment are addressed.

Marsh, S.F.; Gallegos, T.D.

1987-05-01

11

Ambiguous and forbidden parameter combinations for aqueous plutonium  

SciTech Connect

The concepts of forbidden and ambiguous oxidation-state distributions for plutonium are easier to understand when presented graphically. This note describes two diagrams that illustrate the phenomena.

Silver, Gary L [Los Alamos National Laboratory

2008-01-01

12

Plutonium silicate alteration phases produced by aqueous corrosion of borosilicate glass.  

SciTech Connect

Borosilicate glasses loaded with {approx}10 wt % plutonium were found to produce plutonium-silicate alteration phases upon aqueous corrosion under a range of conditions. The phases observed were generally rich in lanthanide (Ln) elements and were related to the lanthanide orthosilicate phases of the monoclinic Ln{sub 2}SiO{sub 5} type. The composition of the phases was variable regarding [Ln]/[Pu] ratio, depending upon type of corrosion test and on the location within the alteration layer. The formation of these phases likely has implications for the incorporation of plutonium into silicate alteration phases during corrosion of titanate ceramics, high-level waste glasses, and spent nuclear fuel.

Fortner, J. A.; Mertz, C. J.; Bakel, A. J.; Finch, R. J.; Chamerlain, D. B.

1999-11-22

13

Extraction of cerium-group lanthanide (III) nitrates from concentrated aqueous salt solutions by tributyl phosphate  

SciTech Connect

The extraction equilibrium for a hypothetical standard, designated as 1 M aqueous solution of Ln(III) nitrate and the state of the pure components in organic phase with a mole fraction of 1 have been determined assuming formation of tri- and tetrasolvates of the metal(III) nitrates in organic phase. The excessive thermodynamic functions of mixing tri-n-butyl phosphate with solutions of Ln(III) nitrate trisolvates are presented.

Pyartman, A.K.; Kopyrin, A.A.; Puzikov, E.A.

1995-01-01

14

High-speed impact test of an air-transportable plutonium nitrate shipping container  

SciTech Connect

To obtain information on package response for comparison with other test environments, a high-speed impact test was performed on a modified Federal Republic of Germany 18B plutonium nitrate air-transportable container. The container, modified with reinforcing rings for improved crush resistance around the inner tube assembly, was impacted at a velocity of 137 m/s onto an unyielding surface. Substantial crushing of the foam overpack and extensive deformation of the container cavity occurred, causing release of the liquid surrogate contents from the titanium shipping container. The container damage resulting from the high-speed pulldown test was more severe than that from a 185-m free fall onto a semirigid surface by a similar container or the crush environment produced by a 9-m drop of a 2-Mg block onto the container resting on an unyielding surface.

Yoshimura, H.R.; Pope, R.B.; Leisher, W.B.; Joseph, B.J.

1980-04-01

15

Potentiometric Determination of Free Nitric-Acid in Trilaurylamine Solutions Containing Plutonium Nitrate (Dosage Potentiometrique de L 'Acidite Nitrique Libre Dans les Solutions Organiques de Trilaurylamine).  

National Technical Information Service (NTIS)

A potentiometric method of determination of the free nitric acid in trilaurylamine solutions containing plutonium or thorium nitrates is described. The potentiometric titration is carried out in a mixtrue of benzene and 1, 2-dichloro ethane with a standar...

J. J. Perez J. C. Saey

1965-01-01

16

Method of separating thorium from plutonium  

DOEpatents

A method of chemically separating plutonium from thorium. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

Clifton, David G. (Los Alamos, NM) [Los Alamos, NM; Blum, Thomas W. (Los Alamos, NM) [Los Alamos, NM

1984-01-01

17

Method of separating thorium from plutonium  

DOEpatents

A method is described for chemically separating plutonium from thorium. Plutonium and thorium to be separated are dissolved in an aqueous feed solution, preferably as the nitrate salts. The feed solution is acidified and sodium nitrite is added to the solution to adjust the valence of the plutonium to the +4 state. A chloride salt, preferably sodium chloride, is then added to the solution to induce formation of an anionic plutonium chloride complex. The anionic plutonium chloride complex and the thorium in solution are then separated by ion exchange on a strong base anion exchange column.

Clifton, D.G.; Blum, T.W.

1984-07-10

18

Recovery of plutonium from phosphate containing aqueous analytical waste solutions using macroporous anion exchange resin  

Microsoft Academic Search

Distribution ratios of Pu(IV) between 7.5M HNO3+0.75M H3PO4+0.3M H2SO4 media and a macroporous anion-exchange resin Amberlyst A-26 (MP) increased from 40 to 250 when 1M aluminium nitrate was added to the aqueous medium. When 1M ferric nitrate was used in place of aluminium nitrate the distribution ratio further increased to 850. The 10% Pu(IV) breakthrough capacities with a 5 ml

I. C. Pius; M. M. Charyulu; C. K. Sivaramakrishnan; S. K. Patil

1994-01-01

19

Reductive catalysis of novel TiO 2\\/Fe 0 composite under UV irradiation for nitrate removal from aqueous solution  

Microsoft Academic Search

Groundwater contaminated by nitrate has become a worldwide problem. Existing technologies for nitrate removal, including zero-valent iron reduction, can only transform nitrate ions to predominantly NH4+. As a result, many studies have concentrated on seeking a solution to convert nitrate to N2. In this study, the efficiencies of nitrate removal from aqueous solution by single (TiO2 and nano zero valent

Jill Ruhsing Pan; Chihpin Huang; Wen-Pin Hsieh; Bi-Ju Wu

20

Sorption of lanthanide from aqueous organic solutions of nitric acid and nitrates  

SciTech Connect

We have studied the sorption of lanthanide radionuclides on the anion exchanger Dowex 1x8 from aqueous organic solutions of nitric acid and nitrates (ammonium, lithium, aluminum). As the organic solvents, we use ethanol, acetone, acetonitrile, and dimethylsulfoxide. We have shown that the change in sorbability of the lanthanides is due to the solvating donor-acceptor ability of the organic solvents.

Sheveleva, I.V.; Bogatyrev, I.O.

1988-05-01

21

Study of Gelation in Aqueous Solutions of Cysteine and Silver Nitrate  

Microsoft Academic Search

A gel based on aqueous solutions of cysteine and silver nitrate is obtained for the first time. The possibility of gelation in the presence of competing ions and ligands is studied. Structural transformations occurring at an early stage of the gelation are studied by the dynamic light scattering, IR Fourier spectroscopy, and viscometry. The process of the self-organization in the

P. M. Pakhomov; M. M. Ovchinnikov; S. D. Khizhnyak; M. V. Lavrienko; W. Nierling; M. D. Lechner

2004-01-01

22

Hydrogen bond lengths in aqueous hydroxylammonium nitrate as a function of concentration, temperature and pressure  

Microsoft Academic Search

Qualitative and quantitative information about the interspecies distance distributions in aqueous hydroxylammonium nitrate (HAN) is obtained as a function of concentration (7 to 17M), temperature (-120 to 60°C) and pressure (0.1 to 7100 MPa) using isotopic uncoupling techniques for the O-H?O and N-H?O hydrogen bonds in conjunction with frequency-distance correlations.

Robert A. Fifer

1988-01-01

23

Solubility of indium monobromide in water and in aqueous potassium nitrate solutions  

SciTech Connect

The disproportionation of indium monobromide in water at 25/sup 0/C proceeds only to a limited extent. The solubility of InBr in water in 8.3 x 10/sup -3/ M, and in 2 M potassium nitrate solution 1.32 x 10/sup -2/ M. Characteristic for the dissolution of InBr in aqueous potassium nitrate solutions is inhibition of the disproportionation of univalent indium ions that have passed into solution, and also the occurrence (at a test solution pH above 2) of oxidative hydrolysis, accompanied by the formation of a white precipitate of trivalent indium hydroxide.

Egorova, A.G.; Nefedov, A.N.

1986-04-20

24

Radiolysis of hexavalent plutonium in solutions of uranyl nitrate containing fission product simulants  

NASA Astrophysics Data System (ADS)

The effect of the inherent radioactivity on the chemical state of plutonium ions in solution was recognized very shortly after the first macroscopic amounts of plutonium became available and early studies were conducted as part of the Manhattan Project. However, the behavior of plutonium ions, in nitric acid especially, has been found to be somewhat complex, so much so that a relatively modern summary paper included the comment that, ``The vast amount of work carried out in nitric acid solutions can not be adequately summarized. Suffice it to say results in these solutions are plagued with irreproducibility and induction periods...'' Needless to say, the presence of other ions in solution, as occurs when irradiated nuclear fuel is dissolved, further complicates matters. The purpose of the work described below was to add to the rather small amount of qualitative data available relating to the radiolytic behavior of plutonium in solutions of irradiated nuclear fuel. .

Rance, Peter J. W.; Zilberman, B. Ya.; Akopov, G. A.

2000-07-01

25

Plutonium  

NASA Astrophysics Data System (ADS)

The element plutonium occupies a unique place in the history of chemistry, physics, technology, and international relations. After the initial discovery based on submicrogram amounts, it is now generated by transmutation of uranium in nuclear reactors on a large scale, and has been separated in ton quantities in large industrial facilities. The intense interest in plutonium resulted fromthe dual-use scenario of domestic power production and nuclear weapons - drawing energy from an atomic nucleus that can produce a factor of millions in energy output relative to chemical energy sources. Indeed, within 5 years of its original synthesis, the primary use of plutonium was for the release of nuclear energy in weapons of unprecedented power, and it seemed that the new element might lead the human race to the brink of self-annihilation. Instead, it has forced the human race to govern itself without resorting to nuclear war over the past 60 years. Plutonium evokes the entire gamut of human emotions, from good to evil, from hope to despair, from the salvation of humanity to its utter destruction. There is no other element in the periodic table that has had such a profound impact on the consciousness of mankind.

Clark, David L.; Hecker, Siegfried S.; Jarvinen, Gordon D.; Neu, Mary P.

26

Aqueous-phase nitration of phenol by N 2O 5 and ClNO 2  

NASA Astrophysics Data System (ADS)

Nitrophenols are present in the atmospheric gas phase and in cloud and rainwater. Their formation via aqueous-phase reactions of phenol with the nitronium ion, NO 2+, arising from N 2O 5 and ClNO 2 partitioning into the aqueous phase, has been proposed but not verified experimentally. Here, we demonstrate for the first time that gaseous N 2O 5 and ClNO 2 partitioning into dilute aqueous solutions of phenol yields 2- and 4-nitrophenol (and 4-nitrosophenol), but no dinitrophenol isomers. The rate of nitration does not vary significantly between 5 and 20 °C, presumably because of opposing temperature dependences in Henry's law partitioning and reaction rate coefficients. The rate coefficient for reaction of NO 2+ with phenol could not be directly quantified but is evidently large enough for this reaction to compete effectively with the reaction between NO 2+ and water and to provide a feasible route to nitrophenol production in the atmosphere.

Heal, Mathew R.; Harrison, Mark A. J.; Neil Cape, J.

27

Detection of the improvised explosives ammonium nitrate (AN) and urea nitrate (UN) using non-aqueous solvents with electrospray ionization and MS/MS detection.  

PubMed

In this study methods for the detection of trace levels of the improvised explosives urea nitrate and ammonium nitrate were developed using electrospray ionization with infusion. By using a non-aqueous solvent mixture containing 95% acetone with 5% 2-methoxyethanol we were able to preserve the urea and ammonium nitrate ion pairs and discriminate between these and other similar salts. Negative ion electrospray ionization was used for urea nitrate detection and positive ion electrospray ionization was used for ammonium nitrate. Two specific adduct ions were detected for each explosive with ammonium nitrate producing m/z 178 [2AN+NH4](+) and m/z 258 ions [3AN+NH4](+) while urea nitrate produced m/z 185 [UN+NO3](-) and m/z 248 [UN+HNO3+NO3](-) The specificity of the analysis was examined by mixing the different explosives with various salts and interferents. Adduct ions formed in the gas phase were found to be useful in distinguishing between ion pairs and mixed salts. Overall the method demonstrates the sensitive detection of both explosives, and more specifically the potential to determine intact urea nitrate. PMID:24054629

Corbin, Inge; McCord, Bruce

2013-10-15

28

Structure of aqueous ammonium calcium nitrate glass former studied by neutron diffraction  

NASA Astrophysics Data System (ADS)

A neutron diffraction experiment was carried out on the glass-forming aqueous system of ammonium calcium nitrate tetrahydrate, ACN (NH4NO3.Ca(NO3)2.4H2O). The method of isotopic substitution was used to determine the local structure round the NO-3 ion, the hydrogen-hydrogen (gHH(r)), the hydrogen-oxygen (gOH(r)), and the nitrogen-hydrogen (gN2H(r)) radial pair distribution functions, in both the glassy (153 K) and liquid (303 K) states. The results show that significant changes occur on glassification. In particular, the nitrate ion exhibits an increase in the number of close hydrogen contacts and enhancement of its local structure. A microstructural model is proposed to explain the strong glass-forming ability of ACN.

Ansell, S.; Neilson, G. W.

1999-09-01

29

Room temperature electrodeposition and characterization of bismuth ferric oxide (BFO) thin films from aqueous nitrate bath  

NASA Astrophysics Data System (ADS)

Bismuth ferric oxide (BFO) thin films were prepared on fluorine doped tin oxide (FTO) coated glass substrates using electrodeposition method from aqueous nitrate bath at room temperature. The various preparative parameters, such as bath composition, current density, deposition time, etc were optimized to get good quality BFO thin films. The structural, surface morphological, optical and dielectrical properties of the films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), optical absorption and dielectric measurement techniques. The results show that electrodeposition method allows to synthesis BFO films. The films are free from pinholes and cracks. The magnitudes of dielectric constant and loss tangent showed inverse frequency dependence.

Gujar, T. P.; Shinde, V. R.; Kulkarni, S. S.; Pathan, H. M.; Lokhande, C. D.

2006-03-01

30

Structure of aqueous ammonium calcium nitrate glass former studied by neutron diffraction  

Microsoft Academic Search

A neutron diffraction experiment was carried out on the glass-forming aqueous system of ammonium calcium nitrate tetrahydrate, ACN (NH4NO3.Ca(NO3)2.4H2O). The method of isotopic substitution was used to determine the local structure round the NO-3 ion, the hydrogen-hydrogen (gHH(r)), the hydrogen-oxygen (gOH(r)), and the nitrogen-hydrogen (gN2H(r)) radial pair distribution functions, in both the glassy (153 K) and liquid (303 K) states.

S. Ansell; G. W. Neilson

1999-01-01

31

Protein aggregation and partial globular state in aqueous 1-alkyl-3-methylimidazolium nitrate solutions  

NASA Astrophysics Data System (ADS)

We have investigated the relationship between protein size and the structural modification in concentrated aqueous solutions of ionic liquids (ILs) 1-alkyl-3-methylimidazolium nitrate ([Cnmim][NO3] (n = 2, 4)). Proteins with the radii of gyration (Rg) above ?20 Å form amorphous aggregates in an aqueous [C4mim][NO3] solution at X (mol% IL) = 20, whereas those with Rg values below ?20 Å assume partial globular states. Remarkably, a decrease in the alkyl-chain length causes an increase in the protein size at which protein aggregation occurs. Concentrated [Cnmim][NO3] (n = 2, 4) solutions might control a boundary between the protein aggregation and partial globular states.

Takekiyo, Takahiro; Fukudome, Keisuke; Yamazaki, Kumiko; Abe, Hiroshi; Yoshimura, Yukihiro

2014-05-01

32

Structure Determination of Plutonium Oxide Precipitates Formed from Aqueous Plutonium IV and V Solutions and in the Presence of Goethite  

NASA Astrophysics Data System (ADS)

A series of aqueous Pu(IV) and Pu(V) batch sorption experiments with goethite (?-FeOOH) in a pH 8 ± 0.5 buffer solution (5mM NaCl + 0.7 mM NaHCO3) at room temperature (25 °C) were performed. Intrinsic Pu colloids were synthesized in alkaline solution (pH 8, 25 °C) and acidic solution (0.1 M HNO3, ~80 °C for 10-20 min), respectively, for comparison. Morphology, distribution and crystal structure of Pu oxide precipitates, as well as interaction between the Pu precipitates and goethite, were investigated using transmission electron microscopy (TEM). The Pu oxide precipitates formed from the sorption experiments consist of 3-5 nm primary crystalline particles (nanocrystals) irrespective of the initial form of Pu. The Pu oxide nanocrystals adopt two different crystal structures, either fcc PuO2 or bcc Pu4O7. The relative abundance of one form over the other depends on the initial form of Pu, Pu concentration, and the presence of goethite. For the high Pu concentration sorption cases (>9,000 nmol/m2 goethite), fcc PuO2 is the predominant phase occurring in both aqueous Pu(IV) and Pu(V) samples. In the Pu(IV) samples, the fcc PuO2 nanocrystals form mainly as a product of hydrolysis in solution. In the Pu(V) samples, the fcc PuO2 nanocrystals form by redox reactions dominantly occurring on goethite surface following the sorption of Pu(V). At lower Pu concentrations, the bcc Pu4O7 becomes dominant in the presence of goethite. The bcc Pu4O7 forms directly on the goethite surface as a 3-5 nm isolated nanocrystal in both Pu(IV) and Pu(V) samples and has specific crystallographic orientation relationships to goethite. Nucleation of the bcc Pu4O7 may occur by substitution of Pu(III) at the Fe(III) position on the goethite surface. In the absence of goethite, the intrinsic Pu colloids formed in alkaline solution (pH 8, 25 °C) are also comprised of 3-5 nm fcc PuO2 nanocrystals. As for the intrinsic Pu colloids precipitated from the acidic solution (0.1 M HNO3) at an elevated temperature, their solution exhibits the classic green color attributed to colloidal Pu(IV)[1], but the constitutive fcc PuO2 nanocrystals are only 2-3 nm in diameter. The 2-3nm PuO2 nanocrystals can self-assemble to form 10 nm to 100 nm Pu colloidal aggregates that produce electron diffraction patterns that are indicative of much larger well ordered "single crystals" of PuO2. [1] Cleveland, J. M. The Chemistry of Plutonium; The American Nuclear Society: La Grange Park, Illinois, 1979. This work was funded by U. S. DOE Office of Biological & Environmental Sciences, Subsurface Biogeochemistry Research Program, and performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Security, LLC under Contract DE-AC52-07NA27344.

Dai, Z.; Zavarin, M.; Zhao, P.; Begg, J.; Kersting, A. B.

2012-12-01

33

D Structure of Aqueous Solutions of Cobalt(II) Nitrate at 298 and 323 K by X-Ray Diffraction  

Microsoft Academic Search

Aqueous solutions of cobalt(II) nitrate with 1 : 15, 1 : 25, and 1 : 40 mole ratios at 298 and 323 K were studied by the X-ray diffraction. As the solution concentration decreases, ion triads (1 : 15) pass into contact ion pairs (1 : 25) and then to independently hydrated ions (1 : 40). The structural variations are

S. F. Levochkin; P. R. Smirnov; V. N. Trostin

2005-01-01

34

Criticality Experiments with Mixed Plutonium and Uranium Nitrate Solution at a Plutonium Fraction of 0.5 in Annular Cylindrical Geometry  

SciTech Connect

A series of critical experiments was completed with mixed plutonium-uranium solutions having Pu/(Pu + U) ratios of approximately 0.5. These experiments were a part of the Criticality Data Development Program between the United States Department of Energy (USDOE), and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of, and data from, the experiments are included in this report. The experiments were performed with mixed plutonium-uranium solutions in annular cylindrical geometry. The measurements were made with a water reflector. The central region included a concrete annular cylinder containing B{sub 4}C. Interior to the concrete insert was a stainless steel bottle containing plutonium-uranium solution. The concentration of the solution in the annular region was varied from 116 to 433 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was 52% for all experiments.

Lloyd, RC

1988-04-01

35

Criticality Experiments with Mixed Plutonium and Uranium Nitrate Solution at a Plutonium Fraction of 0.4 in Slab and Cylindrical Geometry  

SciTech Connect

A series of critical experiments was completed with mixed plutonium-uranium solutions having Pu/(Pu + U) ratios of approximately 0.4. These experiments were a part of the Criticality Data Development Program between the United States Department of Energy (USDOE), and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of, and data from, the experiments are included in this report. The experiments were performed with mixed plutonium-uranium solutions in cylinqrical and slab geometries and included measurements with a water reflector, a concrete reflector, and without an added reflector. The concentration was varied from 105 to 436 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was 0.4 for all experiments.

Lloyd, RC

1988-04-01

36

NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN  

Microsoft Academic Search

Reillex{trademark} HPQ ion exchange resin is used by HB Line to remove plutonium from aqueous streams. Reillex{trademark} HPQ resin currently available from Vertellus Specialties LLC is a chloride ionic form, which can cause stress corrosion cracking in stainless steels. Therefore, HB Line Engineering requested that Savannah River National Laboratory (SRNL) convert resin from chloride form to nitrate form in the

J. Steimke; M. Williams; T. Steeper; R. Leishear

2012-01-01

37

Solubility of hydrogen sulfide in aqueous solutions of single strong electrolytes sodium nitrate, ammonium nitrate, and sodium hydroxide at temperatures from 313 to 393 K and total pressures up to 10 MPa  

Microsoft Academic Search

New experimental results for the solubility of hydrogen sulfide in aqueous solutions of the single strong electrolytes sodium nitrate, ammonium nitrate, and sodium hydroxide at temperatures from 313 to 393 K and total pressures up to 10 MPa are reported. As in the strong electrolyte-free system, a second — hydrogen sulfide-rich — liquid phase is observed at high hydrogen sulfide

Jianzhong Xia; Álvaro Pérez-Salado Kamps; Bernd Rumpf; Gerd Maurer

2000-01-01

38

Isotopes for improved management of nitrate pollution in aqueous resources: review of surface water field studies  

NASA Astrophysics Data System (ADS)

For water bodies where the nitrate concentrations exceed threshold values environmental agencies can propose measures to either reduce discharges and emissions of nitrate or to remediate nitrate polluted water bodies. Isotope data can support the identification of nitrate pollution sources and natural attenuation processes of nitrate. A review of surface water field studies evaluated the use of isotope data (e.g. ?15N, ?18O and ?17O of nitrate, ?18O of water, ?11B of boron) in environmental monitoring of nitrate pollution in forested, agricultural, mixed and urban watersheds. An overview of the information available to date regarding nitrate source apportionment studies in surface waters is given with the intention to help to improve future studies. An appropriate sampling strategy and statistical approach needs to be developed by means of available data on possible nitrate sources, hydrology and land use. Also transformation, transport and mixing process should be considered since these can change the isotope composition of the original nitrate source. Nitrate isotope data interpreted in combination with hydrological and chemical data provide valuable information on the nitrate pollution sources and on the processes nitrate has undergone during its retention and transport in the watershed. This information is useful for the development of an appropriate water management policy.

Nestler, A.; Berglund, M.; Accoe, F.; Duta, S.; Xue, D.; Boeckx, P. F.; Taylor, P.

2010-12-01

39

Complexation and redox interactions between aqueous plutonium and manganese oxide interfaces  

SciTech Connect

The sorption of Pu(VI) and Pu(V) onto manganite (MnOOH) and Hausmannite (Mn3O4) was studied at pH 5. Manganite sorbed 21-24% from a 1x10-4 M plutonium solution and the hausmannite removed between 43-66% of the plutonium. The increased sorption by hausmannite results from its larger surface area (about twice that of manganite) plus a larger number of active surface sites. X-ray absorption near-edge structure (XANES) spectra taken at the Pu LIII edge were compared to standard spectra of plutonium in single oxidation states. Based on these spectra, it appears that both manganite and hausmannite reduce the higher valent plutonium species to Pu(IV). Between 53-59% of the plutonium was present as Pu(IV) in the manganite samples while 55-61% of the plutonium complexed to the hausmannite had also been reduced to Pu(IV). The exact mechanism behind this redox interaction between the plutonium and the manganese needs to be identified.

Shaughnessy, Dawn A.; Nitsche, Heino; Booth, Corwin H.; Shuh, David K.; Waychunas, Glenn A.; Wilson, Richard E.; Cantrell, Kirk J.; Serne, R. Jeffrey

2001-11-01

40

Luminescence, absorption, and Stern-Volmer studies of cerium chloride and nitrate compounds in acidic and neutral aqueous, and non-aqueous solutions.  

PubMed

Complexation of cerium chloride and nitrate in neutral and acidic aqueous solutions as well as in anhydrous alcohol solutions were investigated using emission, excitation, and absorption spectroscopic techniques. In aqueous solution cerium chloride shows a strong, and broad emission centering at 365 nm. The excitation spectra are observed at 266 and 296 nm with the shorter wavelength showing the highest intensity. Cerium chloride compound also strongly emits in methanol (MeOH), where the broad emission spectrum is red shifted by ?10-375 nm. The excitation spectrum in MeOH shows bands at 255 and 309 nm, respectively with the longer wavelength band (at 309 nm) dominating. The relative intensities of these two excitation bands are reversed in protic aqueous solution. In contrast, solutions of cerium nitrate are only weakly luminescent in aqueous media, while the emission is totally quenched in MeOH solution. These observations indicate that the spectral profiles are largely influenced by the extent of inner-sphere coordination and the type of the dominant species in solutions. Both nitrate and chloride anions show enhanced inner-sphere coordination in MeOH when compared with that of the aqueous media. However, enhanced inner-sphere complexation of the NO(3)(-) ion quenches the emission, while the reverse effect is observed upon Cl(-) coordination. Stern-Volmer studies provide quenching constant, K(sv), value of 577M(-1). The calculated rate constant k(r) is 1.3×10(10)M(-1)s(-1) indicating diffusion controlled bimolecular process as the major mode of interaction. PMID:23261607

Forcha, Derick; Brown, Kwame J; Assefa, Zerihun

2013-02-15

41

Luminescence, absorption, and Stern-Volmer studies of cerium chloride and nitrate compounds in acidic and neutral aqueous, and non-aqueous solutions  

NASA Astrophysics Data System (ADS)

Complexation of cerium chloride and nitrate in neutral and acidic aqueous solutions as well as in anhydrous alcohol solutions were investigated using emission, excitation, and absorption spectroscopic techniques. In aqueous solution cerium chloride shows a strong, and broad emission centering at 365 nm. The excitation spectra are observed at 266 and 296 nm with the shorter wavelength showing the highest intensity. Cerium chloride compound also strongly emits in methanol (MeOH), where the broad emission spectrum is red shifted by ˜10-375 nm. The excitation spectrum in MeOH shows bands at 255 and 309 nm, respectively with the longer wavelength band (at 309 nm) dominating. The relative intensities of these two excitation bands are reversed in protic aqueous solution. In contrast, solutions of cerium nitrate are only weakly luminescent in aqueous media, while the emission is totally quenched in MeOH solution. These observations indicate that the spectral profiles are largely influenced by the extent of inner-sphere coordination and the type of the dominant species in solutions. Both nitrate and chloride anions show enhanced inner-sphere coordination in MeOH when compared with that of the aqueous media. However, enhanced inner-sphere complexation of the NO3- ion quenches the emission, while the reverse effect is observed upon Cl- coordination. Stern-Volmer studies provide quenching constant, Ksv, value of 577 M-1. The calculated rate constant kr is 1.3 × 1010 M-1 s-1 indicating diffusion controlled bimolecular process as the major mode of interaction.

Forcha, Derick; Brown, Kwame J.; Assefa, Zerihun

2013-02-01

42

Spectrophotometric Determination of Trace Uranium in Plutonium Nitrate and Oxide with 2-(2-Pyridylazo)-5-Diethylaminophenol.  

National Technical Information Service (NTIS)

A spectrophotometric method for the determination of trace uranium in plutonium was developed and evaluated. Uranium was separated from plutonium in a 4M HCl-2M NH sub 2 OH.HCl matrix with Aliquat-336. The uranium in the organic was determined by spectrop...

W. I. Winters

1975-01-01

43

Criticality Experiments with Mixed Plutonium and Uranium Nitrate Solution at a Plutonium Fraction of 0.2 and 1.0 in Annular Cylindrical Geometry  

SciTech Connect

A series of critical experiments was completed with mixed plutoniumuranium solutions having Pu/(Pu + U) ratios of approximately 0.2 and 1.0. These experiments were a part of the Criticality Data Development Program between the United States Department of Energy (USDOE), and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan. A complete description of, and data from, the experiments are included in this report. The experiments were performed with mixed plutonium-uranium solutions in annular cylindrical geometry. The measurements were made with a water reflector. The central region included a concrete, polyethylene or void annular cylindrical insert. Interior to the insert was a stainless steel bottle containing plutonium-uranium solution or a void region. In one experiment the central region was filled with a solid cadmium-covered polyethylene insert. The concentration of the solution in the annular region was varied from 61 to 489 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was 0.22 or 0.97 for all experiments.

Lloyd, RC

1988-04-01

44

Enzymically accelerated biomineralization of heavy metals: application to the removal of americium and plutonium from aqueous flows.  

PubMed

A biological process for the removal of heavy metals from the aqueous flows is described. Metals are precipitated on the surface of immobilized cells of a Citrobacter sp. as cell-bound metal phosphates. This uses phosphate liberated by the activity of a cell-bound phosphatase. Some radionuclides (e.g. 241americium) form metal phosphates readily; efficient removal of 241Am on a continuous basis is demonstrated. At low phosphatase activities, the efficiency of uranium removal correlates with enzyme activity. High phosphatase activities are not realised as an increase in metal removal, suggesting that chemical events become rate-limiting. Studies have suggested that maximal metal uptake occurs only after nucleation and the formation of precipitation foci. A model is presented to illustrate how nucleation and crystallization processes could enhance the removal of plutonium and neptunium from dilute solutions. PMID:7917422

Macaskie, L E; Jeong, B C; Tolley, M R

1994-08-01

45

Aqueous biphasic plutonium oxide extraction process with pH and particle control  

DOEpatents

A method is described for simultaneously partitioning a metal oxide and silica from a material containing silica and the metal oxide, using a biphasic aqueous medium having immiscible salt and polymer phases. 2 figs.

Chaiko, D.J.; Mensah-Biney, R.

1997-04-29

46

An Electronic Tongue Designed to Detect Ammonium Nitrate in Aqueous Solutions  

PubMed Central

An electronic tongue has been developed to monitor the presence of ammonium nitrate in water. It is based on pulse voltammetry and consists of an array of eight working electrodes (Au; Pt; Rh; Ir; Cu; Co; Ag and Ni) encapsulated in a stainless steel cylinder. In a first step the electrochemical response of the different electrodes was studied in the presence of ammonium nitrate in water in order to further design the wave form used in the voltammetric tongue. The response of the electronic tongue was then tested in the presence of a set of 15 common inorganic salts; i.e.; NH4NO3; MgSO4; NH4Cl; NaCl; Na2CO3; (NH4)2SO4; MgCl2; Na3PO4; K2SO4; K2CO3; CaCl2; NaH2PO4; KCl; NaNO3; K2HPO4. A PCA plot showed a fairly good discrimination between ammonium nitrate and the remaining salts studied. In addition Fuzzy Art map analyses determined that the best classification was obtained using the Pt; Co; Cu and Ni electrodes. Moreover; PLS regression allowed the creation of a model to correlate the voltammetric response of the electrodes with concentrations of ammonium nitrate in the presence of potential interferents such as ammonium chloride and sodium nitrate.

Campos, Inmaculada; Pascual, Lluis; Soto, Juan; Gil-Sanchez, Luis; Martinez-Manez, Ramon

2013-01-01

47

An electronic tongue designed to detect ammonium nitrate in aqueous solutions.  

PubMed

An electronic tongue has been developed to monitor the presence of ammonium nitrate in water. It is based on pulse voltammetry and consists of an array of eight working electrodes (Au; Pt; Rh; Ir; Cu; Co; Ag and Ni) encapsulated in a stainless steel cylinder. In a first step the electrochemical response of the different electrodes was studied in the presence of ammonium nitrate in water in order to further design the wave form used in the voltammetric tongue. The response of the electronic tongue was then tested in the presence of a set of 15 common inorganic salts; i.e.; NH?NO?; MgSO?; NH?Cl; NaCl; Na?CO?; (NH?)?SO?; MgCl?; Na?PO?; K?SO?; K?CO?; CaCl?; NaH?PO?; KCl; NaNO?; K?HPO?. A PCA plot showed a fairly good discrimination between ammonium nitrate and the remaining salts studied. In addition Fuzzy Art map analyses determined that the best classification was obtained using the Pt; Co; Cu and Ni electrodes. Moreover; PLS regression allowed the creation of a model to correlate the voltammetric response of the electrodes with concentrations of ammonium nitrate in the presence of potential interferents such as ammonium chloride and sodium nitrate. PMID:24145916

Campos, Inmaculada; Pascual, Lluis; Soto, Juan; Gil-Sánchez, Luis; Martínez-Máez, Ramón

2013-01-01

48

Oxidation of ferrocenes by copper(II) in aqueous acetonitrile: nitrate and chloride ion effects.  

PubMed

The effect of nitrate and chloride ion on the rate of oxidation of ferrocene (Fc) and 1,1'-dimethylferrocene (DmFc) by Cu(II) has been studied in 95% and 80% acetonitrile/water solutions. The complex formation constants for Cu(II) with the same anions in the same media have been determined by spectrophotometry. Nitrate ion mildly inhibits the reaction, while chloride ion substantially increases the rate. The results have been analyzed in terms of the Marcus theory, and it is concluded that complexation increases the rate of self-exchange between the CuII(X)n and CuI(X)n species. In the case of nitrate, the latter effect is compensated for by a less favorable overall equilibrium constant, which results in mild inhibition. PMID:17253680

Irangu, Japhet; Jordan, Robert B

2007-02-19

49

Temperature dependence of distribution coefficients in uranyl nitrate extraction from aqueous solutions  

Microsoft Academic Search

Oi;ttibution coefficients in ur~vb-I nitrate extractf~rt ~:r~ aqueo~ ~,~tw.ions by ttlbutyI phosphate tolulions in b.nzcnc wc~c mcas;Lr,-~.at temperatures of I+. ~$. ~. 25. -~5. and 85% L|, Ha, K, Cs, Mg,Ca; NI. Zn, St, CO. Ba. and Ph r.~cs at various c,'.,acerm':mi.~r~ were ~_r as salting-out agents. As in uranyl nitrate extraction fror,w &~u'cous solution, h~ d~':.~'l ether, ~c :fficfency

R. T. Golovatenko; O. Ya. Samollov

1962-01-01

50

Carcinogenesis and Inflammatory Effects of Plutonium-Nitrate Retention in an Exposed Nuclear Worker and Beagle Dogs.  

SciTech Connect

The genetic and inflammatory response pathways elicited following plutonium exposure in archival lung tissue of an occupationally exposed human and experimentally exposed beagle dogs were investigated. These pathways include: tissue injury, apoptosis and gene expression modifications related to carcinogenesis and inflammation. In order to determine which pathways are involved, multiple lung samples from a plutonium exposed worker (Case 0269), a human control (Case 0385), and plutonium exposed beagle dogs were examined using histological staining and immunohistochemistry. Examinations were performed to identify target tissues at risk of radiation-induced fibrosis, inflammation, and carcinogenesis. Case 0269 showed interstitial fibrosis in peripheral and subpleural regions of the lung, but no pulmonary tumors. In contrast, the dogs with similar and higher doses showed pulmonary tumors primarily in brochiolo-alveolar, peripheral and subpleural alveolar regions. The TUNEL assay showed slight elevation of apoptosis in tracheal mucosa, tumor cells, and nuclear debris was present in the inflammatory regions of alveoli and lymph nodes of both the human and the dogs. The expression of apoptosis and a number of chemokine/cytokine genes was slightly but not significantly elevated in protein or gene levels compared to that of the control samples. In the beagles, mucous production was increased in the airway epithelial goblet cells and glands of trachea, and a number of chemokine/cytokine genes showed positive immunoreactivity. This analysis of archival tissue from an accidentally exposed worker and in a large animal model provides valuable information on the effects of long-term retention of plutonium in the respiratory tract and the histological evaluation study may impact mechanistic studies of radiation carcinogenesis.

Nielsen, Christopher E.; Wang, Xihai; Robinson, Robert J.; Brooks, Antone L.; Lovaglio, Jamie A.; Patton, Kristin M.; McComish, Stacey; Tolmachev, Sergei Y.; Morgan, William F.

2014-01-01

51

Chemical species of plutonium in Hanford radioactive tank waste  

SciTech Connect

Large quantities of radioactive wastes have been generated at the Hanford Site over its operating life. The wastes with the highest activities are stored underground in 177 large (mostly one million gallon volume) concrete tanks with steel liners. The wastes contain processing chemicals, cladding chemicals, fission products, and actinides that were neutralized to a basic pH before addition to the tanks to prevent corrosion of the steel liners. Because the mission of the Hanford Site was to provide plutonium for defense purposes, the amount of plutonium lost to the wastes was relatively small. The best estimate of the amount of plutonium lost to all the waste tanks is about 500 kg. Given uncertainties in the measurements, some estimates are as high as 1,000 kg (Roetman et al. 1994). The wastes generally consist of (1) a sludge layer generated by precipitation of dissolved metals from aqueous wastes solutions during neutralization with sodium hydroxide, (2) a salt cake layer formed by crystallization of salts after evaporation of the supernate solution, and (3) an aqueous supernate solution that exists as a separate layer or as liquid contained in cavities between sludge or salt cake particles. The identity of chemical species of plutonium in these wastes will allow a better understanding of the behavior of the plutonium during storage in tanks, retrieval of the wastes, and processing of the wastes. Plutonium chemistry in the wastes is important to criticality and environmental concerns, and in processing the wastes for final disposal. Plutonium has been found to exist mainly in the sludge layers of the tanks along with other precipitated metal hydrous oxides. This is expected due to its low solubility in basic aqueous solutions. Tank supernate solutions do not contain high concentrations of plutonium even though some tanks contain high concentrations of complexing agents. The solutions also contain significant concentrations of hydroxide which competes with other potential complexants. The sodium nitrate and sodium phosphate salts that form most of the salt cake layers have little interaction with plutonium in the wastes and contain relatively small plutonium concentrations. For these reasons the authors consider plutonium species in the sludges and supernate solutions only. The low concentrations of plutonium in waste tank supernate solutions and in the solid sludges prevent identification of chemical species of plutonium by ordinary analytical techniques. Spectrophotometric measurements are not sensitive enough to identify plutons oxidation states or complexes in these waste solutions. Identification of solid phases containing plutonium in sludge solids by x-ray diffraction or by microscopic techniques would be extremely difficult. Because of these technical problems, plutonium speciation was extrapolated from known behavior observed in laboratory studies of synthetic waste or of more chemically simple systems.

Barney, G.S.

1997-10-22

52

Activity coefficients of sodium, potassium, and nitrate ions in aqueous solutions of NaNO 3 , KNO 3 , and NaNO 3 +KNO 3 at 25°C  

Microsoft Academic Search

Ion selective electrodes have been used to measure the activity coefficients at 25°C of individual ions in aqueous solutions of NaNO3 up to 3.5 molal, KNO3 up to 3.5 molal and mixtures of NaNO3 and KNO3 up to 2.4 molal total nitrate ion concentration. The experimental results confirm that the activity coefficient of anion and cation in aqueous single electrolyte

Maria der Mar Marcos-Arroyo; Mohammad K. Khoshkbarchi; Juan H. Vera

1996-01-01

53

Concentration and Pressure Effects on the Decomposition Rate of Aqueous Hydroxylammonium Nitrate Solutionsa  

Microsoft Academic Search

Abstract— Decomposition experiments have been performed on liquid propellants consisting of mixtures of hydroxylammonium nitrate (HAN) and water. Electric discharge initiation was used to produce a propagating, exothermic decomposition wave front, which was then observed by cineshadowgraphy. Experiments were conducted on quiescent HAN-water mixtures of 3.12 to 13.00M HAN in a 1.8 x 1.0mm rectangular strand burner over pressures of

Steven R. Vosen

1989-01-01

54

Preparation of activated carbons from Iris tectorum employing ferric nitrate as dopant for removal of tetracycline from aqueous solutions.  

PubMed

Ferric nitrate was employed to modify activated carbon prepared from Iris tectorum during H?PO? activation and ability of prepared activated carbon for removal of tetracycline (TC) was investigated. The properties of the activated carbon samples with or without ferric nitrate, ITAC-Fe and ITAC, were measured by scanning electron microscopy (SEM), N? adsorption/desorption isotherms, Fourier transform infrared spectroscopy (FTIR) and Boehm's titration. The results showed that mixing with iron increased the BET surface area, total pore volume and the adsorption capacity as compared to the original carbon. FTIR and Boehm's titration suggested that ITAC-Fe was characteristic of more acidic functional groups than ITAC. Adsorption of TC on both samples exhibited a strong pH-dependent behavior and adsorption capacity reduced rapidly with the increasing solution pH. The adsorption kinetics agreed well with the pseudo-second-order model and the adsorption isotherms data were well described by Langmuir model with the maximum adsorption capacity of 625.022 mg/g for ITAC and 769.231 mg/g for ITAC-Fe. The present work suggested that ITAC-Fe could be used to remove tetracycline effectively from aqueous solutions. PMID:24021870

Li, Gang; Zhang, Dongsheng; Wang, Man; Huang, Ji; Huang, Lihui

2013-12-01

55

Alloy 22 Localized Corrosion Susceptibility In Aqueous Solutions Of Chloride And Nitrate Salts Of Sodium And Potassium At 110 - 150?C  

SciTech Connect

Alloy 22 (a nickel-chromium-molybdenum-tungsten alloy) is being investigated for use as the outer barrier of waste containers for a high-level nuclear waste repository in the thick unsaturated zone at Yucca Mountain, Nevada. Experiments were conducted to assess crevice corrosion of Alloy 22 in de-aerated aqueous solutions of chloride and nitrate salts of potassium and sodium in the temperature range 110-150 C (some limited testing was also conducted at 90 C). Electrochemical tests were run in neutral salt solutions without acid addition and others were run in salt solutions with an initial hydrogen ion concentration of 10{sup -4} molal. The Alloy 22 specimens were weld prism specimens and de-aeration was performed with nitrogen gas. No evidence of crevice corrosion was observed in the range 125-150 C. In the 120 to 160 C temperature range, the anionic concentration of stable aqueous solutions is dominated by nitrate relative to chloride. At nominally 120 C, the minimum nitrate to chloride ratio is about 4.5, and it increases to about 22 at nominally 155 C. The absence of localized corrosion susceptibility in these solutions is attributed to the known inhibiting effect of the nitrate anion. At 110 C, aqueous solutions can have dissolved chloride in excess of nitrate. Localized corrosion was observed at nitrate to chloride ratios up to 1.0, the highest ratio tested. The extent of localized corrosion was confined to the crevice region of the samples, and was limited for nitrate to chloride ratios greater than or equal to 0.3. Aqueous solution chemistry studies indicate that nitrate to chloride ratios of less than 0.5 are possible for temperatures up to nominally 116 C. However, the exact upper temperature limit is unknown and no electrochemical testing was done at these temperatures. Limited comparison between 8 m Cl aqueous solutions of Na + K on the one hand and Ca on the other indicated similar electrochemical E{sub crit} values and similar morphology of attack, again limited to the crevice region. However, the 24 hr E{sub corr} value was higher for the Ca based solution; this is probably due to the higher acidity of this solution (Ca{sup 2+} is slightly hydrolyzing). Intermediate-term corrosion potential (E{sub corr}) measurements indicate that moderately acidic conditions are required to achieve elevated E{sub corr} values.

Felker, S; Hailey, P D; Lian, T; Staggs, K J; Gdowski, G E

2006-01-17

56

Measurements of Al(NO 3) 3 activities in aqueous nitrate solutions  

NASA Astrophysics Data System (ADS)

Aluminum nitrate activity coefficients obtained by vapor pressure osmometry are compared with activity coefficients derived from nitric acid extraction measurements and Bromley's correlation. This solvent extraction approach was possible because of the poor extraction of Al 3+ (distribution ratio ? 10 3) by the chosen solvents. The solvents compositions were 0.25M CMPO (octyl(phenyl)-N, N-diisobutylcarbamoyl methylphosphine oxide) in tetrachloroethylene (TCE) and 0.25M CMPO with 0.75M tributyl phosphate (TBP) in TCE. In both approaches, nitric acid was used to supress the hydrolysis of Al 3+. At high ionic strengths, the two techniques yielded very similar activity coefficients for Al(NO 3) 3. However, at intermediate and very low ionic strengths, the two procedures produced considerably different activity coefficients.

Chaiko, D. J.; Tasker, I. R.; Fredrickson, D. R.; Difilippo, A. A.; Smidt, S. M.; Vandegrift, G. F.

57

Hydrodynamic and electro-osmotic studies of some aqueous nitrate salt solutions through a porous membrane  

NASA Astrophysics Data System (ADS)

The authors have taken measurements on hydrodynamic and electro- osmotic permeation of water and aqueous salt solutions of ?, ?, and ? in the concentration range ? M to ? M, across pyrex-sintered glass membrane (G-3). The data obtained were used to ascertain the form of transport equation using the theory of non-equilibrium thermodynamics. Phenomenological coefficients, average pore radius, number of pores, and membrane constant have been evaluated. Zeta potential values have been evaluated to characterize the electrical nature of the membrane-permeant interface.

Kumar, Manoj; Ram, Bali

2013-12-01

58

Kinetics and spectroscopy of the NO/sub 3/ radical in aqueous ceric nitrate-nitric acid solutions  

SciTech Connect

A pulsed laser photolysis-long-path absorption apparatus has been employed to investigate the kinetics and spectroscopy of the NO/sub 3/ radical in aqueous nitric acid solution. NO/sub 3/ was prepared by photolysis of cerium ammonium nitrate, Ce(N-H/sub 4/)/sub 2/(NO/sub 3/)/sub 6/. Much lower NO/sub 3/ concentrations were employed than in all previous work on this well-studied photochemical system. Important new findings are (1) the NO/sub 3/(aq) extinction coefficient is considerably larger than previously thought, (2) the appearance of NO/sub 3/ following absorption of a laser photon occurs on a time scale that is fast compared to our 50-ns time resolution, and (3) low concentrations of NO/sub 3/ and other reactive species result in background NO/sub 3/ decay rates which are about an order of magnitude slower than any reported previously. New rate data are reported for the reaction of NO/sub 3/ with Ce(III) and for the reaction SO/sub 4//sup -/ + NO/sub 3//sup -/ ..-->.. NO/sub 3/ + SO/sub 4//sup 2 -/.

Wine, P.H.; Mauldin, R.L. III; Thorn, R.P.

1988-03-10

59

Kinetics of extraction of uranyl nitrate from aqueous electrolyte solutions with a composite material based on polymer-supported trialkylamine at various temperatures  

Microsoft Academic Search

Kinetics of extraction of uranyl nitrate from aqueous electrolyte solutions with a composite material (CM) based on a polymer-supported\\u000a trialkylamine at T = 293.15–333.15 K is studied. The rate-determining stage of the process is found to be the interfacial diffusion (film kinetics).\\u000a The mass-transfer coefficients are determined, and, from their temperature dependences, the apparent activation energy E\\u000a a is estimated.

A. K. Pyartman; V. V. Lishchuk; V. A. Keskinov

2008-01-01

60

Nitrate and natural organic matter in aqueous solutions irradiated by simulated sunlight: Influence on the degradation of the pesticides dichlorprop and terbutylazine.  

PubMed

By means of simulated sunlight, the influence of natural organic matter (NOM) on the photochemical degradation of halogenated pesticides in the absence and presence of nitrate as a precursor of the highly reactive OH radicals in aqueous solutions and freshwater was investigated. Solutions of dichlorprop or terbutylazine (a) in phosphate-buffered demineralized water containing nitrate and/or NOM and (b) in natural freshwaters were irradiated by a 1000-W Xe short-arc lamp. The collimated beam was filtered using a combination of optical filters (WG 320 and WG 295) to simulate the solar spectrum under summer midday conditions. In the absence of nitrate and NOM, the pesticides were degraded photolytically by simulated sunlight. The degradation rates depended on the absorption spectrum in the UVB range and the quantum yield of the degradation. The photochemical degradation of the pesticides was faster in the presence of nitrate due to the sunlight-induced formation of OH radicals. In the absence of nitrate, low concentrations of NOM of a brownwater lake accelerated the degradation due to the formation of reactive species by NOM. At higher concentrations of NOM, the inner filter effect of NOM lowered the degradation rates. In the presence of 50 mg l-1 nitrate, NOM decreased the degradation rate significantly. In case the natural water samples were used as a matrix for the experiments (nitrate concentrations between 2 mg l-1 and 15 mg l-1, DOC concentrations below 2.3 mg l-1), NOM acted mainly as a radiation filter and as a scavenger of OH radicals. As a consequence, in most freshwater systems, the accelerating effect of NOM by the formation of reactive species is of minor importance compared to the inner filter effect and to radical scavenging. PMID:19005835

Schindelin, A J; Frimmel, F H

2000-01-01

61

Precipitacion de oxalato de plutonio (III) y calcinacion a oxido de plutonio. (Precipitation of plutonium (III) oxalate and calcination to plutonium oxide).  

National Technical Information Service (NTIS)

The plutonium based fuel fabrication requires the conversion of the plutonium nitrate solution from nuclear fuel reprocessing into pure PuO2. The conversion method based on the precipitation of plutonium (III) oxalate and subsequent calcination has been s...

A. Esteban E. H. Orosco P. Cassaniti L. Greco P. Adelfang

1989-01-01

62

The influence of plutonium concentration and solution flow rate on the effective capacity of macroporous anion exchange resin. [Lewatit MP-500-FK; Pu/sup +/  

SciTech Connect

The principal aqueous process used to recover and purify plutonium at the Los Alamos Plutonium Facility is anion exchange in nitric acid. Previous studies with gel-type anion exchange resin have shown an inverse relationship between plutonium concentration in the feed solution and the optimum flow rate for this process. Because gel-type resin has been replaced with macroporous resin at Los Alamos, the relationship between plutonium concentration and solution flow rate was reexamined with the selected Lewatit MP-500-FK resin using solutions of plutonium in nitric acid and in nitric acid with high levels of added nitrate salts. Our results with this resin differ significantly from previous data obtained with gel-type resin. Flow-rate variation from 10 to 80 liters per hour had essentially no effect on the measured quantities of plutonium sorbed by the macroporous resin. However, the effect of plutonium concentration in the feed solutions was pronounced, as feed solutions that contained the highest concentrations of plutonium also produced the highest resin loadings. The most notable effect of high concentrations of dissolved nitrate salts in these solutions was an increased resin capacity for plutonium at low flow rates. 16 refs., 7 figs., 2 tabs.

Marsh, S.F.; Gallegos, T.D.

1987-07-01

63

Method for dissolving delta-phase plutonium  

Microsoft Academic Search

This patent describes a process for dissolving plutonium metal, the process. It comprises: heating a mixture of nitric acid, hydroxylammonium nitrate and potassium fluoride; and immersing the plutonium in the mixture; the nitric acid having a concentration of not more than 2M, the hydroxylammonium nitrate having a concentration of between approximately 0.33 M and 1 M, and the potassium fluoride

Karraker

1992-01-01

64

Applicability of Hydroxylamine Nitrate Reductant in Pulse-Column Contactors.  

National Technical Information Service (NTIS)

Uranium and plutonium separations were made from simulated breeder reactor spent fuel dissolver solution with laboratory-sized pulse column contactors. Hydroxylamine nitrate (HAN) was used for reduction of plutonium (1V). An integrated extraction-partitio...

D. J. Reif

1983-01-01

65

Thermochemical nitrate destruction  

DOEpatents

A method is disclosed for denitrification of nitrates and nitrates present in aqueous waste streams. The method comprises the steps of (1) identifying the concentration nitrates and nitrites present in a waste stream, (2) causing formate to be present in the waste stream, (3) heating the mixture to a predetermined reaction temperature from about 200.degree. C. to about 600.degree. C., and (4) holding the mixture and accumulating products at heated and pressurized conditions for a residence time, thereby resulting in nitrogen and carbon dioxide gas, and hydroxides, and reducing the level of nitrates and nitrites to below drinking water standards.

Cox, John L. (Richland, WA); Hallen, Richard T. (Richland, WA); Lilga, Michael A. (Richland, WA)

1992-01-01

66

Laboratory performance testing of an extruded bitumen containing a surrogate, sodium nitrate-based, low-level aqueous waste  

SciTech Connect

Laboratory results of a comprehensive, regulatory performance test program, utilizing an extruded bitumen and a surrogate, sodium nitrate-based waste, have been compiled at the Oak Ridge National Laboratory (ORNL). Using a 53 millimeter, Werner and Pfleiderer extruder, operated by personnel of WasteChem Corporation of Paramus, New Jersey, laboratory-scale, molded samples of type three, air blown bitumen were prepared for laboratory performance testing. A surrogate, low-level, mixed liquid waste, formulated to represent an actual on-site waste at ORNL, containing about 30 wt % sodium nitrate, in addition to eight heavy metals, cold cesium and strontium was utilized. Samples tested contained three levels of waste loading: that is, forty, fifty and sixty wt % salt. Performance test results include the ninety day ANS 16.1 leach test, with leach indices reported for all cations and anions, in addition to the EP Toxicity test, at all levels of waste loading. Additionally, test results presented also include the unconfined compressive strength and surface morphology utilizing scanning electron microscopy. Data presented include correlations between waste form loading and test results, in addition to their relationship to regulatory performance requirements.

Mattus, A.J.; Kaczmarsky, M.M.

1986-12-15

67

Method for dissolving delta-phase plutonium  

SciTech Connect

This patent describes a process for dissolving plutonium metal, the process. It comprises: heating a mixture of nitric acid, hydroxylammonium nitrate and potassium fluoride; and immersing the plutonium in the mixture; the nitric acid having a concentration of not more than 2M, the hydroxylammonium nitrate having a concentration of between approximately 0.33 M and 1 M, and the potassium fluoride having a concentration between approximately 0.05 M approximately 0.1 M.

Karraker, D.G.

1992-08-04

68

Vapour pressures of saturated aqueous solutions of ammonium iodide, potassium iodide, potassium nitrate, strontium chloride, lithium sulphate, sodium thiosulphate, magnesium nitrate, and uranyl nitrate from T =(278 to 323) K  

Microsoft Academic Search

Vapour pressures of saturated aqueous solutions of NH4I, KI, KNO3, SrCl2, Li2SO4, Na2S2O3, Mg(NO3)2, and UO2(NO3)2were determined in the temperature range (278 to 323) K using an electronic hygrometer with an electrolyte sensor, and compared with literature data. Water activities, osmotic coefficients, and molar enthalpies of vaporization and solution at saturation point were evaluated from the determined vapour pressures.

Alexander Apelblat; Eli Korin

1998-01-01

69

Isothermal decomposition of hydroxylamine and hydroxylamine nitrate in aqueous solutions in the temperature range 80-160 degrees C.  

PubMed

Hydroxylamine (HA) and hydroxylamine nitrate (HAN) have been involved independently in several tragic accidents, which incurred numerous fatalities and injuries. Following these incidents, adiabatic calorimetry and computational chemistry research was conducted on those compounds, suggesting potential reaction pathways of their decomposition, but the mechanism of their unstable behavior, still have not been completely understood. In the present work, isothermal decomposition tests were performed accompanied with HPLC, ion chromatography and UV analyses in the temperature range 80-160 degrees C. Condition-dependent autocatalytic decompositions were demonstrated for HA and HAN, and an intermediate formation has been observed that is most likely responsible for their autocatalytic behavior. These findings corroborate previously reported computational chemistry results. PMID:19027229

Liu, Lijun; Papadaki, Maria; Pontiki, Eleni; Stathi, Panagiota; Rogers, William J; Mannan, M Sam

2009-06-15

70

Laboratory-scale evaluations of alternative plutonium precipitation methods  

SciTech Connect

Plutonium(III), (IV), and (VI) carbonate; plutonium(III) fluoride; plutonium(III) and (IV) oxalate; and plutonium(IV) and (VI) hydroxide precipitation methods were evaluated for conversion of plutonium nitrate anion-exchange eluate to a solid, and compared with the current plutonium peroxide precipitation method used at Rocky Flats. Plutonium(III) and (IV) oxalate, plutonium(III) fluoride, and plutonium(IV) hydroxide precipitations were the most effective of the alternative conversion methods tested because of the larger particle-size formation, faster filtration rates, and the low plutonium loss to the filtrate. These were found to be as efficient as, and in some cases more efficient than, the peroxide method. 18 references, 14 figures, 3 tables.

Martella, L.L.; Saba, M.T.; Campbell, G.K.

1984-02-08

71

Purification of alkali metal nitrates  

DOEpatents

A process is disclosed for removing heavy metal contaminants from impure alkali metal nitrates containing them. The process comprises mixing the impure nitrates with sufficient water to form a concentrated aqueous solution of the impure nitrates, adjusting the pH of the resulting solution to within the range of between about 2 and about 7, adding sufficient reducing agent to react with heavy metal contaminants within said solution, adjusting the pH of the solution containing reducing agent to effect precipitation of heavy metal impurities and separating the solid impurities from the resulting purified aqueous solution of alkali metal nitrates. The resulting purified solution of alkali metal nitrates may be heated to evaporate water therefrom to produce purified molten alkali metal nitrate suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of alkali metal nitrates.

Fiorucci, Louis C. (Hamden, CT); Gregory, Kevin M. (Woodridge, IL)

1985-05-14

72

Purge-assisted headspace solid-phase microextraction combined with gas chromatography/mass spectrometry for the determination of trace nitrated polycyclic aromatic hydrocarbons in aqueous samples.  

PubMed

This study describes a new procedure, namely, purge-assisted headspace solid phase microextraction combined with gas chromatography/negative ion chemical ionization mass spectrometry (PA/HS-SPME-GC/NICI-MS), which is used to determine seven nitrated polycyclic aromatic hydrocarbons (NPAHs) in aqueous samples. High extraction efficiency was obtained with PA/HS-SPME with polydimethylsiloxane (PDMS) fiber coating. A programmable temperature vaporizing (PTV) inlet was used in the desorption process. Selected ion monitoring (SIM) was used for quantitative and qualitative purposes. The linear range of detection of the proposed method was 5-5000 pg/mL with coefficients of determination between 0.995 and 0.999. Limits of detection (LODs) for seven NPAHs were 0.01-0.06 pg/mL. The relative standard deviation was below 12.7% at a concentration of 50 pg/mL. Compared with headspace-solid phase microextraction (HS-SPME), the purge procedure enhanced the extraction efficiency for high boiling point analytes, such as 7-nitrobenz[a]anthracene (7-NBA) and 6-nitrochrysene (6-NC). The proposed method provides a sensitive method for NPAH analysis at the pg/mL level. The application of the proposed method for the determination of trace NPAHs in real samples was investigated by analyzing aqueous samples from rivers. The concentrations of NPAHs detected from the samples ranged from 5.2 to 7.5 pg/mL. This method was applied successfully in the analysis of trace NPAHs in river samples. PMID:23089518

Hung, Cheng-Han; Ho, Hsin-Pin; Lin, Mei-Tzu; Chen, Chung-Yu; Shu, Youn-Yuen; Lee, Maw-Rong

2012-11-23

73

Lithium Ion Aqueous Cells.  

National Technical Information Service (NTIS)

Lithium ion aqueous cells were investigated using lithium intercalating compounds as anodes and cathodes. The aqueous electrolyte consisted of 4 to 5 molar solutions of either lithium perchlorate or lithium nitrate which contained lithium hydroxide in mil...

E. J. Plichta W. K. Behl

1995-01-01

74

Polymerization of Pu(IV) in aqueous nitric acid solutions  

SciTech Connect

The polymerization of Pu(IV) in aqueous nitric acid solutions has been studied spectrophotometrically both to establish the influence of large UO{sub 2}(NO{sub 3}){sub 2} concentrations on the polymerization rates and, more generally, to review the influence of the major parameters on the polymer reaction. Typically, experiments have been performed at 50{sup 0}C and with 0.05 M Pu in nitric acid solutions that vary in acidity from 0.07 to 0.4 M. An induction period usually precedes the polymer growth stage during which time nucleation of primary hydrolysis products occurs. Uranyl nitrate retards the polymerization reaction by approximately 35% in spite of the counteracting influence of the nitrate ions associated with this solute. The rate of polymer formation, expressed as d(percent polymer)/dt, has been shown to depend on the total plutonium concentration in reactions where the Pu(IV) concentration remained constant; and it is therefore suggested that the polymer reaction rate is not first order with respect to the concentration of plutonium as was previously thought. It has been shown further that accurate acid determinations on stock reagents are essential in order to obtain reliable polymerization experiments. Satisfactory procedures for these analyses did not exist, so appropriate modifications to the iodate precipitation methods were developed. The most ideal plutonium reagent material has been shown to be crystalline Pu(IV) nitrate because it can be added directly to acid solutions without the occurrence of unintentional hydrolysis reactions.

Toth, L.M.; Friedman, H.A.; Osborne, M.M.

1980-10-01

75

Removal of americium from aqueous nitrate solutions by sorption onto PC88A-Impregnated macroporous polymeric beads.  

PubMed

The removal of Am (III) ions from aqueous solutions was studied by solid-liquid extraction using indigenously synthesized Extractant Impregnated Macroporous Polymeric Beads (EIMPBs). These beads were prepared by an in situ phase inversion method using polyethersulfone (PES) as base polymer and 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC88A) as an extractant. The synthesized EIMPBs were characterized by FTIR, TGA and SEM techniques. The batch equilibration study using these beads for the uptake of Am (III) was carried out as a function of parameters, like pH, equilibration time, Am (III) concentration, etc. The blank polymeric beads, without PC88A, have shown negligible sorption of Am (III) under the experimental conditions. The experimental data on the sorption behavior of Am (III) on the polymeric beads fitted well in the pseudo-second-order kinetics model. The synthesized polymeric beads exhibited very good sorption capacity for Am (III) at pH 3. The reusability of the beads was also ascertained by repetitive sorption/desorption of Am (III) up to 10 cycles of operation, without any significant change in their sorption characteristics. PMID:24997262

Pathak, S K; Tripathi, S C; Singh, K K; Mahtele, A K; Kumar, Manmohan; Gandhi, P M

2014-08-15

76

LITERATURE REVIEW FOR OXALATE OXIDATION PROCESSES AND PLUTONIUM OXALATE SOLUBILITY  

SciTech Connect

A literature review of oxalate oxidation processes finds that manganese(II)-catalyzed nitric acid oxidation of oxalate in precipitate filtrate is a viable and well-documented process. The process has been operated on the large scale at Savannah River in the past, including oxidation of 20 tons of oxalic acid in F-Canyon. Research data under a variety of conditions show the process to be robust. This process is recommended for oxalate destruction in H-Canyon in the upcoming program to produce feed for the MOX facility. Prevention of plutonium oxalate precipitation in filtrate can be achieved by concentrated nitric acid/ferric nitrate sequestration of oxalate. Organic complexants do not appear practical to sequester plutonium. Testing is proposed to confirm the literature and calculation findings of this review at projected operating conditions for the upcoming campaign. H Canyon plans to commence conversion of plutonium metal to low-fired plutonium oxide in 2012 for eventual use in the Mixed Oxide Fuel (MOX) Facility. The flowsheet includes sequential operations of metal dissolution, ion exchange, elution, oxalate precipitation, filtration, and calcination. All processes beyond dissolution will occur in HB-Line. The filtration step produces an aqueous filtrate that may have as much as 4 M nitric acid and 0.15 M oxalate. The oxalate needs to be removed from the stream to prevent possible downstream precipitation of residual plutonium when the solution is processed in H Canyon. In addition, sending the oxalate to the waste tank farm is undesirable. This report addresses the processing options for destroying the oxalate in existing H Canyon equipment.

Nash, C.

2012-02-03

77

Study of the Hydroxylammonium Nitrate - Isopropyl Ammonium Nitrate Reaction.  

National Technical Information Service (NTIS)

When a balanced mixture of hydroxylammonium nitrate (HAN) and isopropyl ammonium nitrate (IPAN) in aqueous solution at appropriate concentrations is ignited in a high pressure bomb the reaction goes to completion to produce H2O, CO2 and N2. Some intermedi...

J. J. Kaufman W. S. Koski

1980-01-01

78

Review of Major Plutonium Pyrochemical Technology.  

National Technical Information Service (NTIS)

The past twenty years have seen significant growth in the development and application of pyrochemical technology for processing of plutonium. For particular feedstocks and specific applications, non-aqueous high-temperature processes offer key advantages ...

W. S. Moser J. D. Navratil

1983-01-01

79

Nitrate Protocol  

NSDL National Science Digital Library

The purpose of this resource is to measure the nitrate-nitrogen of water. Students will use a nitrate kit to measure the nitrate-nitrogen in the water at their hydrology site. The exact procedure depends on the instructions in the nitrate kit used.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2003-08-01

80

Method for dissolving delta-phase plutonium  

Microsoft Academic Search

A process for dissolving plutonium, and in particular, delta-phase plutonium. The process includes heating a mixture of nitric acid, hydroxylammonium nitrate and potassium fluoride (HAN) to a temperature between 40 and 70 C, then immersing the metal in the mixture. Preferably, the nitric acid has a concentration of not ore than 2M, the HAN approximately 0.66M, and the potassium fluoride

Karraker

1992-01-01

81

Method for dissolving delta-phase plutonium  

Microsoft Academic Search

A process for dissolving plutonium, and in particular, delta-phase plutonium. The process includes heating a mixture of nitric acid, hydroxylammonium nitrate (HAN) and potassium fluoride to a temperature between 40.degree. and 70.degree. C., then immersing the metal in the mixture. Preferably, the nitric acid has a concentration of not more than 2M, the HAN approximately 0.66M, and the potassium fluoride

Karraker; David G

1992-01-01

82

Kinetics of extraction and back extraction of Pr(III) and Nd(III) nitrates from aqueous electrolyte solutions with a composite material based on polymer-supported tri- n -butyl phosphate at various temperatures  

Microsoft Academic Search

Kinetics of extraction and back extraction of Pr(III) and Nd(III) nitrates from aqueous electrolyte solutions with a composite\\u000a material (CM) based on polymer-supported tri-n-butyl phosphate (TBP) at 293.15–333.15 K is studied. The rate-determining stage of the processes is found to be the interfacial\\u000a diffusion (film kinetics). The mass-transfer coefficients are determined, and, from their temperature dependences, the apparent\\u000a activation energy

A. K. Pyartman; V. A. Keskinov; V. V. Lishchuk

2008-01-01

83

Nitrate reduction  

DOEpatents

Nitrates are reduced to nitrogen gas by contacting the nitrates with a metal to reduce the nitrates to nitrites which are then contacted with an amide to produce nitrogen and carbon dioxide or acid anions which can be released to the atmosphere. Minor amounts of metal catalysts can be useful in the reduction of the nitrates to nitrites. Metal salts which are formed can be treated electrochemically to recover the metals.

Dziewinski, Jacek J. (Los Alamos, NM); Marczak, Stanislaw (Los Alamos, NM)

2000-01-01

84

Plutonium aging  

SciTech Connect

The author describes the plutonium aging program at the Los Alamos National Laboratory. The aging of plutonium components in the US nuclear weapons stockpile has become a concern due to several events: the end of the cold war, the cessation of full scale underground nuclear testing as a result of the Comprehensive Test Ban Treaty (CTBT) and the closure of the Rocky Flats Plant--the site where the plutonium components were manufactured. As a result, service lifetimes for nuclear weapons have been lengthened. Dr. Olivas will present a brief primer on the metallurgy of plutonium, and will then describe the technical approach to ascertaining the long-term changes that may be attributable to self-radiation damage. Facilities and experimental techniques which are in use to study aging will be described. Some preliminary results will also be presented.

Olivas, J.D.

1999-03-01

85

Thermal Stability Studies of Candidate Decontamination Agents for Hanford’s Plutonium Finishing Plant Plutonium-Contaminated Gloveboxes  

SciTech Connect

This report provides the results of PNNL's and Fluor's studies of the thermal stabilities of potential wastes arising from decontamination of Hanford's Plutonium Finishing Plant's plutonium contaminated gloveboxes. The candidate wastes arising from the decontamination technologies ceric nitrate/nitric acid, RadPro, Glygel, and Aspigel.

Scheele, Randall D.; Cooper, Thurman D.; Jones, Susan A.; Ewalt, John R.; Compton, James A.; Trent, Donald S.; Edwards, Matthew K.; Kozelisky, Anne E.; Scott, Paul A.; Minette, Michael J.

2005-09-29

86

Plutonium pyrophoricity  

SciTech Connect

A review of the published literature on ignition and burning of plutonium metal was conducted in order to better define the characteristic of pyrophoric plutonium. The major parameter affecting ignition is the surface area/mass ratio of the sample. Based on this parameter, plutonium metal can be classified into four categories: (1) bulk metal, (2) film and foils, (3) chips and turnings, and (4) powder. Other parameters that can alter the ignition of the metal include experimental, chemical, physical, and environmental effects. These effects are reviewed in this report. It was concluded from this review that pyrophoric plutonium can be conservatively defined as: Plutonium metal that will ignite spontaneously in air at a temperature of 150{degrees}C or below in the absence of external heat, shock, or friction. The 150{degrees}C temperature was used to compensate for the self-heating of plutonium metal. For a practical definition of whether any given metal is pyrophoric, all of the factors affecting ignition must be considered.

Stakebake, J.L.

1992-06-02

87

Applicability of hydroxylamine nitrate reductant in pulse-column contactors  

SciTech Connect

Uranium and plutonium separations were made from simulated breeder reactor spent fuel dissolver solution with laboratory-sized pulse column contactors. Hydroxylamine nitrate (HAN) was used for reduction of plutonium (1V). An integrated extraction-partition system, simulating a breeder fuel reprocessing flowsheet, carried out a partial partition of uranium and plutonium in the second contactor. Tests have shown that acceptable coprocessing can be ontained using HAN as a plutonium reductant. Pulse column performance was stable even though gaseous HAN oxidation products were present in the column. Gas evolution rates up to 0.27 cfm/ft/sup 2/ of column cross section were tested and found acceptable.

Reif, D.J.

1983-05-01

88

Recovery of plutonium from plutonium-beryllium neutron sources.  

National Technical Information Service (NTIS)

At the Los Alamos National Laboratory, plutonium-beryllium neutron sources have traditionally been processed for plutonium recovery by precipitating the plutonium as plutonium oxalate, calcining to plutonium dioxide, redissolving the oxide and then precip...

M. J. Palmer

1990-01-01

89

Evaluation of nitrate destruction methods  

SciTech Connect

A wide variety of high nitrate-concentration aqueous mixed [radioactive and Resource Conservation and Recovery Act (RCRA) hazardous] wastes are stored at various US Department of Energy (DOE) facilities. These wastes will ultimately be solidified for final disposal, although the waste acceptance criteria for the final waste form is still being determined. Because the nitrates in the wastes will normally increase the volume or reduce the integrity of all of the waste forms under consideration for final disposal, nitrate destruction before solidification of the waste will generally be beneficial. This report describes and evaluates various technologies that could be used to destroy the nitrates in the stored wastes. This work was funded by the Department of Energy`s Office of Technology Development, through the Chemical/Physical Technology Support Group of the Mixed Waste Integrated Program. All the nitrate destruction technologies will require further development work before a facility could be designed and built to treat the majority of the stored wastes. Several of the technologies have particularly attractive features: the nitrate to ammonia and ceramic (NAC) process produces an insoluble waste form with a significant volume reduction, electrochemical reduction destroys nitrates without any chemical addition, and the hydrothermal process can simultaneously treat nitrates and organics in both acidic and alkaline wastes. These three technologies have been tested using lab-scale equipment and surrogate solutions. At their current state of development, it is not possible to predict which process will be the most beneficial for a particular waste stream.

Taylor, P.A. [Oak Ridge National Lab., TN (United States); Kurath, D.E.; Guenther, R. [Pacific Northwest Lab., Richland, WA (United States)

1993-03-30

90

Dopaminium nitrate  

PubMed Central

The asymmetric unit of the title salt [systematic name: 2-(3,4-di­hydroxy­phen­yl)ethanaminium nitrate], C8H12NO2 +·NO3 ?, contains two independent cations and two independent nitrate anions. The crystal structure consists of discrete nitrate ions stacked in layers parallel to (010). These layers are linked via the dopaminium cations by O—H?O, N—H?O and weak C—H?O hydrogen bonds, forming a three-dimensional supra­molecular network.

Gatfaoui, Sofian; Marouani, Houda; Roisnel, Thierry; Dhaouadi, Hassouna

2014-01-01

91

Speciation of plutonium and other metals under UREX process conditIONS  

SciTech Connect

The extractability of various Pu and Np species into tri-n-butyl phosphate (TBP) was investigated. The concentration effects of aceto-hydroxamic acid, nitric acid and nitrate on the distribution ratio of U, Pu and Np were investigated. The considerable ability of AHA to form complexes with the studied elements even under strong acidic conditions was found. While the difference in the extraction of uranyl in the presence and absence of AHA is minimal, extraction yields of Pu and Np decrease significantly. The UV-Vis-NIR and FT-IR spectroscopic investigations of uranium, plutonium, and neptunium species in the presence and absence of AHA in both aqueous and organic extraction phase were also performed. Spectroscopic analysis showed that the organic phase can contain a substantial amount of metal-hydroxamate species. A solvated ternary complex of uranium UO{sub 2}.AHA.NO{sub 3}.2TBP was observed only after prolonged contact between the aqueous and organic phases, whereas the plutonium hydroxamate species, presumably Pu(AHA){sub x}(NO{sub 3}){sub 4-x}.2TBP, appeared in the organic phase after a four minute extraction. (authors)

Paulenova, Alena; Tkac, Peter [Radiation Center, Oregon State University 100 Radiation Center, Corvallis, OR 97331-5903 (United States); Matteson, Brent S. [Department of Chemistry, Oregon State University 100 Radiation Center, Corvallis, OR 97331-5903 (United States)

2007-07-01

92

Energy transfer between Ln(III) ions in aqueous solutions upon formation of labile binuclear fluoride and nitrate complexes of these ions  

Microsoft Academic Search

The influence of anions on nonradiative electronic energy transfer between lanthanide ions in aqueous solutions is studied.\\u000a The rate constant k\\u000a \\u000a t\\u000a of energy transfer was found to increase by three orders of magnitude upon addition of salts of hydrofluoric acid to the\\u000a solution. This effect is caused by the formation of bridge labile binuclear complexes, an excited energy donor-fluorine

E. B. Sveshnikova; S. S. Dudar’; V. L. Ermolaev

2000-01-01

93

Electrolytic production of uranous nitrate  

SciTech Connect

Efficient production of uranous nitrate is important in nuclear fuel reprocessing because U(IV) acts as a plutonium reductant in solvent extraction and can be coprecipitated with plutonium and/or throium as oxalates during fuel reprocessing. Experimental conditions are described for the efficient electrolytic production of uranous nitrate for use as a reductant in the SRP Purex process. The bench-scale, continuous-flow, electrolysis cell exhibits a current efficiency approaching 100% in combination with high conversion rates of U(VI) to U(IV) in simulated and actual SRP Purex solutions. High current efficiency is achieved with a voltage-controlled mercury-plated platinum electrode and the use of hydrazine as a nitrite scavenger. Conversion of U(VI) to U(IV) proceeds at 100% efficiency. Cathodic gas generation is minimal. The low rate of gas generation permits a long residence time within the cathode, a necessary condition for high conversions on a continuous basis. Design proposals are given for a plant-scale, continuous-flow unit to meet SRP production requirements. Results from the bench-scale tests indicate that an 8-kW unit can supply sufficient uranous nitrate reductant to meet the needs of the Purex process at SRP.

Orebaugh, E.G.; Propst, R.C.

1980-04-01

94

Processing of Non-PFP Plutonium Oxide in Hanford Plants  

SciTech Connect

Processing of non-irradiated plutonium oxide, PuO2, scrap for recovery of plutonium values occurred routinely at Hanford’s Plutonium Finishing Plant (PFP) in glovebox line operations. Plutonium oxide is difficult to dissolve, particularly if it has been high-fired; i.e., calcined to temperatures above about 400°C and much of it was. Dissolution of the PuO2 in the scrap typically was performed in PFP’s Miscellaneous Treatment line using nitric acid (HNO3) containing some source of fluoride ion, F-, such as hydrofluoric acid (HF), sodium fluoride (NaF), or calcium fluoride (CaF2). The HNO3 concentration generally was 6 M or higher whereas the fluoride concentration was ~0.5 M or lower. At higher fluoride concentrations, plutonium fluoride (PuF4) would precipitate, thus limiting the plutonium dissolution. Some plutonium-bearing scrap also contained PuF4 and thus required no added fluoride. Once the plutonium scrap was dissolved, the excess fluoride was complexed with aluminum ion, Al3+, added as aluminum nitrate, Al(NO3)3•9H2O, to limit collateral damage to the process equipment by the corrosive fluoride. Aluminum nitrate also was added in low quantities in processing PuF4.

Jones, Susan A.; Delegard, Calvin H.

2011-03-10

95

Method for dissolving delta-phase plutonium  

DOEpatents

A process for dissolving plutonium, and in particular, delta-phase plutonium. The process includes heating a mixture of nitric acid, hydroxylammonium nitrate (HAN) and potassium fluoride to a temperature between 40.degree. and 70.degree. C., then immersing the metal in the mixture. Preferably, the nitric acid has a concentration of not more than 2M, the HAN approximately 0.66M, and the potassium fluoride 0.1M. Additionally, a small amount of sulfamic acid, such as 0.1M can be added to assure stability of the HAN in the presence of nitric acid. The oxide layer that forms on plutonium metal may be removed with a non-oxidizing acid as a pre-treatment step.

Karraker, David G. (1600 Sherwood Pl., SE., Aiken, SC 29801)

1992-01-01

96

Method for aqueous radioactive waste treatment  

DOEpatents

Plutonium, strontium, and cesium found in aqueous waste solutions resulting from nuclear fuel processing are removed by contacting the waste solutions with synthetic zeolite incorporating up to about 5 wt % titanium as sodium titanate in an ion exchange system. More than 99.9% of the plutonium, strontium, and cesium are removed from the waste solutions. 3 figures.

Bray, L.A.; Burger, L.L.

1994-03-29

97

Regioisomer characterization of triacylglycerols by non-aqueous reversed-phase liquid chromatography/electrospray ionization mass spectrometry using silver nitrate as a postcolumn reagent.  

PubMed

Triacylglycerols (TAGs) provide a challenge for mass spectrometry (MS) analysis because of their complexity. In particular, for dietary, nutritional and metabolic purposes, the positional placement of fatty acids on the glycerol backbone of TAGs is a crucial aspect. To solve this problem, we have investigated the TAGs' fragmentation patterns using an ion trap mass spectrometer. A series of pure regioisomeric pairs of TAGs (POP/PPO, POO/OPO and OSO/SOO) were cationized by Ag(+) after their separation by non-aqueous reversed-phase liquid chromatography (NARP-LC) before MS to improve MS sensitivity. Electrospray ionization-MS (ESI-MS) conditions were optimized in order to produce characteristic [M + Ag + AgNO(3)](+) ions from each TAG, which were then fragmented to produce MS/MS spectra and then fragmented further to produce up to MS(5) spectra. The observation of ions produced by LC-MS(5) of on-line Ag(+)-cationized TAG provided unambiguous information on the fatty acid distribution on the glycerol backbone. These strategies of MS to MS(5) experiments were applied to identify components and to determine the regiospecificity of TAG within a complex mixture of lipids in natural oils. PMID:20049691

Lévêque, Nathalie L; Héron, Sylvie; Tchapla, Alain

2010-03-01

98

Thermodynamics of ionization of water at temperatures 278.15 ???T \\/ K ??? 393.15 and at the pressure p = 0.35 MPa: apparent molar volumes and apparent molar heat capacities of aqueous solutions of potassium and sodium nitrates and nitric acid  

Microsoft Academic Search

The apparent molar volumes V?and apparent molar heat capacitiesCp, ? of aqueous solutions of potassium and sodium nitrate and of nitric acid have been determined over the temperature range 278.15 ?T\\/K? 393.15 and molality range 0.015 ?m\\/ (mol · kg?1) ? 0.5 at the pressure p= 0.35 MPa. Densities of these solutions were measured using a vibrating-tube densimeter (DMA 512,

B. A. Patterson; E. M. Woolley

2002-01-01

99

Base Case Pu-Nitrate to Pu-Oxide Conversion Plant.  

National Technical Information Service (NTIS)

This paper explains that the plutonium recovered in the course of reprocessing spent fuel is obtained in the form of plutonium nitrate, whereas PuO sub 2 is required for the fabrication of fuel rods. The reference conversion plant described in the paper c...

1978-01-01

100

Preparation and Properties of Nitrate-Deficient Gadolinium Nitrate Solutions  

SciTech Connect

Because of the high neutron absorption cross sections of some gadolinium isotopes, gadolinium salts in solution are used to control nuclear reactivity in aqueous systems. The present studies concern the preparation and analysis of nitrate-deficient solutions, the effect of time and gamma radiation on their stability, and the determination of the solubility of gadolinium hydroxide in H2O and D2O.

Baumann, E.W.

2001-03-15

101

21 CFR 181.33 - Sodium nitrate and potassium nitrate.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Sodium nitrate and potassium nitrate. 181.33 Section 181.33 Food...Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are subject to prior sanctions...

2010-01-01

102

21 CFR 181.33 - Sodium nitrate and potassium nitrate.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Sodium nitrate and potassium nitrate. 181.33 Section 181.33 Food...Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are subject to prior sanctions...

2009-04-01

103

21 CFR 181.33 - Sodium nitrate and potassium nitrate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Sodium nitrate and potassium nitrate. 181.33 Section 181.33 Food...Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are subject to prior sanctions...

2013-04-01

104

Properties of plutonium.  

National Technical Information Service (NTIS)

Plutonium has unique chemical and physical properties. Its uniqueness in use has led to rare publications in Korea. This report covers physical aspects of phase change of metal plutonium, mechanical properties, thermal conductivity, etc, chemical aspects ...

H. K. Yoon H. T. Kim J. S. Ahn J. S. Ahn K. S. Min

1996-01-01

105

Plutonium Immobilization Puck Handling  

SciTech Connect

The Plutonium Immobilization Project (PIP) will immobilize excess plutonium and store the plutonium in a high level waste radiation field. To accomplish these goals, the PIP will process various forms of plutonium into plutonium oxide, mix the oxide powder with ceramic precursors, press the mixture into pucks, sinter the pucks into a ceramic puck, load the pucks into metal cans, seal the cans, load the cans into magazines, and load the magazines into a Defense Waste Processing Facility (DPWF) canister. These canisters will be sent to the DWPF, an existing Savannah River Site (SRS) facility, where molten high level waste glass will be poured into the canisters encapsulating the ceramic pucks. Due to the plutonium radiation, remote equipment will perform these operations in a contained environment. The Plutonium Immobilization Project is in the early design stages and the facility will begin operation in 2005. This paper will discuss the Plutonium Immobilization puck handling conceptual design and the puck handling equipment testing.

Kriikku, E.

1999-01-26

106

Dehydration of plutonium or neptunium trichloride hydrate  

DOEpatents

A process is described for preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride.

Foropoulos, J. Jr.; Avens, L.R.; Trujillo, E.A.

1992-03-24

107

Dissolution of Plutonium Metal Using a HAN Process  

Microsoft Academic Search

Thermal stability tests were conducted with a nitric acid (HNO3)\\/hydroxylammonium nitrate (HAN)\\/potassium fluoride (KF) solution. The solution has great potential for use in plutonium dissolution because of the small quantity of hydrogen and other offgases produced. Tests were carried out in a Reactive Systems Screening Tool (RSST). The RSST is a calorimeter equipped with temperature and pressure probes as well

2004-01-01

108

Evaluation of the Guided Wave Model 200 Scanning Spectrophotometer for plutonium (VI) determination  

SciTech Connect

We measured the plutonium(VI) in 2M HNO{sub 3} using a Model 200 Guided Wave Scanning Spectrophotometer. In evaluating this instrument for use with the plutonium peak at 831 nm, we determined its precision, stability, and resolution. Chloride and other anions that can strongly complex plutonium must be removed before assay. Plutonium solutions that are free of these anions are diluted with 2M HNO{sub 3} and distributed into calibrated 50-mL volumetric flasks for analysis. The plutonium is oxidized by addition of ceric ammonium nitrate, diluted to 50 mL, and the net peak absorbance at 831 nm measured. The Guided Wave instrument does not completely resolve the plutonium(VI) peak at 831 nm. Poor resolution of the peak results in a lower apparent molar absorptivity (less sensitivity) and diminished compliance with Beer's Law, requiring higher order fits for calibration data. Also small changes in measurements caused by spectral drift of the instrument do not significantly limit its use on this system. Precisions of 0.07% relative for absorbance measurements enable us to quantitate changes resulting from temperature and nitric acid concentration. Absorbances from standards are used to generate a quadratic fit of the calibration data. We then use the quadratic coefficients combined with sample absorbances to calculate the plutonium content of samples. Our calibration data have precisions of 0.15% relative. Compared with coulometric results, assay recoveries are 100.0% with a relative standard deviation of 0.2% for samples (both oxides and nitrates). Once system variables for the chemistry are controlled, the instrument can successfully measure total plutonium in samples. We discuss some system parameters, including nitric acid concentration and temperature at varying plutonium concentrations. Finally, we describe a procedure to assay plutonium content in plutonium oxide and plutonium nitrate solutions. 10 refs., 5 figs., 5 tabs.

Walker, L.F.; Temer, D.J.; Lujan, E.

1991-04-01

109

History and stabilization of the Plutonium Finishing Plant (PFP) complex, Hanford Site  

SciTech Connect

The 231-Z Isolation Building or Plutonium Metallurgy Building is located in the Hanford Site`s 200 West Area, approximately 300 yards north of the Plutonium Finishing Plant (PFP) (234-5 Building). When the Hanford Engineer Works (HEW) built it in 1944 to contain the final step for processing plutonium, it was called the Isolation Building. At that time, HEW used a bismuth phosphate radiochemical separations process to make `AT solution,` which was then dried and shipped to Los Alamos, New Mexico. (AT solution is a code name used during World War II for the final HEW product.) The process was carried out first in T Plant and the 224-T Bulk Reduction Building and B Plant and the 224-B Bulk Reduction Building. The 224-T and -B processes produced a concentrated plutonium nitrate stream, which then was sent in 8-gallon batches to the 231-Z Building for final purification. In the 231-Z Building, the plutonium nitrate solution underwent peroxide `strikes` (additions of hydrogen peroxide to further separate the plutonium from its carrier solutions), to form the AT solution. The AT solution was dried and shipped to the Los Alamos Site, where it was made into metallic plutonium and then into weapons hemispheres.` The 231-Z Building began `hot` operations (operations using radioactive materials) with regular runs of plutonium nitrate on January 16, 1945.

Gerber, M.S., Fluor Daniel Hanford

1997-02-18

110

Determination of plutonium mass by passive neutron assay in input and output samples of MOX pilot conversion plant.  

National Technical Information Service (NTIS)

Neutron measurements were carried out with two different neutron counters on plutonium nitrate solutions and MOX (mixed oxide) powders, respectively input and output samples from the UMCP conversion facility (four glove box process) at the ENEA-EUREX plan...

M. Aparo P. Zeppa V. Pagliai F. Troiani A. Prosdocimi

1989-01-01

111

Review of major plutonium pyrochemical technology  

SciTech Connect

The past twenty years have seen significant growth in the development and application of pyrochemical technology for processing of plutonium. For particular feedstocks and specific applications, non-aqueous high-temperature processes offer key advantages over conventional hydrometallurgical systems. Major processes in use today include: (1) direct oxide reduction for conversion of PuO/sub 2/ to metal, (2) molten salt extraction for americium removal from plutonium, (3) molten salt electrorefining for Pu purification, and (4) hydriding to remove plutonium from host substrates. This paper reviews current major pyrochemical processes from the classical calcination-hydrofluorination-bomb reduction sequence through new techniques under development. Each process is presented and brief descriptions of production equipment are given. 47 references, 5 figures.

Moser, W.S.; Navratil, J.D.

1983-01-01

112

Neptunium and plutonium valence adjustment in enriched uranium processing  

Microsoft Academic Search

In initial operation of a new flowsheet for recovery of highly irradiated enriched uranium by solvent extraction with 7.5 vol percent tri-n-butyl phosphate, valence adjustment of plutonium and neptunium with ferrous sulfamate was ineffective; plutonium was not rejected as desired, and neptunium was partially lost to waste. Laboratory studies demonstrated that ferrous sulfamate, added to both the aqueous feed solution

M. C. Thompson; G. A. Burney; M. L. Hyder

1976-01-01

113

Methyl Cellulose Nitrate.  

National Technical Information Service (NTIS)

Methyl cellulose nitrate was prepared by nitration of methyl cellulose with 98% nitric acid dissolved in methylene chloride and, in 98% nitric acid without a solvent. With both procedures nitration is apparently complete within fifteen minutes. The hetero...

J. Bobinski Y. P. Carignan

1967-01-01

114

Plutonium recovery at the Los Alamos Scientific Laboratory  

SciTech Connect

Research programs have led to the adoption of procedures for all phases of plutonium recovery and purification. This report discusses some of the many procedures required to recover and purify the plutonium contained in the residues generated by LASL research, process development, and production activities. The report also discusses general plant facilities, the liquid and gaseous effluents, and solid waste management practices at the New Plutonium Facility, TA-55. Many of the processes or operations are merely steps in preparing the feed for one of the purification systems. For example, the plutonium is currently removed from noncombustibles in the pickling operation with an HNO/sub 3/ leach. The HNO/sub 3/ leach solution is the product of this operation and is sent to one of the nitrate anion-exchange systems for concentration and purification.

Christensen, E.L.

1980-06-01

115

Solubility of plutonium and uranium in alkaline salt solutions  

SciTech Connect

The solubility of plutonium and uranium in alkaline salt solutions, which will be processed in the In-Tank Precipitation (ITP) process, was investigated to screen for significant factors and interactions among the factors comprising the salt solutions. The factors included in the study were hydroxide, nitrate, nitrite, aluminate, sulfate, carbonate, and temperature. Over the range of factor concentrations studied, the level of hydroxide in the solution is not sufficient alone to predict the resulting concentration of plutonium and uranium in the solution. Other constituents of the salt solution play an important role in determining the amount of plutonium and uranium in solution. Statistical models predicting the plutonium and uranium concentrations over the range of salt solutions investigated are provided.

Hobbs, D.T.; Edwards, T.B.; Fleischman, S.D.

1993-02-12

116

Corrosion-electrochemical properties of the anodic oxide films formed on aluminum in a chloride-nitrate melt in a 0.5 M Aqueous NaCl solution  

NASA Astrophysics Data System (ADS)

The corrosion-electrochemical behavior of aluminum is studied in a chloride-nitrate melt containing 50 wt % eutectic mixture of cesium and sodium chlorides and 50 wt % sodium nitrate in the temperature range 790-900 K in an argon atmosphere.

Elshina, L. A.; Malkov, V. B.; Kudyakov, V. Ya.; Gnedenkov, S. V.; Sinebryukhov, S. L.; Egorkin, V. S.; Mashtalyar, D. V.

2014-02-01

117

Review of major plutonium pyrochemical technology  

Microsoft Academic Search

The past twenty years have seen significant growth in the development and application of pyrochemical technology for processing of plutonium. For particular feedstocks and specific applications, non-aqueous high-temperature processes offer key advantages over conventional hydrometallurgical systems. Major processes in use today include: (1) direct oxide reduction for conversion of PuOâ to metal, (2) molten salt extraction for americium removal from

W. S. Moser; J. D. Navratil

1983-01-01

118

Method for improved decomposition of metal nitrate solutions  

DOEpatents

A method for co-conversion of aqueous solutions of one or more heavy metal nitrates is described, wherein thermal decomposition within a temperature range of about 300 to 800/sup 0/C is carried out in the presence of about 50 to 500% molar concentration of ammonium nitrate to total metal.

Haas, P.A.; Stines, W.B.

1981-01-21

119

Structure of Hydroxylammonium Nitrate (HAN) and the Deuterium Homolog,  

National Technical Information Service (NTIS)

Hydroxylammonium nitrate (HAN) is an oxidizer and a chemical propellant when it is combined with an alkylammonium nitrate fuel in an aqueous solution (Klein, 1985). HAN dissolves in water in a stoichiometry up to about six HAN molecules to one H2O molecul...

A. L. Rheingold J. T. Cronin T. B. Brill F. K. Ross

1987-01-01

120

Photochemical reduction of uranyl nitrate  

SciTech Connect

The photochemical reduction of uranyl nitrate solutions to tetravalent uranium was investigated as a means of producing uranium dioxide feed for the saltless direct oxide reduction (SDOR) process. At high uranium concentrations, reoxidation of U{sup +4} occurs rapidly. The kinetics of the nitric oxidation of tetravalent uranium depend on the concentrations of hydrogen ion, nitrate ion, nitrous acid, and tetravalent uranium in the same manner as was reported elsewhere for the nitrate oxidation of PU{sup +3}. Reaction rate data were successfully correlated with a mechanism in which nitrogen dioxide is the reactive intermediate. Addition of a nitrous acid scavenger suppresses the reoxidation reaction. An immersion reactor employing a mercury vapor lamp gave reduction times fast enough for routine production usage. Precipitation techniques for conversion of aqueous U(NO{sub 3}){sub 4} to hydrous UO{sub 2} were evaluated. Prolonged dewatering times tended to make the process time consuming. Use of 3- to 4-M aqueous NaOH gave the best dewatering times observed. Reoxidation of the UO{sub 2} by water of hydration was encountered, which required the drying process to be carried out under a reducing atmosphere.

Duerksen, W.K.

1993-10-20

121

Redox speciation of plutonium  

Microsoft Academic Search

Knowledge of the oxidation state distribution of plutonium in natural waters is necessary in modeling its behavior in environmental systems. The redox speciation of plutonium is complicated by such effects as hydrolysis, complexation, disproportionation, solubility, and redox interchange reactions. The insolubility of Pu(OH)4 is often the limiting factor of the net solubility of plutonium in oxic natural waters where Pu(V)O

G. R. Choppin; A. H. Bond; P. M. Hromadka

1997-01-01

122

Extraction of REE(III) Nitrates with Polymer-Supported Trialkylmethylammonium Nitrate  

Microsoft Academic Search

Extraction of La, Ce, Pr, Nd, Sm, and Y(III) nitrates with polymer-supported trialkylmethylammonium nitrate (Aliquat-336) in the presence 1-5 M NaNO3 in the aqueous phase is studied. The extraction isotherms are described taking into account formation of (R4N)2[Ln(NO3)5] in the extractant phase. The extraction constants decrease from La to Sm. The extraction constant of Y(III) is considerably lower than those

A. K. Pyartman; V. A. Keskinov; M. A. Mikhailenko; N. V. Nikitin; V. V. Lishchuk

2004-01-01

123

Trawsfynydd Plutonium Estimate  

SciTech Connect

Report serves to document an estimate of the cumulative plutonium production of the Trawsfynydd Unit II reactor (Traws II) over its operating life made using the Graphite Isotope Ratio Method (GIRM). The estimate of the plutonium production in Traws II provided in this report has been generated under blind conditions. In other words, the estimate ofthe Traws II plutonium production has been generated without the knowledge of the plutonium production declared by the reactor operator (Nuclear Electric). The objective of this report is to demonstrate that the GIRM can be employed to serve as an accurate tool to verify weapons materials production declarations.

Reid, Bruce D.; Gerlach, David C.; Heasler, Patrick G.; Livingston, J.

2009-11-20

124

F25 IMPROVEMENTS IN XRF SPECIMEN PREPARATION USING THE DRIED RESIDUE METHOD: GALLIUM IN PLUTONIUM  

Microsoft Academic Search

The concentration of gallium in plutonium metal is critical in manufacturing nuclear weapons, and XRF is a useful method for quantifying the gallium content. A dried residue specimen preparation approach was developed recently to quantify gallium in plutonium metal.1-3 Using this method solids are analyzed, which is safer than the established process of handling radioactive aqueous solutions. The specimen preparation

Christopher G. Worley; Lisa P. Colletti

2003-01-01

125

Plutonium Finishing Plant (PFP) Final Safety Analysis Report (FSAR) [SEC 1 THRU 11  

SciTech Connect

The Plutonium Finishing Plant (PFP) is located on the US Department of Energy (DOE) Hanford Site in south central Washington State. The DOE Richland Operations (DOE-RL) Project Hanford Management Contract (PHMC) is with Fluor Hanford Inc. (FH). Westinghouse Safety Management Systems (WSMS) provides management support to the PFP facility. Since 1991, the mission of the PFP has changed from plutonium material processing to preparation for decontamination and decommissioning (D and D). The PFP is in transition between its previous mission and the proposed D and D mission. The objective of the transition is to place the facility into a stable state for long-term storage of plutonium materials before final disposition of the facility. Accordingly, this update of the Final Safety Analysis Report (FSAR) reflects the current status of the buildings, equipment, and operations during this transition. The primary product of the PFP was plutonium metal in the form of 2.2-kg, cylindrical ingots called buttoms. Plutonium nitrate was one of several chemical compounds containing plutonium that were produced as an intermediate processing product. Plutonium recovery was performed at the Plutonium Reclamation Facility (PRF) and plutonium conversion (from a nitrate form to a metal form) was performed at the Remote Mechanical C (RMC) Line as the primary processes. Plutonium oxide was also produced at the Remote Mechanical A (RMA) Line. Plutonium processed at the PFP contained both weapons-grade and fuels-grade plutonium materials. The capability existed to process both weapons-grade and fuels-grade material through the PRF and only weapons-grade material through the RMC Line although fuels-grade material was processed through the line before 1984. Amounts of these materials exist in storage throughout the facility in various residual forms left from previous years of operations.

ULLAH, M K

2001-02-26

126

Modelling photochemical NOX production and nitrate loss in the upper snowpack of Antarctica  

Microsoft Academic Search

Experimental observations have shown photochemical production in the upper layers of firn. We use a modeling approach for Antarctica in summer, calculating the actinic flux in snowpack, and estimating NOX production from nitrate photolysis. Assuming nitrate photolysis is about as efficient for ice as for aqueous solution, and that all nitrate in the ice is available for photolysis, we find

Eric W. Wolff; Anna E. Jones; Timothy J. Martin; Thomas C. Grenfell

2002-01-01

127

Electrodeposition of Plutonium  

SciTech Connect

Equipment for electrolytic deposition of plutonium from molten salt solutions was designed and built and was tested with cerium as a stand-in for plutonium. The electrolysis cell is a graphite crucible that serves as the anode; the cathode is a molybdenum rod. This paper discusses results of that test.

Kelley, H.M.

2002-10-30

128

Plutonium oxide dissolution.  

National Technical Information Service (NTIS)

Several processing options for dissolving plutonium oxide (PuO(sub 2)) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuO(sub 2) typically generated by burning plutonium metal and PuO(sub 2) pro...

J. H. Gray

1992-01-01

129

Lithium metal reduction of plutonium oxide to produce plutonium metal.  

National Technical Information Service (NTIS)

A method is described for the chemical reduction of plutonium oxides to plutonium metal by the use of pure lithium metal. Lithium metal is used to reduce plutonium oxide to alpha 5 plutonium metal (alpha-Pu). The lithium oxide by-product is reclaimed by s...

M. S. Coops

1991-01-01

130

Lithium metal reduction of plutonium oxide to produce plutonium metal  

Microsoft Academic Search

This patent describes a method for production of plutonium metal from plutonium oxide by metallic lithium reduction, with regeneration of lithium reactant. It comprises: reacting the plutonium oxide with metallic lithium; oxides and unreacted lithium; subliming the product lithium oxide and unreacted lithium from unreacted plutonium oxide with high heat and low pressure; recapturing the product lithium oxides; reacting the

Coops

1992-01-01

131

Lithium metal reduction of plutonium oxide to produce plutonium metal  

Microsoft Academic Search

A method is described for the chemical reduction of plutonium oxides to plutonium metal by the use of pure lithium metal. Lithium metal is used to reduce plutonium oxide to alpha plutonium metal (alpha-Pu). The lithium oxide by-product is reclaimed by sublimation and converted to the chloride salt, and after electrolysis, is removed as lithium metal. Zinc may be used

Coops; Melvin S

1992-01-01

132

31. VIEW OF A WORKER HOLDING A PLUTONIUM 'BUTTON.' PLUTONIUM, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. VIEW OF A WORKER HOLDING A PLUTONIUM 'BUTTON.' PLUTONIUM, A MAN-MADE SUBSTANCE, WAS RARE. SCRAPS RESULTING FROM PRODUCTION AND PLUTONIUM RECOVERED FROM RETIRED NUCLEAR WEAPONS WERE REPROCESSED INTO VALUABLE PURE-PLUTONIUM METAL (9/19/73). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

133

Plutonium roundtable discussion  

SciTech Connect

The roundtable discussion began with remarks by the chairman who pointed out the complicated nature of plutonium chemistry. Judging from the papers presented at this symposium, he noticed a pattern which indicated to him the result of diminished funding for investigation of basic plutonium chemistry and funding focused on certain problem areas. Dr. G.L. silver pointed to plutonium chemists' erroneous use of a simplified summary equation involving the disproportionation of Pu(EV) and their each of appreciation of alpha coefficients. To his appreciation of alpha coefficients. To his charges, Dr. J.T. Bell spoke in defense of the chemists. This discussion was followed by W.W. Schulz's comments on the need for experimental work to determine solubility data for plutonium in its various oxidation states under geologic repository conditions. Discussion then turned to plutonium pyrachemical process with Dana C. Christensen as the main speaker. This paper presents edited versions of participants' written version. (ATT)

Penneman, R.A.

1982-01-01

134

THE RADIOLOGICAL PHYSICS OF PLUTONIUM  

Microsoft Academic Search

Plutonium metal processing operations were developed with the ; utilization of equipment and methods to provide containment for contamination ; control, shields for radiation exposure control, and limitations on plutonium ; mass, concentration, and solution volume for criticality control. Containment of ; plutonium materials in glove boxes and hoods prevents the internal body ; deposition of plutonium radionuclides. The long

Unruh

1962-01-01

135

Plutonium radiation surrogate  

DOEpatents

A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

Frank, Michael I. (Dublin, CA)

2010-02-02

136

Mechanisms of nitrate tolerance  

Microsoft Academic Search

There is now little dispute that clinical tolerance of organic nitrates occurs, particularly when these drugs are used by themselves to treat patients with stable angina pectoris and congestive heart failure. Classical hypotheses of nitrate tolerance suggest the phenomenon to result from vascular depletion of critical sulfhydryl groups, which are necessary to bring about vasorelaxation from nitrates. While this mechanism

Ho-Leung Fung; John Anthony Bauer

1994-01-01

137

Low-level detection and quantification of Plutonium(III, IV, V,and VI) using a liquid core waveguide  

SciTech Connect

Understanding the aqueous chemistry of plutonium, in particular in environmental conditions, is often complicated by plutonium's complex redox chemistry. Because plutonium possesses four oxidation states, all of which can coexist in solution, a reliable method for the identification of these oxidation states is needed. The identification of plutonium oxidation states at low levels in aqueous solution is often accomplished through an indirect determination using series of liquid-liquid extraction procedures using oxidation state specific reagents such as HDEHP and TTA. While these methods, coupled with radioactive counting techniques provide superior limits of detection they may influence the plutonium redox equilibrium, are time consuming, waste intensive and costly. Other analytical methods such as mass spectrometry and radioactive counting as stand alone methods provide excellent detection limits but lack the ability to discriminate between the oxidation states of the plutonium ions in solution.

Wilson, Richard E.; Hu, Yung-Jin; Nitsche, Heino

2003-06-28

138

Precipitation Phenomena of Heavy Metal Soaps in Aqueous Solutions. I. Calcium Oleate.  

National Technical Information Service (NTIS)

Aqueous sols of calcium oleate were prepared by mixing solutions of calcium nitrate with solutions of potassium oleate. It was found that above a certain excess concentration of oleate ions for a given concentration of calcium nitrate the turbidity drops ...

E. Matijevic J. Leja R. Nemeth

1966-01-01

139

Plutonium: Requiem or reprieve  

SciTech Connect

Many scientific discoveries have had profound effects on humanity and its future. However, the discovery of fissionable characteristics of a man-made element, plutonium, discovered in 1941 by Glenn Seaborg and associates, has probably had the greatest impact on world affairs. Although about 20 new elements have been synthesized since 1940, element 94 unarguably had the most dramatic impact when it was introduced to the world as the core of the nuclear bomb dropped on Nagasaki. Ever since, large quantities of this element have been produced, and it has had a major role in maintaining peace during the past 50 years. in addition, the rapid spread of nuclear power technology worldwide contributed to major growth in the production of plutonium as a by-product. This article discusses the following issues related to plutonium: plutonium from Nuclear Power Generation; environmental safety and health issues; health effects; safeguards issues; extended storage; disposal options.

Pillay, K.K.S. [Los Alamos National Laboratory, Berkeley, CA (United States)

1996-01-01

140

Plutonium dissolution process  

DOEpatents

A two-step process for dissolving plutonium metal, which two steps can be carried out sequentially or simultaneously. Plutonium metal is exposed to a first mixture containing approximately 1.0M-1.67M sulfamic acid and 0.0025M-0.1M fluoride, the mixture having been heated to a temperature between 45.degree. C. and 70.degree. C. The mixture will dissolve a first portion of the plutonium metal but leave a portion of the plutonium in an oxide residue. Then, a mineral acid and additional fluoride are added to dissolve the residue. Alteratively, nitric acid in a concentration between approximately 0.05M and 0.067M is added to the first mixture to dissolve the residue as it is produced. Hydrogen released during the dissolution process is diluted with nitrogen.

Vest, Michael A. (Oak Park, IL); Fink, Samuel D. (Aiken, SC); Karraker, David G. (Aiken, SC); Moore, Edwin N. (Aiken, SC); Holcomb, H. Perry (North Augusta, SC)

1996-01-01

141

Disposition of separated plutonium  

Microsoft Academic Search

In the immediate term, plutonium, recovered from dismantled nuclear warheads and from civil reprocessing plants, will have to be stored securely, and under international safeguards if possible. In the intermediate term, the principal alternatives for disposition of this plutonium are: irradiation in mixed?oxide (MOX) fuel assemblies in commercial unmodified light?water reactors or in specially adapted light?water reactors capable of operating

Frans Berkhout; Anatoli Diakov; Harold Feiveson; Helen Hunt; Edwin Lyman; Marvin Miller; Frank von Hippel

1993-01-01

142

Plutonium: The disposal decision  

Microsoft Academic Search

Energy`s dual-track disposition strategy was driven by three principal assumptions: (1) Surplus plutonium should not be left indefinitely in storage because it is too easy to reuse it in weapons (the {open_quotes}breakout{close_quotes} scenario) and too vulnerable to theft, particularly in Russia where inventory controls are weak. (2) Given the fact that the world is already awash in civil plutonium (upwards

1997-01-01

143

Evidence for a plasma-membrane-bound nitrate reductase involved in nitrate uptake of Chlorella sorokiniana  

NASA Technical Reports Server (NTRS)

Anti-nitrate-reductase (NR) immunoglobulin-G (IgG) fragments inhibited nitrate uptake into Chlorella cells but had no affect on nitrate uptake. Intact anti-NR serum and preimmune IgG fragments had no affect on nitrate uptake. Membrane-associated NR was detected in plasma-membrane (PM) fractions isolated by aqueous two-phase partitioning. The PM-associated NR was not removed by sonicating PM vesicles in 500 mM NaCl and 1 mM ethylenediaminetetraacetic acid and represented up to 0.8% of the total Chlorella NR activity. The PM NR was solubilized by Triton X-100 and inactivated by Chlorella NR antiserum. Plasma-membrane NR was present in ammonium-grown Chlorella cells that completely lacked soluble NR activity. The subunit sizes of the PM and soluble NRs were 60 and 95 kDa, respectively, as determined by sodium-dodecyl-sulfate electrophoresis and western blotting.

Tischner, R.; Ward, M. R.; Huffaker, R. C.

1989-01-01

144

INTERCOMPARISON OF PLUTONIUM-239 MEASUREMENTS  

EPA Science Inventory

In 1977 the U.S. Environmental Protection Agency distributed calibrated solutions of plutonium-239 to laboratories interested in participating in an intercomparison study of plutonium analysis. Participants were asked to perform a quantitative radioactivity analysis of the soluti...

145

Thermal decomposition of nitrated tributyl phosphate  

Microsoft Academic Search

Extended contact between heated mixtures of tri-n-butyl phosphate (TBP) and aqueous solutions of nitric acid and\\/or heavy metal nitrate salts at elevated temperatures can lead to exothermic reactions of explosive violence. Most solvent extraction operations are conducted at ambient conditions without heating TBP and have been performed safely for decades, but several explosions involving TBP have occurred in the US,

Y. Hou; E. K. Barefield; D. W. Tedder; S. I. Abdel-Khalik

1996-01-01

146

Plutonium Disposition Now!  

SciTech Connect

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

Buckner, M.R.

1995-05-24

147

NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN  

SciTech Connect

Reillex{trademark} HPQ ion exchange resin is used by HB Line to remove plutonium from aqueous streams. Reillex{trademark} HPQ resin currently available from Vertellus Specialties LLC is a chloride ionic form, which can cause stress corrosion cracking in stainless steels. Therefore, HB Line Engineering requested that Savannah River National Laboratory (SRNL) convert resin from chloride form to nitrate form in the Engineering Development Laboratory (EDL). To perform this task, SRNL treated two batches of resin in 2012. The first batch of resin from Reilly Industries Batch 80302MA was initially treated at SRNL in 2001 to remove chloride. This batch of resin, nominally 30 liters, has been stored wet in carboys since that time until being retreated in 2012. The second batch of resin from Batch 23408 consisted of 50 kg of new resin purchased from Vertellus Specialties in 2012. Both batches were treated in a column designed to convert resin using downflow of 1.0 M sodium nitrate solution through the resin bed followed by rinsing with deionized water. Both batches were analyzed for chloride concentration, before and after treatment, using Neutron Activation Analysis (NAA). The resin specification [Werling, 2003] states the total chlorine and chloride concentration shall be less than 250 ppm. The resin condition for measuring this concentration is not specified; however, in service the resin would always be fully wet. Measurements in SRNL showed that changing from oven dry resin to fully wet resin, with liquid in the particle interstices but no supernatant, increases the total weight by a factor of at least three. Therefore, concentration of chlorine or chloride expressed as parts per million (ppm) decreases by a factor of three. Therefore, SRNL recommends measuring chlorine concentration on an oven dry basis, then dividing by three to estimate chloride concentration in the fully wet condition. Chloride concentration in the first batch (No.80302MA) was nearly the same before the current treatment (759 ppm dry) and after treatment (745 ppm dry or {approx}248 ppm wet). Treatment of the second batch of resin (No.23408) was very successful. Chloride concentration decreased from 120,000 ppm dry to an average of 44 ppm dry or {approx}15ppm wet, which easily passes the 250 ppm wet criterion. Per guidance from HB Line Engineering, SRNL blended Batch 80302 resin with Batch P9059 resin which had been treated previously by ResinTech to remove chloride. The chloride concentrations for the two drums of Batch P9059 were 248 ppm dry ({approx}83 ppm wet) {+-}22.8% and 583 ppm dry ({approx}194 ppm wet) {+-} 11.8%. The blended resin was packaged in five gallon buckets.

Steimke, J.; Williams, M.; Steeper, T.; Leishear, R.

2012-05-29

148

Tin promoted palladium catalysts for nitrate removal from drinking water  

Microsoft Academic Search

Hydrogenation of nitrate to nitrogen using Pd\\/Al2O3 catalysts promoted by a second metal offers a promising process for nitrate removal in drinking water treatment. This study was aimed to elucidate the nature and function of promoting tin species in PdSn\\/Al2O3 catalysts obtained in different preparation routes. On one hand, a parent Pd\\/Al2O3 catalyst was doped via impregnation with aqueous solutions

H Berndt; I Mönnich; B Lücke; M Menzel

2001-01-01

149

Cylodextrin Polymer Nitrate  

NASA Technical Reports Server (NTRS)

The development of the use of cyclodextrin nitrates as possible components of insensitive, high-energy energetics is outlined over a time period of 12 years. Four different types of cyclodextrin polymers were synthesized, nitrated, and evaluated regarding their potential use for the military and aerospace community. The synthesis of these novel cyclodextrin polymers and different nitration techniques are shown and the potential of these new materials is discussed.

Kosowski, Bernard; Ruebner, Anja; Statton, Gary; Robitelle, Danielle; Meyers, Curtis

2000-01-01

150

Weapons plutonium: Just can it  

Microsoft Academic Search

The dilemma plaguing the U.S. Energy Department (DOE) in dealing with 50 years of manufacturing nuclear weapons is choosing a way to dispose of surplus warhead plutonium. The Clinton administration pledged in March 1995 to dispose of approximately 200 metric tons of highly enriched uranium and plutonium. It was later disclosed that this included 38.2 tons of plutonium, of which

Lyman

1996-01-01

151

Ignition characteristics of plutonium powder  

Microsoft Academic Search

Two fires occurred recently in a vacuum cleaner used to pick up plutonium powder during brushing of plutonium. The plutonium powder was collected by a conventional canister vacuum cleaner passing directly into the clean bag which was changed daily and sent to Building 771 for recovery. Finely divided metal powder is known to be a potential fire and explosion hazard.

Musgrave

1971-01-01

152

Ignition characteristics of plutonium powder.  

National Technical Information Service (NTIS)

Two fires occurred recently in a vacuum cleaner used to pick up plutonium powder during brushing of plutonium. The plutonium powder was collected by a conventional canister vacuum cleaner passing directly into the clean bag which was changed daily and sen...

L. E. Musgrave

1971-01-01

153

Lithium metal reduction of plutonium oxide to produce plutonium metal  

DOEpatents

A method is described for the chemical reduction of plutonium oxides to plutonium metal by the use of pure lithium metal. Lithium metal is used to reduce plutonium oxide to alpha plutonium metal (alpha-Pu). The lithium oxide by-product is reclaimed by sublimation and converted to the chloride salt, and after electrolysis, is removed as lithium metal. Zinc may be used as a solvent metal to improve thermodynamics of the reduction reaction at lower temperatures. Lithium metal reduction enables plutonium oxide reduction without the production of huge quantities of CaO--CaCl.sub.2 residues normally produced in conventional direct oxide reduction processes.

Coops, Melvin S. (Livermore, CA)

1992-01-01

154

Plutonium 239 Equivalency Calculations  

SciTech Connect

This document provides the basis for converting actual weapons grade plutonium mass to a plutonium equivalency (PuE) mass of Plutonium 239. The conversion can be accomplished by performing calculations utilizing either: (1) Isotopic conversions factors (CF{sub isotope}), or (2) 30-year-old weapons grade conversion factor (CF{sub 30 yr}) Both of these methods are provided in this document. Material mass and isotopic data are needed to calculate PuE using the isotopic conversion factors, which will provide the actual PuE value at the time of calculation. PuE is the summation of the isotopic masses times their associated isotopic conversion factors for plutonium 239. Isotopic conversion factors are calculated by a normalized equation, relative to Plutonium 239, of specific activity (SA) and cumulated dose inhalation affects based on 50-yr committed effective dose equivalent (CEDE). The isotopic conversion factors for converting weapons grade plutonium to PuE are provided in Table-1. The unit for specific activity (SA) is curies per gram (Ci/g) and the isotopic SA values come from reference [1]. The cumulated dose inhalation effect values in units of rem/Ci are based on 50-yr committed effective dose equivalent (CEDE). A person irradiated by gamma radiation outside the body will receive a dose only during the period of irradiation. However, following an intake by inhalation, some radionuclides persist in the body and irradiate the various tissues for many years. There are three groups CEDE data representing lengths of time of 0.5 (D), 50 (W) and 500 (Y) days, which are in reference [2]. The CEDE values in the (W) group demonstrates the highest dose equivalent value; therefore they are used for the calculation.

Wen, J

2011-05-31

155

Pyrochemical processing of plutonium. Technology review report  

SciTech Connect

Non-aqueous processes are now in routine use for direct conversion of plutonium oxide to metal, molten salt extraction of americium, and purification of impure metals by electrorefining. These processes are carried out at elevated temperatures in either refractory metal crucibles or magnesium-oxide ceramics in batch-mode operation. Direct oxide reduction is performed in units up to 700 gram PuO/sub 2/ batch size with molten calcium metal as the reductant and calcium chloride as the reaction flux. Americium metal is removed from plutonium metal by salt extraction with molten magnesium chloride. Electrorefining is used to isolate impurities from molten plutonium by molten salt ion transport in a controlled potential oxidation-reduction cell. Such cells can purify five or more kilograms of impure metal per 5-day electrorefining cycle. The product metal obtained is typically > 99.9% pure, starting from impure feeds. Metal scrap and crucible skulls are recovered by hydriding of the metallic residues and recovered either as impure metal or oxide feeds.

Coops, M.S.; Knighton, J.B.; Mullins, L.J.

1982-09-08

156

Plutonium in Concentrated Solutions  

SciTech Connect

Complex, high ionic strength media are used throughout the plutonium cycle, from its processing and purification in nitric acid, to waste storage and processing in alkaline solutions of concentrated electrolytes, to geologic disposal in brines. Plutonium oxidation/reduction, stability, radiolysis, solution and solid phase chemistry have been studied in such systems. In some cases, predictive models for describing Pu chemistry under such non-ideal conditions have been developed, which are usually based on empirical databases describing specific ion interactions. In Chapter 11, Non-Ideal Systems, studies on the behavior of Pu in various complex media and available model descriptions are reviewed.

Clark, Sue B.; Delegard, Calvin H.

2002-08-01

157

Solid Solutions in the System Ammonium Nitrate-Potassium Nitrate  

Microsoft Academic Search

BY phase work on the system ammonium nitrate-potassium nitrate-water, Janëcke1,2 showed that below 23° C. two types of solid solution can exist: potassium nitrate dissolved in ammonium nitrate (form III) and ammonium nitrate in potassium nitrate (form II). At higher temperatures there is an increasing amount of another phase which is of a different crystalline form from any of the

R. V. Coates; J. M. Crewe

1961-01-01

158

Compatibility of fuel-element cladding materials with gallium-containing uranium and uranium–plutonium oxide fuel  

Microsoft Academic Search

Powders of uranium oxide powder and mixed fuel containing 5 and 20 mass % plutonium and 0.4 and 5 mass % gallium were prepared\\u000a by coprecipitation from nitrate solutions. Pelleted samples for testing were made by cold pressing and sintering. The compatibility\\u000a of uranium oxide fuel and mixed uranium–plutonium fuel, containing 0.4 and 5 mass % gallium, with the zirconium

O. A. Alekseev; F. G. Reshetnikov; V. A. Volkova

2009-01-01

159

Nitrate sequestration by corticolous macrolichens during winter precipitation events.  

PubMed

Nitrogen is an essential nutrient in the biogeochemistry of forested ecosystems. The influence of canopy lichens on the winter biogeochemistry of nitrate in broadleaved deciduous forests is examined and it is hypothesized that nitrate sequestration will not differ between winter precipitation events. Rejection of this hypothesis would mean that meteorological conditions of winter precipitation events have a detectable influence on nitrate sequestration by canopy lichens and nitrate input to the forest floor. Canopy lichens of the genus Parmelia were found to influence winter nitrate stemflow inputs to forest soils differentially. Epiphytic lichens on an individual Carya glabra Mill. (pignut hickory) canopy tree, centrally located within the stand of an open deciduous forest, actively sequestered nitrate leached from the tree's woody frame, lowering aqueous stemflow inputs at the tree base. The quantities of nitrate sequestered by corticolous lichens during the 2 February 1999 mixed-precipitation event were significantly greater than those during all other precipitation events examined. Greater rates of nitrate uptake during the 2 February 1999 event may be attributed to (1) its intermediate rain intensity, which would have soaked the lichen thalli in a nutrient-rich bath, and (2) an air temperature range between -2 degrees C and 8 degrees C that would have increased viscosity and surface tension of stemflow drainage, thereby decreasing stemflow velocity and increasing the contact time of stemflow water on the lichen thalli. Other precipitation events were either too cold to promote metabolic activity by canopy lichens or too warm and intense for an optimal contact time of stemflow with lichen thalli, resulting in lower quantities of nitrate sequestered. Meteorological conditions of winter precipitation events have been documented to influence sequestration of nitrate by corticolous lichens and decrease aqueous stemflow inputs to the forest floor of broadleaved deciduous forests. PMID:12135200

Levia, Delphis F

2002-05-01

160

MODELED WET NITRATE DEPOSITION  

EPA Science Inventory

Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface water bodies. See below regarding decriptions on how original data was produced. These data will be part of futur...

161

Spinach Nitrate Reductase 1  

PubMed Central

Initial velocity studies of immunopurified spinach nitrate reductase have been performed under conditions of controlled ionic strength and pH and in the absence of chloride ions. Increased ionic strength stimulated NADH:ferricyanide reductase and reduced flavin:nitrate reductase activities and inhibited NADH:nitrate reductase, NADH:cytochrome c reductase and reduced methyl viologen:nitrate reductase activities. NADH:dichlorophenolindophenol reductase activity was unaffected by changes in ionic strength. All of the partial activities, expressed in terms of micromole 2 electron transferred per minute per nanomole heme, were faster than the overall full, NADH:nitrate reductase activity indicating that none of the partial activities included the rate limiting step in electron transfer from NADH to nitrate. The pH optimum for NADH:nitrate reductase activity was determined to be 7 while values for the various partial activities ranged from 6.5 to 7.5. Chlorate, bromate, and iodate were determined to be alternate electron acceptors for the reduced enzyme. These results indicate that unlike the enzyme from Chlorella vulgaris, intramolecular electron transfer between reduced heme and Mo is not rate limiting for spinach nitrate reductase.

Barber, Michael J.; Notton, Brian A.

1990-01-01

162

Nitrite and Nitrate Pharmacokinetics.  

National Technical Information Service (NTIS)

Elimination kinetics of nitrite and nitrate in the canine, ovine, and equine were determined. The elimination half-life of nitrite was found to be 30.0, 28.5 and 33.9 minutes in the canine, ovine and equine, respectively; that of nitrate was 44.68, 4.23 a...

N. R. Schneider R. A. Yeary

1975-01-01

163

Non-destructive measurement of solid plutonium waste at Los Alamos National Laboratory  

SciTech Connect

Los Alamos National Laboratory (LANL) is a national defense facility involved in the recovery and processing of plutonium. Wastes and residues are routinely generated here from many stages of plutonium metal fabrication and from pyrochemical and aqueous processing of plutonium scrap. Materials which require measurement include plutonium oxide from burned residues, Pu-bearing salts from production/reduction and metal purification processes, impure plutonium metal, metal reduction slags, ash, undissolved oxide heels, ceramics, and auxiliary implements such as HEPA filters, plastics, and cleaning rags. Nondestructive assays (NDA) of transuranic (TRU) waste from these materials are often troublesome and may pose formidable challenges to the measurement specialist. This document discusses these waste measurement issues at LANL. 25 figs., 2 tabs.

Wachter, J.R. (Los Alamos National Lab., NM (USA))

1989-01-01

164

Atomic spectrum of plutonium  

SciTech Connect

This report contains plutonium wavelengths, energy level classifications, and other spectroscopic data accumulated over the past twenty years at Laboratoire Aime Cotton (LAC) Argonne National Laboratory (ANL), and Lawrence Livermore National Laboratory (LLNL). The primary purpose was term analysis: deriving the energy levels in terms of quantum numbers and electron configurations, and evaluating the Slater-Condon and other parameters from the levels.

Blaise, J.; Fred, M.; Gutmacher, R.G.

1984-08-01

165

Hydride-catalyzed corrosion of plutonium by air: Initiation by plutonium monoxide monohydride  

SciTech Connect

Chemistry and kinetics of air reactions with plutonium monoxide monohydride (PuOH) and with mixtures of the oxide hydride and plutonium metal are defined by results of pressure-volume-temperature (PVT) measurements. Test with specimens prepared by total and partial corrosion of plutonium in 0.05 M sodium chloride solution show that reaction of residual water continues to generate H{sub 2} after liquid water is removed by evacuation. Rapid exposure of PuOH to air at room temperature does not produce a detectable reaction, but similar exposure of a partially corroded metal sample containing Pu and PuOH results in hydride (PuH{sub x})-catalyzed corrosion of the residual Pu. Kinetics of he first-order reaction resulting in formation of the PuH{sub x} catalyst and of the indiscriminate reaction of N{sub 2} and O{sub 2} with plutonium metal are defined. The rate of the catalyzed Pu+air reaction is independent of temperature (E{sub a} = 0), varies as the square of air pressure, and equals 0.78 {+-} 0.03 g Pu/cm{sup 2} min in air at one atmosphere. The absence of pyrophoric behavior for PuOH and differences in the reactivities of PuOH and PuOH + Pu mixtures are attributed to kinetic control by gaseous reaction products. Thermodynamic properties of the oxide hydride are estimated, particle size distributions of corrosion products are presented, and potential hazards associated with products formed by aqueous corrosion of plutonium are discussed.

Allen, T.H.; Haschke, J.M.

1998-06-01

166

Nitrate reduction by metallic iron  

Microsoft Academic Search

Chemical reduction of nitrate by metallic iron (Fe0) was studied as a potential technology to remove nitrate from water. The effects of pH and the iron-to-nitrate ratio on both nitrate reduction rate and percent removal were investigated. Rate constants and the apparent reaction order with respect to nitrate were determined and a mass balance was obtained. Rapid nitrate reduction by

Chin-Pao Huang; Hung-Wen Wang; Pei-Chun Chiu

1998-01-01

167

The vapour pressures of saturated aqueous solutions of sodium chloride, sodium bromide, sodium nitrate, sodium nitrite, potassium iodate, and rubidium chloride at temperatures from 227 K to 323 K  

Microsoft Academic Search

The vapour pressures of saturated aqueous solutions of NaCl, NaBr, NaNO3, NaNO2, KIO3, and RbCl were determined in the temperature rangeT=(278 to 323) K using an electronic hygrometer with an electrolyte sensor and compared with the literature data, which are available only for the first four salts. These vapour pressures serve to evaluate the water activities, osmotic coefficients, and molar

Alexander Apelblat; Eli Korin

1998-01-01

168

Plutonium Finishing Plant. Interim plutonium stabilization engineering study  

SciTech Connect

This report provides the results of an engineering study that evaluated the available technologies for stabilizing the plutonium stored at the Plutonium Finishing Plant located at the hanford Site in southeastern Washington. Further processing of the plutonium may be required to prepare the plutonium for interim (<50 years) storage. Specifically this document provides the current plutonium inventory and characterization, the initial screening process, and the process descriptions and flowsheets of the technologies that passed the initial screening. The conclusions and recommendations also are provided. The information contained in this report will be used to assist in the preparation of the environmental impact statement and to help decision makers determine which is the preferred technology to process the plutonium for interim storage.

Sevigny, G.J.; Gallucci, R.H.; Garrett, S.M.K.; Geeting, J.G.H.; Goheen, R.S.; Molton, P.M.; Templeton, K.J.; Villegas, A.J. [Pacific Northwest Lab., Richland, WA (United States); Nass, R. [Nuclear Fuel Services, Inc. (United States)

1995-08-01

169

CSER 00-003 Criticality Safety Evaluation report for PFP Magnesium Hydroxide Precipitation Process for Plutonium Stabilization Glovebox 3  

SciTech Connect

This Criticality Safety Evaluation Report analyzes the stabilization of plutonium/uranium solutions in Glovebox 3 using the magnesium hydroxide precipitation process at PFP. The process covered are the receipt of diluted plutonium solutions into three precipitation tanks, the precipitation of plutonium from the solution, the filtering of the plutonium precipitate from the solution, the scraping of the precipitate from the filter into boats, and the initial drying of the precipitated slurry on a hot plate. A batch (up to 2.5 kg) is brought into the glovebox as plutonium nitrate, processed, and is then removed in boats for further processing. This CSER establishes limits for the magnesium hydroxide precipitation process in Glovebox 3 to maintain criticality safety while handling fissionable material.

LAN, J.S.

2000-07-13

170

4. VIEW OF PLUTONIUM CANISTER ON CHAINVEYOR. SCRAP PLUTONIUM WAS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW OF PLUTONIUM CANISTER ON CHAINVEYOR. SCRAP PLUTONIUM WAS COLLECTED INTO CANS AT INDIVIDUAL WORKSTATIONS. THE CANS WERE TRANSFERRED VIA THE CHAIN CONVEYOR TO A WORKSTATION IN MODULE C WHERE THE MATERIAL WAS COMPRESSED INTO BRIQUETTES FOR LATER USE. (6/20/93) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

171

Plutonium age dating reloaded  

NASA Astrophysics Data System (ADS)

Although the age determination of plutonium is and has been a pillar of nuclear forensic investigations for many years, additional research in the field of plutonium age dating is still needed and leads to new insights as the present work shows: Plutonium is commonly dated with the help of the 241Pu/241Am chronometer using gamma spectrometry; in fewer cases the 240Pu/236U chronometer has been used. The age dating results of the 239Pu/235U chronometer and the 238Pu/234U chronometer are scarcely applied in addition to the 240Pu/236U chronometer, although their results can be obtained simultaneously from the same mass spectrometric experiments as the age dating result of latter. The reliability of the result can be tested when the results of different chronometers are compared. The 242Pu/238U chronometer is normally not evaluated at all due to its sensitivity to contamination with natural uranium. This apparent 'weakness' that renders the age dating results of the 242Pu/238U chronometer almost useless for nuclear forensic investigations, however turns out to be an advantage looked at from another perspective: the 242Pu/238U chronometer can be utilized as an indicator for uranium contamination of plutonium samples and even help to identify the nature of this contamination. To illustrate this the age dating results of all four Pu/U clocks mentioned above are discussed for one plutonium sample (NBS 946) that shows no signs of uranium contamination and for three additional plutonium samples. In case the 242Pu/238U chronometer results in an older 'age' than the other Pu/U chronometers, contamination with either a small amount of enriched or with natural or depleted uranium is for example possible. If the age dating result of the 239Pu/235U chronometer is also influenced the nature of the contamination can be identified; enriched uranium is in this latter case a likely cause for the missmatch of the age dating results of the Pu/U chronometers.

Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Mayer, Klaus; Prohaska, Thomas

2014-05-01

172

Development of a novel hydroxyl ammonium nitrate based liquid propellant for air-independent propulsion  

Microsoft Academic Search

The focus of this dissertation is the development of an Unmanned Undersea Vehicle (UUV) liquid propellant employing Hydroxyl Ammonium Nitrate (HAN) as the oxidizer. Hydroxyl Ammonium Nitrate is a highly acidic aqueous based liquid oxidizer. Therefore, in order to achieve efficient combustion of a propellant using this oxidizer, the fuel must be highly water soluble and compatible with the oxidizer

Joseph Henry Fontaine

2006-01-01

173

Bioactivation of organic nitrates and the mechanism of nitrate tolerance.  

PubMed

Organic nitrates, such as nitroglycerin, are commonly used in the therapy of cardiovascular disease. Long-term therapy with these drugs, however, results in the rapid development of nitrate tolerance, limiting their hemodynamic and anti-ischemic efficacy. In addition, nitrate tolerance is associated with the expression of potentially deleterious modifications such as increased oxidative stress, endothelial dysfunction, and sympathetic activation. In this review we discuss current concepts regarding the mechanisms of organic nitrate bioactivation, nitrate tolerance, and nitrate-mediated oxidative stress and endothelial dysfunction. We also examine how hydralazine may prevent nitrate tolerance and related endothelial dysfunction. PMID:19130411

Klemenska, Emila; Beresewicz, Andrzej

2009-01-01

174

Extraction of uranyl, La(III), and Y(III) nitrates with a composite solid extractant based on a polymeric support impregnated with trialkylmethylammonium nitrate  

Microsoft Academic Search

Extraction of uranyl, La(III), and Y(III) nitrates from aqueous solutions containing 0–4 M sodium nitrate with a composite\\u000a solid extractant based on a polymeric support impregnated with trialkylmethylammonium nitrate (Aliquat-336) was studied. The\\u000a extraction isotherms were analyzed assuming that uranyl, La(III), and Y(III) nitrates are extracted with the solid extractant\\u000a in the form of complexes (R4N)2[Ln(NO3)5] and (R4N)2[UO2(NO3)4], respectively. The

A. K. Pyartman; V. A. Keskinov; V. V. Lishchuk; A. V. Konstantinova; V. V. Belova

2007-01-01

175

Decomposition of Four Ammonium Nitrate Propellants.  

National Technical Information Service (NTIS)

The biodegradability of four ammonium nitrate propellants, trimethylammonium nitrate (TMAN), isopropylammonium nitrate (IPAN), triethanolammonium nitrate (TEAN), and hydroxylammonium nitrate (HAN) was assessed in batch and continuous cultures under a vari...

D. L. Kaplan D. J. Emerson P. A. Riley A. M. Kaplan

1983-01-01

176

Recovery Studies for Plutonium Machining Oil Coolant.  

National Technical Information Service (NTIS)

Lathe coolant oil, contaminated with plutonium and having a carbon tetrachloride diluent, is generated in plutonium machining areas at Rocky Flats. A research program was initiated to determine the nature of plutonium in this mixture of oil and carbon tet...

J. D. Navratil C. E. Baldwin

1977-01-01

177

Gamma radiation characteristics of plutonium dioxide fuel  

NASA Technical Reports Server (NTRS)

Investigation of plutonium dioxide as an isotopic fuel for Radioisotope Thermoelectric Generators yielded the isotopic composition of production-grade plutonium dioxide fuel, sources of gamma radiation produced by plutonium isotopes, and the gamma flux at the surface.

Gingo, P. J.

1969-01-01

178

Plutonium Air Shipments  

NSDL National Science Digital Library

The Nuclear Control Institute created a web site in response to a proposed standard for the shipment of radioactive materials. This site presents two world maps showing both sea and air routes that are planned or already in use for the shipment of plutonium. A series of papers by NCI-affiliated scientists and observers on the subject of radioactive materials shipments sets out the NCI position against such shipments.

1996-01-01

179

Probing phonons in plutonium  

Microsoft Academic Search

Plutonium (Pu) is well known to have complex and unique physico-chemical properties [1]. Notably, the pure metal exhibits six solid-state phase transformations with large volume expansions and contractions along the way to the liquid state: ' {var_epsilon} liquid. Unalloyed Pu melts at a relatively low temperature 640 C to yield a higher density liquid than that of the solid from

D Farber; T Chiang; M Krisch; F Occelli; A Schwartz; M Wall; R Xu; C Boro

2003-01-01

180

Probing phonons in plutonium  

Microsoft Academic Search

Plutonium (Pu) is well known to have complex and unique physico-chemical properties. Notably, the pure metal exhibits six solid-state phase transformations with large volume expansions and contractions along the way to the liquid state: α â β â γ â δ â δⲠâ {var_epsilon} â liquid. Unalloyed Pu melts at a relatively low temperature â640 C to yield a

Joe Wong; M. Krisch; D. Farber; F. Occelli; A. Schwartz; T. C. Chiang; M. Wall; C. Boro; Ruqing Xu

2010-01-01

181

Proliferation aspects of plutonium recycling  

Microsoft Academic Search

Plutonium recycling offers benefits in an energy perspective of sustainable development, and, moreover it contributes to non-proliferation. Prior to recycling, reactor-grade plutonium from light-water reactors does not lend itself easily to the assembly of explosive nuclear devices; thereafter, practically not at all. Control systems for material security and non-proliferation should identify and adopt several categories of plutonium covering various isotopic

Bruno Pellaud

2002-01-01

182

Manufacturing of Plutonium Tensile Specimens  

SciTech Connect

Details workflow conducted to manufacture high density alpha Plutonium tensile specimens to support Los Alamos National Laboratory's science campaigns. Introduces topics including the metallurgical challenge of Plutonium and the use of high performance super-computing to drive design. Addresses the utilization of Abaqus finite element analysis, programmable computer numerical controlled (CNC) machining, as well as glove box ergonomics and safety in order to design a process that will yield high quality Plutonium tensile specimens.

Knapp, Cameron M [Los Alamos National Laboratory

2012-08-01

183

Burning of hydroxylammonium nitrate  

Microsoft Academic Search

Burning of solid crystalline hydroxylammonium nitrate (HAN) and its water solutions is studied in a constant-pressure bomb\\u000a within the pressure range from 0.1 to 36 MPa. Abnormally high pressure exponents are found to be typical of combustion of\\u000a the crystalline substance, its ?9-mole\\/liter water solution, and a solution containing ethanolamine nitrate as a fuel: for\\u000a pressures below ?10 MPa, the

B. N. Kondrikov; V. É. Annikov; V. Yu. Egorshev; L. T. De Luca

2000-01-01

184

Schleimhautvertraeglichkeitspruefung mit Silbernitrat (Eye Irritation Study with Silver Nitrate).  

National Technical Information Service (NTIS)

Silver nitrate (1% aqueous solution) was applied to one eye of each of 3 rabbits. The animals were observed after 1h, 24h, 3d and 7d. Only lesions of the treated eyes were observed. Conjunctival chemosis and redness were found as well as discharge. In one...

1981-01-01

185

Ceric ammonium nitrate induced grafting of polyacrylamide onto carboxymethyl chitosan  

Microsoft Academic Search

O-Carboxymethyl chitosan (CMCH) was prepared and characterized by FTIR spectroscopy and X-ray diffraction. Grafting of acrylamide (Am) onto CMCH using ceric ammonium nitrate (CAN) as an initiator was carried out under nitrogen atmosphere in aqueous solution. Evidence of grafting was confirmed by comparison of FTIR spectra of CMCH and the grafted copolymer as well as scanning electron micrography (SEM) and

Jigar M. Joshi; Vijay Kumar Sinha

2007-01-01

186

Prolifération et recyclage du plutonium  

NASA Astrophysics Data System (ADS)

Plutonium recycling offers benefits in an energy perspective of sustainable development, and, moreover it contributes to non-proliferation. Prior to recycling, reactor-grade plutonium from light-water reactors does not lend itself easily to the assembly of explosive nuclear devices; thereafter, practically not at all. Control systems for material security and non-proliferation should identify and adopt several categories of plutonium covering various isotopic mixtures associated with different fuel types, in order to better reflect the risks and to better focus their controls. The author proposes the adoption of three categories of plutonium. To cite this article: B. Pellaud, C. R. Physique 3 (2002) 1067-1079.

Pellaud, Bruno

2002-10-01

187

Thermal decomposition hazard evaluation of hydroxylamine nitrate.  

PubMed

Hydroxylamine nitrate (HAN) is an important member of the hydroxylamine family and it is a liquid propellant when combined with alkylammonium nitrate fuel in an aqueous solution. Low concentrations of HAN are used primarily in the nuclear industry as a reductant in nuclear material processing and for decontamination of equipment. Also, HAN has been involved in several incidents because of its instability and autocatalytic decomposition behavior. This paper presents calorimetric measurement for the thermal decomposition of 24 mass% HAN/water. Gas phase enthalpy of formation of HAN is calculated using both semi-empirical methods with MOPAC and high-level quantum chemical methods of Gaussian 03. CHETAH is used to estimate the energy release potential of HAN. A Reactive System Screening Tool (RSST) and an Automatic Pressure Tracking Adiabatic Calorimeter (APTAC) are used to characterize thermal decomposition of HAN and to provide guidance about safe conditions for handling and storing of HAN. PMID:16154263

Wei, Chunyang; Rogers, William J; Mannan, M Sam

2006-03-17

188

THE EXTINGUISHING OF PLUTONIUM FIRES  

Microsoft Academic Search

A fusible ternary eutectic salt mixture of barium, sodium, and potassium ; chlorides was developed as an extinguishant for metallic fissile material fires. ; The powder extinguished fires involving massive and finely divided uranium and ; massive plutonium, but was not successful with fires involving finely divided ; plutonium, combustion continuing under the powder. Tests indicated that a ; fusible

J. Holliday; W. A. Conway

1962-01-01

189

Ceramic matrices for plutonium disposition  

Microsoft Academic Search

One of the major issues related to the expanded use of nuclear power and the development of advanced nuclear fuel cycles is the fate of plutonium and “minor” actinides. In addition, substantial quantities of plutonium and highly enriched uranium from dismantled nuclear weapons now require disposition. There are two basic strategies for the disposition of the actinides: (1) to “burn”

Rodney C. Ewing

2007-01-01

190

Photochemical preparation of plutonium pentafluoride  

DOEpatents

The novel compound plutonium pentafluoride may be prepared by the photodissociation of gaseous plutonium hexafluoride. It is a white solid of low vapor pressure, which consists predominantly of a face-centered cubic structure with a.sub.o =4.2709.+-.0.0005 .ANG..

Rabideau, Sherman W. (Los Alamos, NM); Campbell, George M. (Los Alamos, NM)

1987-01-01

191

Solvent anode for plutonium purification  

SciTech Connect

The purpose of this study is to develop a technique to allow complete oxidation of plutonium from the anode during plutonium electrorefining. This will eliminate the generation of a ''spent'' anode heel which requires further treatment for recovery. Our approach is to employ a solvent metal in the anode to provide a liquid anode pool throughout electrorefining. We use molten salts and metals in ceramic crucibles at 700/sup 0/C. Our goal is to produce plutonium metal at 99.9% purity with oxidation and transfer of more than 98% of the impure plutonium feed metal from the anode into the salt and product phases. We have met these criteria in experiments on the 100 to 1000 g scale. We plan to scale our operations to 4 kg of feed plutonium and to optimize the process parameters.

Bowersox, D.F.; Fife, K.W.; Christensen, D.C.

1986-01-01

192

Aqueous processing of actinides at Savannah River  

SciTech Connect

A number of changes affecting the DP-Complex are having an impact on operations at the Savannah River Site (SRS). In order for SRS to continue as a major contributor within the DP-Complex and remain in position to respond to requests based on new initiatives, programs aimed at redirecting the actinide processing activities have been started. One area undergoing process modifications is F-Canyon, where most of the plutonium feedstocks are processed. Programs already underway that are affecting the dissolution of plutonium materials in canyon dissolvers and the purification of aqueous streams in the second plutonium solvent extraction cycle are discussed. Issues influencing program direction involve environmental concerns, waste minimization, health protection, storage limitations, and material recycle. Each of these issues is discussed in relation to operations in F-Canyon and results based on initial development studies are presented.

Gray, J.H.

1990-01-01

193

Plutonium oxide dissolution  

SciTech Connect

Several processing options for dissolving plutonium oxide (PuO{sub 2}) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuO{sub 2} typically generated by burning plutonium metal and PuO{sub 2} produced during incineration of alpha contaminated waste. At least two processing options remain applicable for dissolving high-fired PuO{sub 2} in canyon dissolvers. The options involve solid solution formation of PuO{sub 2} With uranium oxide (UO{sub 2}) and alloying incinerator ash with aluminum. An oxidative dissolution process involving nitric acid solutions containing a strong oxidizing agent, such as cerium (IV), was neither proven nor rejected. This uncertainty was due to difficulty in regenerating cerium (IV) ions during dissolution. However, recent work on silver-catalyzed dissolution of PuO{sub 2} with persulfate has demonstrated that persulfate ions regenerate silver (II). Use of persulfate to regenerate cerium (IV) or bismuth (V) ions during dissolution of PuO{sub 2} materials may warrant further study.

Gray, J.H.

1992-09-30

194

Plutonium oxide dissolution  

SciTech Connect

Several processing options for dissolving plutonium oxide (PuO[sub 2]) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuO[sub 2] typically generated by burning plutonium metal and PuO[sub 2] produced during incineration of alpha contaminated waste. At least two processing options remain applicable for dissolving high-fired PuO[sub 2] in canyon dissolvers. The options involve solid solution formation of PuO[sub 2] With uranium oxide (UO[sub 2]) and alloying incinerator ash with aluminum. An oxidative dissolution process involving nitric acid solutions containing a strong oxidizing agent, such as cerium (IV), was neither proven nor rejected. This uncertainty was due to difficulty in regenerating cerium (IV) ions during dissolution. However, recent work on silver-catalyzed dissolution of PuO[sub 2] with persulfate has demonstrated that persulfate ions regenerate silver (II). Use of persulfate to regenerate cerium (IV) or bismuth (V) ions during dissolution of PuO[sub 2] materials may warrant further study.

Gray, J.H.

1992-09-30

195

Separating Metallic Beryllium from Plutonium by Selective Dissolution with Ammonium Fluoride  

SciTech Connect

Plutonium metal is stabilized for long-term storage by calcining to produce PuO{sub 2}. However, if beryllium is present, the calcined product may have a high neutron dose rate because of the {sup 9}Be({alpha},n){sup 12}C reaction in the finely divided oxide mixture. (At LLNL, inadvertent calcining of a mixture of {approx}500 g Pu/50 g Be produced a neutron source of {approx}5 R/hr.) Therefore, for health physics reasons, we would like a convenient procedure to remove beryllium from plutonium with high selectivity. Two reagents, sodium hydroxide and ammonium fluoride, were considered for aqueous processing. Each reagent selectively dissolves beryllium, which can be separated from the insoluble plutonium by decanting/filtering operations followed by water washes to remove the excess reagent. The washed plutonium is calcined for storage; the beryllium and wash fractions are solidified for disposal.

Torres, R A

2006-11-29

196

Improved recovery and purification of plutonium at Los Alamos using macroporous anion exchange resin  

SciTech Connect

For almost 30 years, Los Alamos National Laboratory has used anion exchange in nitric acid as the major aqueous process or the recovery and purification of plutonium. One of the few disadvantages of this system is the particularly slow rate at which the anionic nitrato complex of Pu(IV) equilibrates with the resin. The Nuclear Materials Process Technology Group at Los Alamos recently completed an ion exchange development program that focused on improving the slow sorption kinetics that limits this process. A comprehensive investigation of modern anion exchange resins identified porosity and bead size as the properties that most influence plutonium sorption kinetics. Our study found that small beads of macroporous resin produced a dramatic increase in plutonium process efficiency. The Rocky Flats Plant has already adopted this improved ion exchange technology, and it currently is being evaluated for use in other DOE plutonium-processing facilities.

Marsh, S.F.; Mann, M.J. (ed.)

1987-05-01

197

Long term plutonium solubility and speciation studies in a synthetic brine  

SciTech Connect

The rate at which elements can be transported in groundwater systems is governed in part by the solubility of the element in the groundwater. This report documents plutonium solubility experiments in a brine simulant relevant to the Waste Isolation Pilot Plant. Approximately 1 to 2.5 mL of five stock solutions containing single oxidation states of plutonium (Pu(IV)-polymer, Pu{sup 3+}, Pu{sup 4+}, PuO{sub 2}{sup +}, and PuO{sub 2}{sup 2+}) were added to {approximately}75 mL of synthetic H-17 Brine in five reaction vessels. Initial plutonium concentrations ranged from 1.3 {times} l0{sup {minus}4} to 5.l {times} l0{sup {minus}4} M (moles per liter) total plutonium. Because these initial concentrations were far above the plutonium solubility limit in H-17 Brine, plutonium-containing solids precipitated. Aqueous plutonium concentrations were measured over time until steady-state was reached, requiring over 300 days in H-17 Brine.

Nitsche, Heino; Roberts, K.; Xi, Ruihua [Lawrence Berkeley Lab., CA (United States)] [and others

1993-12-31

198

Reverse Osmosis Separation of Radium from Dilute Aqueous Solutions  

Microsoft Academic Search

Porous cellulose acetate membranes obtained from Osmonics Inc. were characterized in terms of pure water permeability constant, solute transport parameter, and mass transfer coefficient with aqueous sodium chloride solution as the reference system. Reverse osmosis separation behavior of radium-226 as nitrate, chloride, and sulfate salts was studied. Reverse osmosis method of removing radium-226 from aqueous solutions has been compared with

K. S. Subramanian; V. S. Sastri

1980-01-01

199

Desferrioxamine Inhibits Protein Tyrosine Nitration: Mechanisms and Implications  

PubMed Central

Tissues are exposed to exogenous and endogenous nitrogen dioxide (•NO2), which is the terminal agent in protein tyrosine nitration. Besides iron chelation, the hydroxamic acid (HA) desferrioxamine (DFO) shows multiple functionalities including nitration inhibition. To investigate mechanisms whereby DFO affects 3-nitrotyrosine (3-NT) formation, we utilized gas phase •NO2 exposures, to limit introduction of other reactive species, and a lung surface model wherein red cell membranes (RCM) were immobilized under a defined aqueous film. When RCM were exposed to •NO2 covered by +/? DFO: (i) DFO inhibited 3-NT formation more effectively than other HA and non-HA chelators; (ii) 3-NT inhibition occurred at very low [DFO] for prolonged times; and (iii) 3-NT formation was iron independent but inhibition required DFO present. DFO poorly reacted with •NO2 compared to ascorbate, assessed via •NO2 reactive absorption and aqueous phase oxidation rates, yet limited 3-NT formation at far lower concentrations. DFO also inhibited nitration under aqueous bulk phase conditions, and inhibited 3-NT generated by active myeloperoxidase “bound” to RCM. Per the above and kinetic analyses suggesting preferential DFO versus •NO2 reaction within membranes, we conclude that DFO inhibits 3-NT formation predominantly by facile repair of the tyrosyl radical intermediate, which prevents •NO2 addition, and thus nitration, and potentially influences biochemical functionalities.

Adgent, Margaret A.; Squadrito, Giuseppe L.; Ballinger, Carol A.; Krzywanski, David M.; Lancaster, Jack R.; Postlethwait, Edward M.

2012-01-01

200

Nitrate uptake and nitrate reduction in synchronous Chlorella  

Microsoft Academic Search

Nitrate uptake was followed continuously in cultures of Chlorella sorokiniana using ionsensitive electrodes. During the lifecycle of the synchronous cell cultures, a drastic increase occurred in the first hour after the onset of the light. Nitrate uptake rate was shown to be dependent on illumination intensity, nitrate concentration, and temperature. These results point to an energy-linked uptake process. From the

Rudolf Tischner; Harald Lorenzen

1979-01-01

201

Nitrate in groundwater  

Microsoft Academic Search

An intensive intrusion of nitrate into many aquifers has occurred in the last 20 years. Measures are discussed to prevent high concentrations of this pollutant in pumping wells. In the long run a less intensive use of mineral fertilizers and a diminished disposal of livestock wastes in the catchment areas of pumping wells are the presuppositions for an acceptable concentration

WOLFGANG MEIER; ROLF MULL

1989-01-01

202

Nitrate transport and signalling  

Microsoft Academic Search

Physiological measurements of nitrate (NO2 3 ) uptake by roots have defined two systems of high and low affinity uptake. In Arabidopsis, genes encoding both of these two uptake systems have been identified. Most is known about the high affinity transport system (HATS) and its regulation and yet measurements of soil NO2 3 show that it is more often available

Anthony J. Miller; Xiaorong Fan; Mathilde Orsel; Susan J. Smith; Darren M. Wells

2007-01-01

203

Recovery of plutonium by pyroredox processing  

SciTech Connect

Using pyrochemical oxidation and reduction, we have developed a process to recover the plutonium in impure scrap with less than 95% plutonium. This plutonium metal was further purified by pyrochemical electrorefining. During development of the procedures, depleted electrorefining anodes were processed, and over 80% of the plutonium was recovered as high-purity metal in one electrorefining cycle. Over 40 kg of plutonium has been recovered from 55 kg of impure anodes with our procedures. 6 refs., 2 figs., 5 tabs.

McNeese, J.A.; Bowersox, D.F.; Christensen, D.C.

1985-01-01

204

Production of microspheres of thorium oxide, uranium oxide and plutonium oxide and their mixtures containing carbon  

Microsoft Academic Search

A process is desclosed for the production of microspheres of thorium oxide, uranium oxide or plutonium oxide and mixtures thereof, containing carbon. The microspheres are prepared by first forming an aqueous alkaline solution of a salt of said metals which will precipitate to a solid form in a concentrated alkaline medium together with an alkaline polymerizable organic monomer and carbon,

G. Bezzi; A. Facchini; G. Martignani; M. Pastore

1980-01-01

205

Probing phonons in plutonium  

SciTech Connect

Plutonium (Pu) is well known to have complex and unique physico-chemical properties. Notably, the pure metal exhibits six solid-state phase transformations with large volume expansions and contractions along the way to the liquid state: {alpha} {yields} {beta} {yields} {gamma} {yields} {delta} {yields} {delta}{prime} {yields} {var_epsilon} {yields} liquid. Unalloyed Pu melts at a relatively low temperature {approx}640 C to yield a higher density liquid than that of the solid from which it melts, (Figure 1). Detailed understanding of the properties of plutonium and plutonium-based alloys is critical for the safe handling, utilization, and long-term storage of these important, but highly toxic materials. However, both technical and and safety issues have made experimental observations extremely difficult. Phonon dispersion curves (PDCs) are key experimenta l data to the understanding of the basic properties of Pu materials such as: force constants, sound velocities, elastic constants, thermodynamics, phase stability, electron-phonon coupling, structural relaxation, etc. However, phonon dispersion curves (PDCs) in plutonium (Pu) and its alloys have defied measurement for the past few decades since the discovery of this element in 1941. This is due to a combination of the high thermal-neutron absorption cross section of plutonium and the inability to grow the large single crystals (with dimensions of a few millimeters) necessary for inelastic neutron scattering. Theoretical simulations of the Pu PDC continue to be hampered by the lack of suitable inter -atomic potentials. Thus, until recently the PDCs for Pu and its alloys have remained unknown experimentally and theoretically. The experimental limitations have recently been overcome by using a tightly focused undulator x-ray micro-beam scattered from single -grain domains in polycrystalline specimens. This experimental approach has been applied successfully to map the complete PDCs of an fcc d-Pu-Ga alloy using the high resolution inelastic x-ray scattering (HRIXS) capability on ID28. The complete PDCs for an fcc Pu-0.6 wt% Ga alloy are plotted in Figure 2, and represent the first full set of phonon dispersions ever determined for any Pu-bearing materials. The solid curves (red) are calculated using a standard Born-von Karman (B-vK) force constant model. An adequate fit to the experimental data is obtained if interactions up to the fourth-nearest neighbours are included. The dashed curves (blue) are recent dynamical mean field theory (DMFT) results by Dai et al. The elastic moduli calculated from the slopes of the experimental phonon dispersion curves near the {Lambda} point are: C{sub 11} = 35.3 {+-} 1.4 GPa, C{sub 12} = 25.5 {+-} 1.5 GPa and C{sub 44} = 30.53 {+-} 1.1 GPa. These values are in excellent agreement with those of the only other measurement on a similar alloy (1 wt % Ga) using ultrasonic techniques as well as with those recently calculated from a combined DMFT and linear response theory for pure {delta}-Pu. Several unusual features, including a large elastic anisotropy, a small shear elastic modulus C{prime}, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the [111] transverse modes are found. These features can be related to the phase transitions of plutonium and to strong coupling between the lattice structure and the 5f valence instabilities. The HRIXS results also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium. The experimental-theoretical agreements shown in Figure 2 in terms of a low shear elastic modulus C{prime}, a Kohn-like anomaly in the T{sub 1}[011] branch, and a large softening of the T[111] modes give credence to the DMFT approach for the theoretical treatment of 5f electron systems of which {delta}-Pu is a classic example. However, quantitative differences remain. These are the position of the Kohn anomaly along the T{sub 1}[011] branch, the energy maximum of the T[111] mode s

Wong, Joe; Krisch, M.; Farber, D.; Occelli, F.; Schwartz, A.; Chiang, T.C.; Wall, M.; Boro, C.; Xu, Ruqing (UIUC); (LLNL); (ESRF); (LANL)

2010-11-16

206

Quantitative Infrared Spectrophotometry of Organic Nitrate Esters.  

National Technical Information Service (NTIS)

A quantitative infrared analysis of the N=O asymmetric stretching vibration band for the nitrate esters, ethyl nitrate, amyl nitrate, ethylene glycol dinitrate, glycerol trinitrate, and cellulose nitrate (12.53% N) is presented. Two solvents, chloroform a...

C. L. Hickman Y. P. Carignan

1972-01-01

207

Low temperature oxidation of plutonium  

SciTech Connect

The initial oxidation of gallium stabilized {delta}-plutonium metal at 193 K has been followed using x-ray photoelectron spectroscopy. On exposure to Langmuir quantities of oxygen, plutonium rapidly forms a trivalent oxide followed by a tetravalent plutonium oxide. The growth modes of both oxides have been determined. Warming the sample in vacuum, the tetravalent oxide reduces to the trivalent oxide. The kinetics of this reduction reaction have followed and the activation energy has been determined to be 38.8 kJ mol{sup -1}.

Nelson, Art J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Roussel, Paul [AWE, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

2013-05-15

208

Nitrate, bacteria and human health  

Microsoft Academic Search

Nitrate is generally considered a water pollutant and an undesirable fertilizer residue in the food chain. Research in the 1970s indicated that, by reducing nitrate to nitrite, commensal bacteria might be involved in the pathogenesis of gastric cancers and other malignancies, as nitrite can enhance the generation of carcinogenic N-nitrosamines. More recent studies indicate that the bacterial metabolism of nitrate

Eddie Weitzberg; Jeff A. Cole; Nigel Benjamin; Jon O. Lundberg

2004-01-01

209

The Economics of Nitrate Pollution  

Microsoft Academic Search

Nitrogen is essential to plant growth and, yet, excessive levels of nitrates in soil can cause problems of environmental pollution. In this paper, the author first considers the nitrogen cycles, tracing the movements of nitrogen to and from soils. The problems of excessive nitrate levels are then outlined, being effects on human health and eutrophication of water courses. Nitrate pollution

Nick Hanley

1990-01-01

210

The chemistry of tributyl phosphate at elevated temperatures in the Plutonium Finishing Plant Process Vessels  

SciTech Connect

Potentially violent chemical reactions of the tributyl phosphate solvent used by the Plutonium Finishing Plant at the Hanford Site were investigated. There is a small probability that a significant quantity of this solvent could be accidental transferred to heated process vessels and react there with nitric acid or plutonium nitrate also present in the solvent extraction process. The results of laboratory studies of the reactions show that exothermic oxidation of tributyl phosphate by either nitric acid or actinide nitrates is slow at temperatures expected in the heated vessels. Less than four percent of the tributyl phosphate will be oxidized in these vented vessels at temperatures between 125{degrees}C and 250{degrees}C because the oxidant will be lost from the vessels by vaporization or decomposition before the tributyl phosphate can be extensively oxidized. The net amounts of heat generated by oxidation with concentrated nitric acid and with thorium nitrate (a stand-in for plutonium nitrate) were determined to be about -150 and -220 joules per gram of tributyl phosphate initially present, respectively. This is not enough heat to cause violent reactions in the vessels. Pyrolysis of the tributyl phosphate occurred in these mixtures at temperatures of 110{degrees}C to 270{degrees}C and produced mainly 1-butene gas, water, and pyrophosphoric acid. Butene gas generation is slow at expected process vessel temperatures, but the rate is faster at higher temperatures. At 252{degrees}C the rate of butene gas generated was 0.33 g butene/min/g of tributyl phosphate present. The measured heat absorbed by the pyrolysis reaction was 228 J/g of tributyl phosphate initially present (or 14.5 kcal/mole of tributyl phosphate). Release of flammable butene gas into process areas where it could ignite appears to be the most serious safety consideration for the Plutonium Finishing Plant.

Barney, G.S.; Cooper, T.D.

1994-06-01

211

Rapid Nondestructive Plutonium Isotopic Analysis.  

National Technical Information Service (NTIS)

Methods for plutonium isotopic measurements have been evaluated for nuclear safeguards inventory verification. A mobile, real-time, nondestructive assay, gamma-ray spectrometric measurement system has been assembled, moved and operated at several nuclear ...

J. E. Fager F. P. Brauer

1978-01-01

212

Plutonium storage thermal analysis (U).  

National Technical Information Service (NTIS)

Thermal modeling of plutonium metal ingots stored in food pack cans provides information useful for performing stored material safety evaluations. Four storage can geometries were modeled, and several conclusions can be made from the 14 cases analyzed. Th...

S. J. Hensel S. Y. Lee J. B. Schaade

1997-01-01

213

Aqueous Syntheses of Forsterite (Mg 2 SiO 4 ) and Enstatite (MgSiO 3 )  

Microsoft Academic Search

Forsterite MgSiO4 and enstatite MgSiO3 were synthesized by two different aqueous processes. TEOS was directly hydrolyzed in aqueous solutions of magnesium nitrate, giving solutions of magnesium nitrate and silicic acid. For the first process these solutions were spray-dried and the powders heat treated to decompose the nitrate; and for the second one they were precipitated in a solution of ethylenediamine

André Douy

2002-01-01

214

Influence of chemical form, feeding regimen, and animal species on the gastrointestinal absorption of plutonium  

SciTech Connect

We evaluated the effect of chemical form and feeding regimen on the gastrointestinal (GI) absorption of plutonium in adult mice at plutonium concentrations relevant to the establishment of drinking water standards. Mean fractional GI absorption values in fasted adult mice were: Pu(VI) bicarbonate, 15 x 10/sup -4/; Pu(IV) bicarbonate, 20 x 10/sup -4/; Pu(IV) nitrate (pH2), 17 x 10/sup -4/; Pu(IV) citrate, 24 x 10/sup -4/; and Pu(IV) polymer, 3 x 10/sup -4/. Values in fed adult mice were: Pu(VI) bicarbonate, 1.4 x 10/sup -4/; Pu(IV) polymer, 0.3 x 10/sup -4/. Pu(VI) is the oxidation state in chlorinated drinking waters and Pu(IV) is the oxidation state in many untreated natural waters. To assess the validity of extrapolating data from mice to humans, we also determined the GI absorption of Pu(VI) bicarbonate in adult baboons with a dual-isotope method that does not require animal sacrifice. Fractional GI absorption values obtained by this method were 23 +- 10 x 10/sup -4/ for fasted baboons (n=5) and 1.4 +- 0.9 x 10/sup -4/ for fed baboons (n=3). We have so far validated this method in one baboon and are currently completing validation in two additional animals. At low plutonium concentrations, plutonium oxidation state (Pu(VI) vs Pu(IV)) and administration medium (bicarbonate vs nitrate vs citrate) had little effect on the GI absorption of plutonium in mice. Formation of Pu(IV) polymers and animal feeding decreased the GI absorption of plutonium 5- to 10-fold. The GI absorption of Pu(VI) bicarbonate in both fed and fasted adult baboons appeared to be the same as in fed and fasted adult mice, respectively. 17 refs., 2 tabs.

Bhattacharyya, M.H.; Larsen, R.P.; Cohen, N.; Ralston, L.G.; Oldham, R.D.; Moretti, E.S.; Ayres, L.

1985-01-01

215

Plutonium measurements near background levels  

SciTech Connect

The Rocky Flats Plant (RFP) is part of a nationwide nuclear weapons research, development, and production complex administered by the United States Department of Energy (DOE). Low-levels of environmental Plutonium occurs in and about RFP as a result of plant operations. Plutonium is a key element in remediation investigations and surface water discharge limits. Most of the plutonium analyses at RFP measure concentrations at or near background levels. Measurements often show little, if any, plutonium in the media being sampled, except at known contamination sites. Many plutonium results are less than the calculated minimum detectable-level (MDL). (MDL is an a priori estimate of the activity concentration that can be practically achieved under a specified set of typical measurement conditions.) This paper investigates the relationship between plutonium concentrations and the counting uncertainty when measurements are near background, and suggests why the MDL should not be used as a criteria for limiting data. Issues with defining site background and determining attainment of standards are presented.

Not Available

1992-01-01

216

Plutonium measurements near background levels  

SciTech Connect

The Rocky Flats Plant (RFP) is part of a nationwide nuclear weapons research, development, and production complex administered by the United States Department of Energy (DOE). Low-levels of environmental Plutonium occurs in and about RFP as a result of plant operations. Plutonium is a key element in remediation investigations and surface water discharge limits. Most of the plutonium analyses at RFP measure concentrations at or near background levels. Measurements often show little, if any, plutonium in the media being sampled, except at known contamination sites. Many plutonium results are less than the calculated minimum detectable-level (MDL). (MDL is an a priori estimate of the activity concentration that can be practically achieved under a specified set of typical measurement conditions.) This paper investigates the relationship between plutonium concentrations and the counting uncertainty when measurements are near background, and suggests why the MDL should not be used as a criteria for limiting data. Issues with defining site background and determining attainment of standards are presented.

Not Available

1992-08-01

217

Ammonium nitrate explosive systems  

DOEpatents

Novel explosives which comprise mixtures of ammonium nitrate and an ammonium salt of a nitroazole in desired ratios are disclosed. A preferred nitroazole is 3,5-dinitro-1,2,4-triazole. The explosive and physical properties of these explosives may readily be varied by the addition of other explosives and oxidizers. Certain of these mixtures have been found to act as ideal explosives.

Stinecipher, Mary M. (Los Alamos, NM); Coburn, Michael D. (Los Alamos, NM)

1981-01-01

218

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

SciTech Connect

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

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

2009-09-10

219

Proceedings of the Plutonium Futures ? The Science 2006 Conference  

SciTech Connect

Plutonium Futures--The Science 2006 provided opportunities to examine present knowledge of the chemical and physical properties of plutonium and other actinides in complex media and materials; to discuss the current and emerging science (chemistry, physics, materials science, nuclear science, and environmental effects) of plutonium and actinides relevant to enhancing global nuclear security; and to exchange ideas. This international conference also provided a forum for illustrating and enhancing capabilities and interests, and assessing issues in these areas. U.S. and international scientists, engineers, faculty, and students from universities, national laboratories, and DOE's nuclear complex were encouraged to participate and make technical contributions. The Conference ran from Sunday, July 9th through Thursday, July 13th. A popular aspect of the conference was the opening tutorial session on Sunday afternoon intended for students and scientists new to the area of plutonium research. The tutorial was well attended by novices and veterans alike, and featured such diverse topics as; plutonium metallurgy, plutonium in the environment, and international arms control and nonproliferation. Two plenary lectures began each morning and each afternoon session and highlighted the breakout sessions on coordination/organometallic chemistry, solid-state physics, environmental chemistry, materials science, separations and reprocessing, advanced fuels and waste forms, phase transformations, solution and gas-phase chemistry, compounds and complexes, electronic structure and physical properties, and more. Chemistry Highlights--Among the many chemistry highlights presented in this proceedings are the overview of concepts and philosophies on inert nuclear fuel matrices and concerns about the ever-increasing amounts of minor actinides and plutonium generated in the fuel cycle. The various ideas involve multiple reduction schemes for these materials, suggesting fuels for 'burning' or 'cradle-to-grave' accountability for various reactor types. Related work is presented on identification of the unique reaction mechanisms and identification of the intermediate products, including Pu(III), at the end of the PUREX process. In the important area of nuclear forensics, actual scenarios of nuclear materials confiscation and the successes of applying forensics protocols to determine attribution and possible intention are provided. In the area of reactor incidents, there is no other place on Earth like the Chernobyl Site Object Shelter and radioactive aerosol particle characterization studies reflect an important effort described herein. An additional report from another unique environmental site presents results on radionuclide monitoring, fate, and transport in the ecosystem of the Yenisei River in the Krasoyarsk region. In the area of nuclear waste disposal, a study of the ion irradiation damage to pyrochlore compounds with varying amounts of host elements and actinide dopants is presented. Papers on both the aqueous and nonaqueous chemistry of plutonium and other actinides are presented including anhydrous coordination chemistry and redox behavior in the presence of humic materials and the their sorption on common minerals in the environment. Also published herein are reports on the field of anhydrous coordination chemistry of the transuranic elements where there is scarce information. Solid-State and Materials Highlights--Plutonium solid-state and materials research is represented in these proceedings by a wealth of leading edge discovery class research. The breadth of this research is reflected in the topics covered: solid-state; materials science; superconductivity; phase changes, phonons, and entropy; electronic structure and physical properties; surface science and corrosion; and radiation effects, defects, impurities, and property changes. Indeed the scientific challenge and excitement of plutonium can best be highlighted by quoting the tutorial prospectus of Drs. Sarrao and Schwartz. 'Plutonium has long been recognized as a complex and scie

Fluss, M; Hobart, D; Allan, P; Jarvinen, G

2007-07-12

220

Reduction of nitrate and nitrite salts under hydrothermal conditions  

SciTech Connect

The feasibility of reducing nitrate/nitrite salts under hydrothermal conditions for the treatment of aqueous mixed wastes stored in the underground tanks at the Department of Energy site at Hanford, Washington was studied. The reduction of nitrate and nitrite salts by reaction with EDTA using a tank waste simulant was examined at temperatures between 623K and 800K and pressures between 0.6 and 1.2 kbar. Continuous flow reactors were used to determine kinetics and products of reactions. All reactions were studied under pressures high enough to produce single phase conditions. The reactions are rapid, go to completion in less than a minute, and produce simple products, such as carbonate, nitrogen, and nitrous oxide gases. The experimental results demonstrate the ability of chemical reactions under hydrothermal conditions to reduce the nitrate and nitrite salts and destroy organic compounds in the waste mixtures.

Foy, B.R.; Dell`Orco, P.C.; Wilmanns, E.; McInroy, R.; Ely, J.; Robinson, J.M.; Buelow, S.J.

1994-10-01

221

Measurement of Nitrite and Nitrate in Biological Fluids by Gas Chromatography–Mass Spectrometry and by the Griess Assay: Problems with the Griess Assay—Solutions by Gas Chromatography–Mass Spectrometry  

Microsoft Academic Search

Assay methods based on the Griess reaction are frequently used to measure nitrite and nitrate in urine, plasma, and other biological fluids. With minor exceptions, careful attention has not been paid in extending the Griess assay from aqueous solutions to biological fluids. In the present study, parallel measurements of nitrite and nitrate were performed in urine, plasma, and aqueous solutions

Dimitrios Tsikas; Frank-Mathias Gutzki; Stefan Rossa; Heinke Bauer; Christine Neumann; Katja Dockendorff; Jörg Sandmann; Jürgen C. Frölich

1997-01-01

222

COMPARISON OF MUTAGENIC ACTIVITIES OF SEVERAL PEROXYACYL NITRATES  

EPA Science Inventory

Salmonella typhimurium strain TA100 was exposed to a series of peroxyacyl nitrates including peroxyacetyl nitrate (PAN), peroxypropionyl nitrate peroxybutyryl nitrate (PBN), peroxybenzoyl nitrate (PBzN), and chlororoxyacetyl nitrate (CPAN). as phase concentrations for the individ...

223

COMPARISON OF MUTAGENIC ACTIVITIES OF SEVERAL PEROXYACL NITRATES  

EPA Science Inventory

Salmonella typhimurium, strain TA100 was exposed to a series of peroxyacyl nitrates including peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), peroxybutyryl nitrate (PBN), peroxybenzoyl nitrate (PBzN), and chloroperoxyacetyl nitrate (CPAN). as-phase concentrations for t...

224

Mound Laboratory Environmental Plutonium Study, 1974.  

National Technical Information Service (NTIS)

In 1974, the sediment in certain waterways near the laboratory site appeared to exhibit plutonium-238 concentrations higher than the expected baseline levels. A comprehensive environmental plutonium-238 study to determine the full extent of the contaminat...

D. R. Rogers

1975-01-01

225

Plutonium and Americium Separation from Salts.  

National Technical Information Service (NTIS)

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

P. G. Hagan F. J. Miner

1976-01-01

226

Analysis of nitrate in environmental samples by reversed-phase HPLC  

Microsoft Academic Search

A method is presented for the analysis of nitrate in natural waters and waste water by high-performance liquid chromatography (HPLC) with a reversed-phase octadecyl column, aqueous phosphoric acid\\/dihydrogen phosphate mobile phase, and UV detector. The optimum nitrate concentration is 0.3 to 3 mg\\/L as N with linear detector response below 3 mg\\/L. The detection limit is 0.007 mg\\/L. Relative standard

1987-01-01

227

Plutonium Proliferation: The Achilles Heel of Disarmament  

ScienceCinema

Plutonium is a byproduct of nuclear fission, and it is produced at the rate of about 70 metric tons a year in the world's nuclear power reactors. Concerns about civilian plutonium ran high in the 1970s and prompted enactment of the Nuclear Non-Proliferation Act of 1978 to give the United States a veto over separating plutonium from U.S.-supplied uranium fuel. Over the years, however, so-called reactor-grade plutonium has become the orphan issue of nuclear non-proliferation, largely as a consequence of pressures from plutonium-separating countries. The demise of the fast breeder reactor and the reluctance of utilities to introduce plutonium fuel in light-water reactors have resulted in large surpluses of civilian, weapons-usable plutonium, which now approach in size the 250 tons of military plutonium in the world. Yet reprocessing of spent fuel for recovery and use of plutonium proceeds apace outside the United States and threatens to overwhelm safeguards and security measures for keeping this material out of the hands of nations and terrorists for weapons. A number of historical and current developments are reviewed to demonstrate that plutonium commerce is undercutting efforts both to stop the spread of nuclear weapons and to work toward eliminating existing nuclear arsenals. These developments include the breakdown of U.S. anti-plutonium policy, the production of nuclear weapons by India with Atoms-for-Peace plutonium, the U.S.-Russian plan to introduce excess military plutonium as fuel in civilian power reactors, the failure to include civilian plutonium and bomb-grade uranium in the proposed Fissile Material Cutoff Treaty, and the perception of emerging proliferation threats as the rationale for development of a ballistic missile defense system. Finally, immobilization of separated plutonium in high-level waste is explored as a proliferation-resistant and disarmament-friendly solution for eliminating excess stocks of civilian and military plutonium.

228

China's HEU and Plutonium Production and Stocks  

Microsoft Academic Search

This article discusses the history of China's production of highly enriched uranium and plutonium for nuclear weapons and uses new public information to estimate the amount of highly enriched uranium and plutonium China produced at its two gaseous diffusion plants and two plutonium production complexes. The new estimates in this article are that China produced 20 ± 4 tons of

HUI ZHANG

2011-01-01

229

AES And XPS Study of Plutonium Oxidation.  

National Technical Information Service (NTIS)

The initial oxidation of plutonium metal at 27 exp 0 C has been studied using AES and XPS. Initially a clean plutonium surface was prepared by Ar exp + bombardment and 500 exp 0 C-Ar exp + bombardment heat cycles. Changes occurring in the plutonium Auger ...

D. T. Larson

1979-01-01

230

Trace determination of nitrated polycyclic aromatic hydrocarbons using liquid chromatography with on-line electrochemical reduction and fluorescence detection  

Microsoft Academic Search

An efficient clean-up procedure coupled with a high performance liquid chromatography (HPLC) with on-line electrochemical (EC) reduction and fluorescence detection (FLD) was developed to quantify nitrated polycyclic aromatic hydrocarbons (NPAHs) in the airborne particulate. In this process, NPAHs were extracted ultrasonically followed by analysis by using a reversed phase column with an aqueous eluent containing 70% aqueous acetonitrile and sodium

Ching-Tang Kuo; Hong-Wen Chen; Shaw-Tao Lin

2003-01-01

231

Vitrification of excess plutonium  

SciTech Connect

As a result of nuclear disarmament activities, many thousands of nuclear weapons are being retired in the US and Russia, producing a surplus of about 50 MT of weapons grade plutonium (Pu) in each country. In addition, the Department of Energy (DOE) has more than 20 MT of Pu scrap, residue, etc., and Russia is also believed to have at least as much of this type of material. The entire surplus Pu inventories in the US and Russia present a clear and immediate danger to national and international security. It is important that a solution be found to secure and manage this material effectively and that such an effort be implemented as quickly as possible. One option under consideration is vitrification of Pu into a relatively safe, durable, accountable, proliferation-resistant form. As a result of decades of experience within the DOE community involving vitrification of a variety of hazardous and radioactive wastes, this existing technology can now be expanded to include immobilization of large amounts of Pu. This technology can then be implemented rapidly using the many existing resources currently available. A strategy to vitrify many different types of Pu will be discussed. In this strategy, the arsenal of vitrification tools, procedures and techniques already developed throughout the waste management community can be used in a staged Pu vitrification effort. This approach uses the flexible vitrification technology already available and can even be made portable so that it may be brought to the source and ultimately, used to produce a common, borosilicate glass form for the vitrified Pu. The final composition of this product can be made similar to nationally and internationally accepted HLW glasses.

Wicks, G.G.; Mckibben, J.M.; Plodinec, M.J.

1994-12-31

232

Preparation of Plutonium Metal, (I)  

Microsoft Academic Search

Ammonium plutonium(IV) fluorides, PuF4.7\\/6NH4F and PuF4.2NH4F, were prepared by the addition of an acidic solution containing Pu(IV) to a mixed solution of NH4F and HF. Anhydrous PuF3 was obtained by thermal decomposition of the ammonium plutonium(IV) fluorides under reduced pressure or else in an inert gas flow. The anhydrous fluoride was then reduced with Li vapor to Pu metal. Cerium

Keiji NAITO; Masaru KOJIMA; Kinji OUCHI; Taneaki YAHATA

1971-01-01

233

Plutonium stabilization and packaging system  

SciTech Connect

This document describes the functional design of the Plutonium Stabilization and Packaging System (Pu SPS). The objective of this system is to stabilize and package plutonium metals and oxides of greater than 50% wt, as well as other selected isotopes, in accordance with the requirements of the DOE standard for safe storage of these materials for 50 years. This system will support completion of stabilization and packaging campaigns of the inventory at a number of affected sites before the year 2002. The package will be standard for all sites and will provide a minimum of two uncontaminated, organics free confinement barriers for the packaged material.

NONE

1996-05-01

234

Complexation of Plutonium (IV) with Fluoride at Variable Temperatures  

SciTech Connect

The complexation of Pu(IV) with fluoride at elevated temperatures was studied by solvent extraction technique. A solution of NaBrO3 was used as holding oxidant to maintain the oxidation state of plutonium throughout the experiments. The distribution ratio of Pu(IV) between the organic and aqueous phases was found to decrease as the concentrations of fluoride were increased. Stability constants of the 1:1 and 1:2 Pu(IV)-F- complexes, dominant in the aqueous phase under the experimental conditions, were calculated from the effect of fluoride ions on the distribution ratio. The thermodynamic parameters, including enthalpy and entropy of complexation between Pu(IV) and fluoride at 25 degrees C - 55 degrees C were calculated from the stability constants at different temperatures by using the Van’t Hoff equation.

Xia, Yuanxian; Rao, Linfeng; Friese, Judah I.; Moore, Dean A.; Bachelor, Paula P.

2010-02-02

235

Thermodynamics of Uranium and Nitric Acid Extraction from Aqueous Solution of TBP/Diluent.  

National Technical Information Service (NTIS)

A thermodynamically consistent procedure for predicting distribution equilibria for uranyl nitrate and nitric acid between an aqueous solution and 30 vol % tributyl phosphate (TBP) in a hydrocarbon diluent is studied. Experimental work is developed in ord...

R. F. de Souza Freitas

1982-01-01

236

Thermal Decomposition of Nitrated Tributyl Phosphate  

SciTech Connect

Contact between tributyl phosphate and aqueous solutions of nitric acid and/or heavy metal nitrate salts at elevated temperatures can lead to exothermic reactions of explosive violence. Even though such operations have been routinely performed safely for decades as an intrinsic part of the Purex separation processes, several so-called ``red oil`` explosions are known to have occurred in the United States, Canada, and the former Soviet Union. The most recent red oil explosion occurred at the Tomsk-7 separations facility in Siberia, in April 1993. That explosion destroyed part of the unreinforced masonry walls of the canyon-type building in which the process was housed, and allowed the release of a significant quantity of radioactive material.

Paddleford, D.F. [Westinghouse Savannah River Company, Aiken, SC (United States); Hou, Y.; Barefield, E.K.; Tedder, D.W.; Abdel-Khalik, S.I. [Georgia Institute of Technology, GA (United States)

1995-01-01

237

Plutonium immobilization feed batching system concept report  

SciTech Connect

The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with high level waste glass for permanent storage. Feed batching is one of the first process steps involved with first stage plutonium immobilization. It will blend plutonium oxide powder before it is combined with other materials to make pucks. This report discusses the Plutonium Immobilization feed batching process preliminary concept, batch splitting concepts, and includes a process block diagram, concept descriptions, a preliminary equipment list, and feed batching development areas.

Erickson, S.

2000-07-19

238

76 FR 70366 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...NPRM for the Ammonium Nitrate Security Program. The agenda for the public...Department's Ammonium Nitrate Security Program Web site, at http://www.dhs...programs/ammonium-nitrate-security-program.shtm. This...

2011-11-14

239

76 FR 62311 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...NPRM) for the Ammonium Nitrate Security Program. The agenda for the public...Department's Ammonium Nitrate Security Program Web site in mid-October at http...programs/ammonium-nitrate-security-program.shtm. Each...

2011-10-07

240

[The nitrate content in milk].  

PubMed

Analytical possibilities for nitrate determination in milk on the base of photometric methods are discussed. An automated method, similar to Nijhuis u. a. (1979), is proposed using flow stream analyser ADM 300. Natrium nitrate (5 g and 10 g/kg live weight resp.) was given to two dairy cows after morning feeding on the 1st and on the 3rd day of experiment. The increase of nitrate content in the milk was very quick, maximal concentrations after 2 h were found as 5.6 mg/l (animal 1) and 3.2 mg nitrate-N/l (animal 2). But nitrate also disappeared relatively quickly, after 24 h there only values were observed corresponding to normal range of 1 mg/l. PMID:1953343

Geissler, C; Steinhöfel, O; Ulbrich, M

1991-08-01

241

Nitrate reductase from Rhodopseudomonas sphaeroides.  

PubMed Central

The facultative phototroph Rhodopseudomonas sphaeroides DSM158 was incapable of either assimilating or dissimilating nitrate, although the organism could reduce it enzymatically to nitrite either anaerobically in the light or aerobically in the dark. Reduction of nitrate was mediated by a nitrate reductase bound to chromatophores that could be easily solubilized and functioned with chemically reduced viologens or photochemically reduced flavins as electron donors. The enzyme was solubilized, and some of its kinetic and molecular parameters were determined. It seemed to be nonadaptive, ammonia did not repress its synthesis, and its activity underwent a rapid decline when the cells entered the stationary growth phase. Studies with inhibitors and with metal antagonists indicated that molybdenum and possibly iron participate in the enzymatic reduction of nitrate. The conjectural significance of this nitrate reductase in phototrophic bacteria is discussed.

Kerber, N L; Cardenas, J

1982-01-01

242

Plutonium immobilization form evaluation  

SciTech Connect

The 1994 National Academy of Sciences study and the 1997 assessment by DOE`s Office of Nonproliferation and National Security have emphasized the importance of the overall objectives of the Plutonium Disposition Program of beginning disposition rapidly. President Clinton and other leaders of the G-7 plus one (`Political Eight`) group of states, at the Moscow Nuclear Safety And Security Summit in April 1996, agreed on the objectives of accomplishing disposition of excess fissile material as soon as practicable. To meet these objectives, DOE has laid out an aggressive schedule in which large-scale immobilization operations would begin in 2005. Lawrence Livermore National Laboratory (LLNL), the lead laboratory for the development of Pu immobilization technologies for the Department of Energy`s Office of Fissile Materials Disposition (MD), was requested by MD to recommend the preferred immobilization form and technology for the disposition of excess weapons-usable Pu. In a series of three separate evaluations, the technologies for the candidate glass and ceramic forms were compared against criteria and metrics that reflect programmatic and technical objectives: (1) Evaluation of the R&D and engineering data for the two forms against the decision criteria/metrics by a technical evaluation panel comprising experts from within the immobilization program. (2) Integrated assessment by LLNL immobilization management of the candidate technologies with respect to the weighted criteria and other programmatic objectives, leading to a recommendation to DOE/MD on the preferred technology based on technical factors. (3) Assessment of the decision process, evaluation, and recommendation by a peer review panel of independent experts. Criteria used to assess the relative merits of the immobilization technologies were a subset of the criteria previously used by MD to choose among disposition options leading to the Programmatic Environmental Impact Statement and Record of Decision for the Storage and Disposition of Weapons-Usable Fissile Materials, January 1997. Criteria were: (1) resistance to Pu theft, diversion, and recovery by a terrorist organization or rogue nation; (2) resistance to recovery and reuse by host nation; (3) technical viability, including technical maturity, development risk, and acceptability for repository disposal; (4) environmental, safety, and health factors; (5) cost effectiveness; and (6) timeliness. On the basis of the technical evaluation and assessments, in September, 1997, LLNL recommended to DOE/MD that ceramic technologies be developed for deployment in the planned Pu immobilization plant.

Gray, L. W., LLNL

1998-02-13

243

Plutonium Recycle: The Fateful Step  

ERIC Educational Resources Information Center

Calls attention to the fact that if the Atomic Energy Commission proceeds with its plans to authorize the nuclear power industry to use plutonium as a fuel in commercial nuclear reactors around the country, this will result in a dramatic escalation in the risks posed by nuclear power. (PEB)

Speth, J. Gustave; And Others

1974-01-01

244

Plutonium Chemistry of the Ocean.  

National Technical Information Service (NTIS)

Plutonium is a man-made element whose behavior in the marine environment is inadequately known at present. It has been studied intensively in connection with production of weapons and power sources and has been characterized as an extremely toxic substanc...

T. R. Folsom

1972-01-01

245

Removal of nitrate ions from water by activated carbons (ACs)—Influence of surface chemistry of ACs and coexisting chloride and sulfate ions  

NASA Astrophysics Data System (ADS)

Adsorptive removal of nitrate ions in aqueous solution using activated carbons (ACs) was examined. After ash was removed from Filtrasorb 400 AC, oxidation and outgassing and several heat treatments were carried out to modify the textural and surface properties of ACs. AC oxidized with 8 M nitric acid followed by outgassing at 900 °C (Ox-9OG) exhibited the greatest Langmuir adsorption capacity and affinity for nitrate removal among the total 7 ACs examined. Influence of coexisting chloride and sulfate ions was investigated as well to inspect the nitrate adsorption sites. The highest amount of sites which adsorbed nitrate ions exclusively could be observed for Ox-9OG adsorbent even though as great as 250 times greater number of chloride or sulfate ions over nitrate ions were present in the same aqueous system. Some basic oxygen species on carbon were estimated to work as selective adsorption sites for nitrate ions.

Ota, Kazunari; Amano, Yoshimasa; Aikawa, Masami; Machida, Motoi

2013-07-01

246

Nitrate concentrations under irrigated agriculture  

USGS Publications Warehouse

In recent years, considerable interest has been expressed in the nitrate content of water supplies. The most notable toxic effect of nitrate is infant methemoglobinemia. The risk of this disease increases significantly at nitrate-nitrogen levels exceeding 10 mg/l. For this reason, this concentration has been established as a limit for drinking water in many countries. In natural waters, nitrate is a minor ionic constituent and seldom accounts for more than a few percent of the total anions. However, nitrate in a significant concentration may occur in the vicinity of some point sources such as septic tanks, manure pits, and waste-disposal sites. Non-point sources contributing to groundwater pollution are numerous and a majority of them are related to agricultural activities. The largest single anthropogenic input of nitrate into the groundwater is fertilizer. Even though it has not been proven that nitrogen fertilizers are responsible for much of nitrate pollution, they are generally recognized as the main threat to groundwater quality, especially when inefficiently applied to irrigated fields on sandy soils. The biggest challenge facing today's agriculture is to maintain the balance between the enhancement of crop productivity and the risk of groundwater pollution. ?? 1982 Springer-Verlag New York Inc.

Zaporozec, A.

1983-01-01

247

Effect of Americium241 Content on Plutonium Radiation Source Terms  

Microsoft Academic Search

The management of excess plutonium by the US Department of Energy includes a number of storage and disposition alternatives. Savannah River Site (SRS) is supporting DOE with plutonium disposition efforts, including the immobilization of certain plutonium materials in a borosilicate glass matrix. Surplus plutonium inventories slated for vitrification include materials with elevated levels of Americium-241. The Am-241 content of plutonium

Rainisch

1998-01-01

248

Using Nitrogen and Oxygen Isotope Compositions of Nitrate to Distinguish Contaminant Sources in Hanford Soil and Groundwater  

SciTech Connect

The nitrogen ({delta}{sup 15}N) and oxygen ({delta}{sup 18}O) isotopic compositions of nitrate in the environment are primarily a function of the source of the nitrate. The ranges of isotopic compositions for nitrate resulting from common sources are outlined in Figure 1 from Kendall (1998). As noted on Figure 1, processes such as microbial metabolism can modify the isotopic compositions of the nitrate, but the effects of these processes are generally predictable. At Hanford, nitrate and other nitrogenous compounds were significant components of most of the chemical processes used at the site. Most of the oxygen in nitrate chemicals (e.g., nitric acid) is derived from atmospheric oxygen, giving it a significantly higher {delta}{sup 18}O value (+23.5{per_thousand}) than naturally occurring nitrate that obtains most of its oxygen from water (the {delta}{sup 18}O of Hanford groundwater ranges from -14{per_thousand} to -18{per_thousand}). This makes it possible to differentiate nitrate from Hanford site activities from background nitrate at the site (including most fertilizers that might have been used prior to the Department of Energy plutonium production activities at the site). In addition, the extreme thermal and chemical conditions that occurred during some of the waste processing procedures and subsequent waste storage in select single-shell tanks resulted in unique nitrate isotopic compositions that can be used to identify those waste streams in soil and groundwater at the site (Singleton et al., 2005; Christensen et al., 2007). This report presents nitrate isotope data for soil and groundwater samples from the Hanford 200 Areas and discusses the implications of that data for potential sources of groundwater contamination.

Conrad, Mark; Bill, Markus

2008-08-01

249

Extractive photometric determination of plutonium(IV) with Aliquat-336 and xylenol orange  

Microsoft Academic Search

A rapid extractive photometric method using Aliquat-336 and xylenol organe for the determination of plutonium(IV) at ?g levels\\u000a has been developed. Quantitative extraction is obtained from ?4M aqueous HNO3 medium, affording estimation in the presence of several commonly occurring impurities, viz. iron, uranium, fission products\\u000a and cladding materials. Effects of acidity, reagent concentration and diverse ions on the estimation have

J. P. Shukla; M. S. Subramanian

1978-01-01

250

A review of the corrosion and pyrophoricity behavior of uranium and plutonium  

SciTech Connect

This report presents a review of the corrosion and pyrophoricity behavior of uranium and plutonium. For each element, the reactions with oxygen, water vapor, and aqueous solutions are described in terms of reaction rates, products, and mechanisms. Their pyrophoric tendencies in terms of measured ignition temperatures are discussed, and the effects of the important variables specific area, gas composition, and prior storage rare stated. The implications of the observed behavior for current storage issues are considered.

Totemeier, T.C.

1995-06-01

251

Density of Hydroxylammonium Nitrate Solutions.  

National Technical Information Service (NTIS)

Hydroxylammonium nitrate is miscible with water in all proportions at room temperature. The densities of such salt solutions were measured using water and deuterium oxide as solvents. A second order equation is given to relate to molar concentration. Keyw...

R. A. Sasse M. A. Davies R. A. Fifer M. M. Decker A. J. Kotlar

1988-01-01

252

EXPERIENCES IN DECONTAMINATION & DEMOLITION OF A FORMER PLUTONIUM CONCENTRATION FACILITY HANFORD RESERVATION  

SciTech Connect

The 233-S Plutonium Concentration Facility received plutonium nitrate paste from the nearby Reduction-Oxidation (REDOX) Facility and concentrated the plutonium for shipment to Hanford's Plutonium Finishing Plant. Operations ceased in 1967 and the Facility languished in a state of minimal maintenance until the mid-1990's when a decision was made to decontaminate and demolish (D&D) it. This work is being performed as a pilot project that integrates DOE nuclear safety analysis and worker safety requirements with Environmental Protection Agency (EPA) requirements under CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act, 1980). The pilot project is a CERCLA non-time critical removal action. Difficulties were encountered during D&D. These included conflict between the development of the safety basis as an EPA pilot project and DOE requirements for safety analysis reports, updating the safety analysis to keep it current with field conditions, and major difficulties with nondestructive assays (NDA) of the contaminated waste. No demonstrable benefit has been obtained by integrating the EPA and DOE safety methodologies.

BISHOP, G.E.

2002-06-01

253

Compartmental model of nitrate retention in streams  

Microsoft Academic Search

A compartmental modeling approach is presented to route nitrate retention along a cascade of stream reach sections. A process transfer function is used for transient storage equations with first-order reaction terms to represent nitrate uptake in the free stream and denitrification in the storage regions. In the context of a short-term nitrate injection we define nitrate assimilative capacity as 1

B. R. Faulkner; M. E. Campana

2007-01-01

254

Air transport of plutonium metal: content expansion initiative for the plutonium air transportable (PAT01) packaging  

SciTech Connect

The National Nuclear Security Administration (NNSA) has submitted an application to the Nuclear Regulatory Commission (NRC) for the air shipment of plutonium metal within the Plutonium Air Transportable (PAT-1) packaging. The PAT-1 packaging is currently authorized for the air transport of plutonium oxide in solid form only. The INMM presentation will provide a limited overview of the scope of the plutonium metal initiative and provide a status of the NNSA application to the NRC.

Caviness, Michael L [Los Alamos National Laboratory; Mann, Paul T [NNSA/ALBUQUERQUE; Yoshimura, Richard H [SNL

2010-01-01

255

Air transport of plutonium metal : content expansion initiative for the Plutonium Air Transportable (PAT-1) packaging.  

SciTech Connect

The National Nuclear Security Administration (NNSA) has submitted an application to the Nuclear Regulatory Commission (NRC) for the air shipment of plutonium metal within the Plutonium Air Transportable (PAT-1) packaging. The PAT-1 packaging is currently authorized for the air transport of plutonium oxide in solid form only. The INMM presentation will provide a limited overview of the scope of the plutonium metal initiative and provide a status of the NNSA application to the NRC.

Mann, Paul T. (National Nuclear Security Administration); Caviness, Michael L. (Los Alamos National Laboratory); Yoshimura, Richard Hiroyuki

2010-06-01

256

Destruction of nitrates, organics, and ferrocyanides by hydrothermal processing  

SciTech Connect

This work targets the remediation of the aqueous mixed wastes stored in the underground tanks at the Department of Energy site in Hanford, Washington via hydrothermal processing. The feasibility of destroying the nitrate, organic, and ferrocyanide components of the wastes under supercritical and near critical conditions (623 {degree}K to 873{degree}K, 22.1 MPa to 103.4 MPa) is addressed. A novel method was developed for determining the solubility of nitrate salts in supercritical water solutions at pressures ranging from 24.8 MPa to 30.3 MPa (3600 psi to 4400 psi) and temperatures from 723 {degree}K to 798 {degree}K. Sodium nitrate solubilities ranged from 293 mg/kg at 24.8 MPa and 798 {degree}K to 1963 mg/kg at 30.3 MPa and 723{degree}K. Solubility was found to vary directly with pressure, and inversely with temperature. An empirical relationship was developed for the estimation of sodium nitrate solubility at water densities between 0.08 and 0.16 kg/L and temperatures between 723{degree}K and 798{degree}K. A small volume batch reactor equipped with optical diagnostics was used to monitor the phase behavior of a diluted variant of a tank 101-SY simulant. Preliminary results suggest that a single phase is formed at 83 MPa at 773 {degree}K.

Robinson, J.M.; Foy, B.R.; Dell`Orco, P.C.; Anderson, G.; Archuleta, F.; Atencio, J.; Breshears, D.; Brewer, R.; Eaton, H.; McFarland, R.; McInroy, R.; Reynolds, T.; Sedillo, M.; Wilmanns, E.; Buelow, S.J.

1993-03-01

257

Alpha-plutonium's Grüneisen parameter.  

PubMed

Reported Grüneisen parameters ? of alpha-plutonium range from 3.0 to 9.6, which is remarkable because typical Grüneisen parameter uncertainty seldom exceeds ± 0.5. Our six new estimates obtained by different methods range from 3.2 to 9.6. The new estimates arise from Grüneisen's rule, from Einstein model and Debye model fits to low-temperature ?V/V, from the bulk modulus temperature dependence, from the zero-point-energy contribution to the bulk modulus, and from another Grüneisen relationship whereby ? is estimated from only the bulk modulus and volume changes with temperature (or pressure). We disregard several high estimates because of the itinerant-localized 5f-electron changes during temperature changes and pressure changes. Considering all these estimates, for alpha-plutonium, we recommend ? = 3.7 ± 0.4, slightly high compared with values for all elemental metals. PMID:21386421

Ledbetter, Hassel; Lawson, Andrew; Migliori, Albert

2010-04-28

258

Plutonium Immobilization Project -- Can loading  

SciTech Connect

The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP scope includes unloading transportation containers, preparing the feed streams, converting the metal feed to an oxide, adding the ceramic precursors, pressing the pucks, inspecting pucks, and sintering pucks. The PIP scope also includes loading the pucks into metal cans, sealing the cans, inspecting the cans, loading the cans into magazines, loading magazines into Defense Waste Processing Facility (DWPF) canisters, and transporting the canisters to the DWPF. The DWPF fills the canister with a mixture of high level radioactive waste and glass for permanent storage. Due to the radiation, remote equipment must perform PIP operations in a contained environment.

Kriikku, E.

2000-01-18

259

Plutonium Immobilization Can Loading Concepts  

SciTech Connect

The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses five can loading conceptual designs and the lists the advantages and disadvantages for each concept. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas. The can loading welder and cutter are very similar to the existing Savannah River Site (SRS) FB-Line bagless transfer welder and cutter and thus they are a low priority development item.

Kriikku, E. [Westinghouse Savannah River Company, AIKEN, SC (United States); Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.; Rogers, L.; Fiscus, J.; Dyches, G.

1998-05-01

260

Equilibrium Distribution of Uranyl Nitrate Between Nitric Acid and 7.5 Vol % Tbp.  

National Technical Information Service (NTIS)

The distribution of nitric acid and uranyl nitrate between aqueous solution and 7.5 vol percent tributyl phosphate in normal paraffin diluent was measured at 23, 45, and 60 exp 0 C. The data are consistent with behavior expected from theory and with previ...

M. C. Thompson, B. E. Murphree, R. L. Shankle

1975-01-01

261

HOT-ATOM CHEMISTRY OF HEXAMMINE-CHROMIUM(III) NITRATE IN THE SOLID STATE  

Microsoft Academic Search

A heterogeneous extraction method for enriching Cr⁵¹ recoil atoms ; in neutron-irradiated hexamminechromium(III) nitrate was investigated. The ; mechanisms of the reaction are discussed. The Cr⁵¹ atoms were extracted ; and enriched in the aqueous phase by shaking the target powder with concentrated ; HNOâ. Chemical forms of the recoil atoms were also studied. (M.C.G.);

Nagao Ikeda; Kenji Yoshihara; Hiroshi Ebihara; Kiyomi Suzuki

1961-01-01

262

Nitrate assimilation in Lotus japonicus.  

PubMed

This paper summarizes some recent advances in the understanding of nitrate assimilation in the model legume Lotus japonicus. First, different types of experimental evidence are presented that emphasize the importance of the root in the nitrate-reducing assimilatory processes in this plant. Secondly, the main results from an ethyl methanesulphonate mutagenesis programme are presented. In this programme, chlorate-resistant and photorespiratory mutants were produced and characterized. The phenotype of one particular chlorate-resistant mutant suggested the importance of a low-affinity nitrate transport system for growth of L. japonicus plants under nitrate nutrition. The phenotype of photorespiratory mutants, affected in all forms of plastid glutamine synthetase in leaves, roots, and nodules, indicated that plastid glutamine synthetase was not required for primary nitrate assimilation nor for the symbiotic associations of the plant (nodulation, mycorrhization), provided photorespiration was suppressed. However, the phenotype of these mutants confirmed that plastid glutamine synthetase was required for the reassimilation of ammonium released by photorespiration. Finally, different aspects of the relationship between nitrate assimilation and osmotic stress in L. japonicus are also discussed, with specific reference to the biosynthesis of proline as an osmolyte. PMID:15911564

Márquez, Antonio J; Betti, Marco; García-Calderón, Margarita; Pal'ove-Balang, Peter; Díaz, Pedro; Monza, Jorge

2005-07-01

263

Plutonium Proliferation: The Achilles Heel of Disarmament  

Microsoft Academic Search

Plutonium is a byproduct of nuclear fission, and it is produced at the rate of about 70 metric tons a year in the world's nuclear power reactors. Concerns about civilian plutonium ran high in the 1970s and prompted enactment of the Nuclear Non-Proliferation Act of 1978 to give the United States a veto over separating plutonium from U.S.-supplied uranium fuel.

Leventhal

2001-01-01

264

Plutonium Production - ChemCases.com  

NSDL National Science Digital Library

Until 1942, bombardment of targets composed of uranium compounds with deuterons produced by a cyclotron was the only source of plutonium. In December 1942, FermiÂs controlled chain reaction at the University of Chicago produced tiny quantities of plutonium in addition to energy and fission products. In November 1943, a larger pilot reactor at Oak Ridge, Tennessee, known as X-10, went critical and began to produce plutonium.

Settle, Frank

265

Addressing mixed waste in plutonium processing  

SciTech Connect

The overall goal is the minimization of all waste generated in actinide processing facilities. Current emphasis is directed toward reducing and managing mixed waste in plutonium processing facilities. More specifically, the focus is on prioritizing plutonium processing technologies for development that will address major problems in mixed waste management. A five step methodological approach to identify, analyze, solve, and initiate corrective action for mixed waste problems in plutonium processing facilities has been developed.

Christensen, D.C.; Sohn, C.L. (Los Alamos National Lab., NM (United States)); Reid, R.A. (New Mexico Univ., Albuquerque, NM (United States). Anderson Schools of Management)

1991-01-01

266

PLUTONIUM METAL: OXIDATION CONSIDERATIONS AND APPROACH  

SciTech Connect

Plutonium is arguably the most unique of all metals when considered in the combined context of metallurgical, chemical, and nuclear behavior. Much of the research in understanding behavior and characteristics of plutonium materials has its genesis in work associated with nuclear weapons systems. However, with the advent of applications in fuel materials, the focus in plutonium science has been more towards nuclear fuel applications, as well as long term storage and disposition. The focus of discussion included herein is related to preparing plutonium materials to meet goals consistent with non-proliferation. More specifically, the emphasis is on the treatment of legacy plutonium, in primarily metallic form, and safe handling, packaging, and transport to meet non-proliferation goals of safe/secure storage. Elevated temperature oxidation of plutonium metal is the treatment of choice, due to extensive experiential data related to the method, as the oxide form of plutonium is one of only a few compounds that is relatively simple to produce, and stable over a large temperature range. Despite the simplicity of the steps required to oxidize plutonium metal, it is important to understand the behavior of plutonium to ensure that oxidation is conducted in a safe and effective manner. It is important to understand the effect of changes in environmental variables on the oxidation characteristics of plutonium. The primary purpose of this report is to present a brief summary of information related to plutonium metal attributes, behavior, methods for conversion to oxide, and the ancillary considerations related to processing and facility safety. The information provided is based on data available in the public domain and from experience in oxidation of such materials at various facilities in the United States. The report is provided as a general reference for implementation of a simple and safe plutonium metal oxidation technique.

Estochen, E.

2013-03-20

267

Influence of Iron Redox Transformations on Plutonium Sorption to Sediments  

SciTech Connect

Plutonium subsurface mobility is primarily controlled by its oxidation state, which in turn is loosely coupled to the oxidation state of iron in the system. Experiments were conducted to examine the effect of sediment iron mineral composition and oxidation state on plutonium sorption and oxidation state. A pH 6.3 vadose zone sediment containing iron oxides and iron-containing phyllosilicates was treated with various complexants (ammonium oxalate) and reductants (dithionite-citrate-bicarbonate) to selectively leach and/or reduce iron oxide and phyllosilicate phases. Mössbauer spectroscopy was used to identify initial iron mineral composition of the sediment and monitor dissolution and reduction of iron oxides. Sorption of Pu(V) was monitored over one week for each of six treated sediment fractions. Plutonium oxidation state speciation in the aqueous and solid phases was monitored using solvent extraction, coprecipitation, and XANES. Mössbauer spectroscopy showed that the sediment contained 25-30% hematite, 60-65% Al-goethite, and <10%Fe(III) in phyllosilicate; there was no detectable Fe(II). Upon reduction with a strong chemical reductant (dithionite-citrate buffer, DCB), much of the hematite and goethite disappeared and the Fe in the phyllosilicate reduced to Fe(II). The rate of sorption was found to correlate with the 1 fraction of Fe(II) remaining within each treated sediment phase. Pu(V) was the only oxidation state measured in the aqueous phase, irrespective of treatment, whereas Pu(IV) and much smaller amounts of Pu(V) and Pu(VI) were measured in the solid phase. Surface-mediated reduction of Pu(V) to Pu(IV) occurred in treated and untreated sediment samples; Pu(V) remained on untreated sediment surface for two days before reducing to Pu(IV). Similar to the sorption kinetics, the reduction rate was correlated with sediment Fe(II) concentration. The correlation between Fe(II) concentrations and Pu(V) reduction demonstrates the potential impact of changing iron mineralogy on plutonium subsurface transport through redox transition areas. These findings should influence the conceptual models of long-term stewardship of Pu contaminated sites that have fluctuating redox conditions, such as vadose zones or riparian zones.

Hixon, Amy E.; Hu, Yung-Jin; Kaplan, Daniel I.; Kukkadapu, Ravi K.; Nitsche, Heino; Qafoku, Odeta; Powell, Brian A.

2010-10-01

268

Plutonium Isotopic Measurements by Gamma-Ray Spectroscopy  

Microsoft Academic Search

The nondestructive assay of plutonium is important as a safeguard tool in accounting for stategic nuclear material. Several nondestructive assay techniques, e.g., calorimetry and spontaneous fission assay detectors, require a knowledge of plutonium and americium isotopic ratios to convert their raw data to total grams of plutonium. This paper describes a nondestructive technique for calculating plutonium-238, plutonium-240, plutonium-241 and americium-241

Francis X. Haas; John F. Lemming

1976-01-01

269

An Improved Plutonium Trifluoride Precipitation Flowsheet  

SciTech Connect

This report discusses results of the plutonium trifluoride two-stage precipitation study. A series of precipitation experiments was used to identify the significant process variables affecting precipitation performance. A mathematical model of the precipitation process was developed which is based on the formation of plutonium fluoride complexes. The precipitation model relates all process variables, in a single equation, to a single parameter which can be used to control the performance of the plutonium trifluoride precipitation process. Recommendations have been made which will optimize the FB-Line plutonium trifluoride precipitation process.

Harmon, H.D.

2001-06-26

270

Hydroxylamine nitrate self-catalytic kinetics study with adiabatic calorimetry.  

PubMed

Hydroxylamine nitrate (HAN) is an important member of the hydroxylamine compound family with applications that include equipment decontamination in the nuclear industry and aqueous or solid propellants. Due to its instability and autocatalytic behavior, HAN has been involved in several incidents at the Hanford and Savannah River Site (SRS) [Technical Report on Hydroxylamine Nitrate, US Department of Energy, 1998]. Much research has been conducted on HAN in different areas, such as combustion mechanism, decomposition mechanism, and runaway behavior. However, the autocatalytic decomposition behavior of HAN at runaway stage has not been fully addressed due to its highly exothermic and rapid decomposition behavior. This work is focused on extracting HAN autocatalytic kinetics and analyzing HAN critical behavior from adiabatic calorimetry measurements. A lumped autocatalytic kinetic model for HAN and associated model parameters are determined. Also the storage and handling critical conditions of diluted HAN solution without metal presence are quantified. PMID:18639378

Liu, Lijun; Wei, Chunyang; Guo, Yuyan; Rogers, William J; Sam Mannan, M

2009-03-15

271

Comparison of the Solubility of Plutonium-238 and Plutonium-239 Dioxide in in Vitro Bovine Ruminal-Gastrointestinal Fluids.  

National Technical Information Service (NTIS)

The alimentary solubility and behavior of plutonium-238 dioxide and plutonium-239 dioxide were compared in an artificial rumen and simulated bovine gastrointestinal fluids. Rumen juice was augmented with plutonium-238 dioxide particles of 0.096- mu m coun...

1979-01-01

272

Aqueous ferrofluids based on manganese and cobalt ferrites  

Microsoft Academic Search

Synthesis of two new aqueous ferrofluids is performed chemically according to Massart's procedure. Manganese and cobalt ferrite magnetic particles are precipitated and treated in order to obtain colloidal sols by creating a charge density on their surface. Such “ionic” ferrofluids can be prepared in an acidic (after a treatment by ferric nitrate) or in an alkaline medium at a concentration

Francisco Augusto Tourinho; Raymonde Franck; René Massart

1990-01-01

273

Extraction of Th(IV), La(III), and Y(III) nitrates with a composite solid extractant based on a polymeric support impregnated with trialkylmethylammonium nitrate  

Microsoft Academic Search

Extraction of Th(IV), La(III), and Y(III) from aqueous solutions containing 0–4 M sodium nitrate with a composite solid extractant\\u000a based on a polymeric support impregnated with trialkylmethylammonium nitrate (Aliquat-336) was studied. The extraction isotherms\\u000a were analyzed assuming that lanthanides and thorium are extracted with the solid extractant in the form of complexes (R4N)2[Ln(NO3)5] and (R4N)2[Th(NO3)6], respectively. The extraction constants were

A. K. Pyartman; V. A. Keskinov; V. V. Lishchuk; A. V. Konstantinova; V. V. Belova

2006-01-01

274

Responsive Nature of 1,2,4,5-Tetrakis(2-pyridylthiomethyl)benzene Toward Group 12 Metal Nitrates: Activity of Coordinated Nitrate in Metal Complexes.  

PubMed

This study provides a detailed analysis on the responsive behavior of 1,2,4,5-tetrakis(2-pyridylthiomethyl)benzene (L) toward group 12 metal nitrates in both aqueous and nonaqueous media. The ligand L proved to be an environmentally responsive species, and structural investigations of its complexes with respective M(NO3)2 (M = Zn, Cd, and Hg) allowed one to remark on the inherent activity of the nitrate ion, resulting in a distinctively higher coordination number and dimensionality to the metal cations. PMID:24884196

Neeru; Yadav, Dolly; Tiwari, Geeta; Singh, Jai Deo; Butcher, Raymond J

2014-06-16

275

Laboratory study of nitrate photolysis in Antarctic snow. I. Observed quantum yield, domain of photolysis, and secondary chemistry.  

PubMed

Post-depositional processes alter nitrate concentration and nitrate isotopic composition in the top layers of snow at sites with low snow accumulation rates, such as Dome C, Antarctica. Available nitrate ice core records can provide input for studying past atmospheres and climate if such processes are understood. It has been shown that photolysis of nitrate in the snowpack plays a major role in nitrate loss and that the photolysis products have a significant influence on the local troposphere as well as on other species in the snow. Reported quantum yields for the main reaction spans orders of magnitude - apparently a result of whether nitrate is located at the air-ice interface or in the ice matrix - constituting the largest uncertainty in models of snowpack NOx emissions. Here, a laboratory study is presented that uses snow from Dome C and minimizes effects of desorption and recombination by flushing the snow during irradiation with UV light. A selection of UV filters allowed examination of the effects of the 200 and 305 nm absorption bands of nitrate. Nitrate concentration and photon flux were measured in the snow. The quantum yield for loss of nitrate was observed to decrease from 0.44 to 0.003 within what corresponds to days of UV exposure in Antarctica. The superposition of photolysis in two photochemical domains of nitrate in snow is proposed: one of photolabile nitrate, and one of buried nitrate. The difference lies in the ability of reaction products to escape the snow crystal, versus undergoing secondary (recombination) chemistry. Modeled NOx emissions may increase significantly above measured values due to the observed quantum yield in this study. The apparent quantum yield in the 200 nm band was found to be ?1%, much lower than reported for aqueous chemistry. A companion paper presents an analysis of the change in isotopic composition of snowpack nitrate based on the same samples as in this study. PMID:24985636

Meusinger, Carl; Berhanu, Tesfaye A; Erbland, Joseph; Savarino, Joel; Johnson, Matthew S

2014-06-28

276

Chemical and Radiochemical Composition of Thermally Stabilized Plutonium Oxide from the Plutonium Finishing Plant Considered as Alternate Feedstock for the Mixed Oxide Fuel Fabrication Facility  

SciTech Connect

Eighteen plutonium oxide samples originating from the Plutonium Finishing Plant (PFP) on the Hanford Site were analyzed to provide additional data on the suitability of PFP thermally stabilized plutonium oxides and Rocky Flats oxides as alternate feedstock to the Mixed Oxide Fuel Fabrication Facility (MFFF). Radiochemical and chemical analyses were performed on fusions, acid leaches, and water leaches of these 18 samples. The results from these destructive analyses were compared with nondestructive analyses (NDA) performed at PFP and the acceptance criteria for the alternate feedstock. The plutonium oxide materials considered as alternate feedstock at Hanford originated from several different sources including Rocky Flats oxide, scrap from the Remote Mechanical C-Line (RMC) and the Plutonium Reclamation Facility (PRF), and materials from other plutonium conversion processes at Hanford. These materials were received at PFP as metals, oxides, and solutions. All of the material considered as alternate feedstock was converted to PuO2 and thermally stabilized by heating the PuO2 powder at 950 C in an oxidizing environment. The two samples from solutions were converted to PuO2 by precipitation with Mg(OH)2. The 18 plutonium oxide samples were grouped into four categories based on their origin. The Rocky Flats oxide was divided into two categories, low- and high-chloride Rocky Flats oxides. The other two categories were PRF/RMC scrap oxides, which included scrap from both process lines and oxides produced from solutions. The two solution samples came from samples that were being tested at Pacific Northwest National Laboratory because all of the plutonium oxide from solutions at PFP had already been processed and placed in 3013 containers. These samples originated at the PFP and are from plutonium nitrate product and double-pass filtrate solutions after they had been thermally stabilized. The other 16 samples originated from thermal stabilization batches before canning at PFP. Samples varied in appearance depending on the original source of material. Rocky Flats items were mostly dark olive green with clumps that crushed easily with a mortar and pestle. PRF/RMC items showed more variability. These items were mostly rust colored. One sample contained white particles that were difficult to crush, and another sample was a dark grey with a mixture of fines and large, hard fragments. The appearance and feel of the fragments indicated they might be an alloy. The color of the solution samples was indicative of the impurities in the sample. The double-pass filtrate solution was a brown color indicative of the iron impurities in the sample. The other solution sample was light gray in color. Radiochemical analyses, including thermal ionization mass spectrometry (TIMS), alpha and gamma energy analysis (AEA and GEA), and kinetic phosphorescence analysis (KPA), indicate that these materials are all weapons-grade plutonium with consistent plutonium isotopics. A small amount of uranium (<0.14 wt%) is also present in these samples. The isotopic composition of the uranium varied widely but was consistent among each category of material. The primary water-soluble anions in these samples were Cl-, NO3-, SO42-, and PO43-. The only major anion observed in the Rocky Flats materials was Cl-, but the PRF/RMC samples had significant quantities of all of the primary anions observed. Prompt gamma measurements provide a representative analysis of the Cl- concentration in the bulk material. The primary anions observed in the solution samples were NO3-, and PO43-. The concentration of these anions did not exceed the mixed oxide (MOX) specification limits. Cations that exceeded the MOX specification limits included Cr, Fe, Ni, Al, Cu, and Si. All of the samples exceeded at least the 75% specification limit in one element.

Tingey, Joel M.; Jones, Susan A.

2005-07-01

277

Thermodynamics of the Extraction of Uranium and Nitric Acid from an Aqueous Solution with TBP/Diluent.  

National Technical Information Service (NTIS)

Herein is a study of a thermodynamically consistent method to predict the equilibrium distribution for uranyl nitrate and nitric acid between an aqueous solution and an organic phase composed of 30 vol % tributyl phosphate (TBP) in a hydrocarbon diluent. ...

R. F. S. Freitas

1984-01-01

278

Results of Active Test of Uranium-Plutonium Co-denitration Facility at Rokkasho Reprocessing Plant  

SciTech Connect

In the U-Pu co-denitration facility at Rokkasho Reprocessing Plant (RRP), Active Test which composes of 5 steps was performed by using uranium-plutonium nitrate solution that was extracted from spent fuels. During Active Test, two kinds of tests were performed in parallel. One was denitration performance test in denitration ovens, and expected results were successfully obtained. The other was validation and calibration of non-destructive assay (NDA) systems, and expected performances were obtained and their effectiveness as material accountancy and safeguards system was validated. (authors)

Numao, Teruhiko; Nakayashiki, Hiroshi; Arai, Nobuyuki; Miura, Susumu; Takahashi, Yoshiharu [Denitration Section, Plant Operation Dept., Reprocessing Plant, Reprocessing Business Division, Japan Nuclear Fuel Limited Rokkasho-mura, Kamikita-gun, Aomori-ken (Japan); Nakamura, Hironobu; Tanaka, Izumi [Technical Support Dept., Reprocessing Plant, Reprocessing Business Division, Japan Nuclear Fuel Limited Rokkasho-mura, Kamikita-gun, Aomori-ken (Japan)

2007-07-01

279

Crevice Repassivation Potential of Alloy 22 in High-Nitrate Dust Deliquescence Type Environments  

SciTech Connect

The nitrate ion (NO{sub 3}{sup -}) is an inhibitor for crevice corrosion of Alloy 22 (N06022) in chloride (Cl{sup -}) aqueous solutions. Naturally formed electrolytes may contain both chloride and nitrate ions. The higher the ratio R = [NO{sub 3}{sup -}]/[Cl{sup -}] in the solution the stronger the inhibition of crevice corrosion. Atmospheric desert dust contains both chloride and nitrate salts, generally based on sodium (Na{sup +}) and potassium (K{sup +}). Some of these salts may deliquescence at relatively low humidity at temperatures on the order of 150 C and higher. The resulting deliquescent brines are highly concentrated and especially rich in nitrate. Electrochemical tests have been performed to explore the anodic behavior of Alloy 22 in high chloride high nitrate electrolytes at temperatures as high as 150 C at ambient atmospheres. Naturally formed brines at temperatures higher than 120 C do not induce crevice corrosion in Alloy 22 because they contain high levels of nitrate. The inhibitive effect of nitrate on crevice corrosion is still active for temperatures higher than 100 C.

Lian, T; Gdowski, G E; Hailey, P D; Rebak, R B

2007-02-08

280

Pyrochemical process for extracting plutonium from an electrolyte salt  

DOEpatents

A pyrochemical process for extracting plutonium from a plutonium-bearing salt is disclosed. The process is particularly useful in the recovery of plutonium for electrolyte salts which are left over from the electrorefining of plutonium. In accordance with the process, the plutonium-bearing salt is melted and mixed with metallic calcium. The calcium reduces ionized plutonium in the salt to plutonium metal, and also causes metallic plutonium in the salt, which is typically present as finely dispersed metallic shot, to coalesce. The reduced and coalesced plutonium separates out on the bottom of the reaction vessel as a separate metallic phase which is readily separable from the overlying salt upon cooling of the mixture. Yields of plutonium are typically on the order of 95%. The stripped salt is virtually free of plutonium and may be discarded to low-level waste storage.

Mullins, L.J.; Christensen, D.C.

1982-09-20

281

Pyrochemical process for extracting plutonium from an electrolyte salt  

DOEpatents

A pyrochemical process for extracting plutonium from a plutonium-bearing salt is disclosed. The process is particularly useful in the recovery of plutonium from electrolyte salts which are left over from the electrorefining of plutonium. In accordance with the process, the plutonium-bearing salt is melted and mixed with metallic calcium. The calcium reduces ionized plutonium in the salt to plutonium metal, and also causes metallic plutonium in the salt, which is typically present as finely dispersed metallic shot, to coalesce. The reduced and coalesced plutonium separates out on the bottom of the reaction vessel as a separate metallic phase which is readily separable from the overlying salt upon cooling of the mixture. Yields of plutonium are typically on the order of 95%. The stripped salt is virtually free of plutonium and may be discarded to low-level waste storage.

Mullins, Lawrence J. (Los Alamos, NM); Christensen, Dana C. (Los Alamos, NM)

1984-01-01

282

Reduction of nitrate in Shewanella  

SciTech Connect

In the genome of Shewanella oneidensis, a napDAGHB gene cluster encoding periplasmic nitrate reductase (NapA) and accessory proteins and an nrfA gene encoding periplasmic nitrite reductase (NrfA) have been identified. These two systems seem to be atypical because the genome lacks genes encoding cytoplasmic membrane electron transport proteins, NapC for NAP and NrfBCD/NrfH for NRF, respectively. Here, we present evidence that reduction of nitrate to ammonium in S. oneidensis is carried out by these atypical systems in a two-step manner. Transcriptional and mutational analyses suggest that CymA, a cytoplasmic membrane electron transport protein, is likely to be the functional replacement of both NapC and NrfH in S. oneidensis. Surprisingly, a strain devoid of napB encoding the small subunit of nitrate reductase exhibited the maximum cell density sooner than the wild type. Further characterization of this strain showed that nitrite was not detected as a free intermediate in its culture and NapB provides a fitness gain for S. oneidensis to compete for nitrate in the environments. On the basis results from mutational analyses of napA, napB, nrfA and napBnrfA in-frame deletion mutants, we propose that NapB is able to favor nitrate reduction by routing electrons to NapA exclusively.

Gao, Haichun [University of Oklahoma; Yang, Zamin Koo [ORNL; Barua, Sumitra [University of Oklahoma, Norman; Reed, SB [Pacific Northwest National Laboratory (PNNL); Nealson, Kenneth H. [University of Southern California; Fredrikson, JK [Pacific Northwest National Laboratory (PNNL); Tiedje, James [Michigan State University, East Lansing; Zhou, Jizhong [University of Oklahoma

2009-01-01

283

Plutonium Test Plan ORNL-VNIIEF Collaboration  

Microsoft Academic Search

The goal of this test is to collect the cross correlation and HOS signatures from four detectors, arranged in a tetrahedron about different plutonium objects during ORNL\\/VNIIEF collaborative measurements in Sarov, Russia. The four detectors will be arranged in a tetrahedron with the plutonium object in the center of the tetrahedron. The following constraints about the detector geometry should be

L. G. Chiang; J. T. Mihalczo

2000-01-01

284

Accelerator mass spectrometry of plutonium isotopes  

Microsoft Academic Search

The feasibility of measuring plutonium isotope ratios by accelerator mass spectrometry has been demonstrated. Measurements on a test sample of known composition and on a blank showed that isotope ratios could be determined quantitatively, and that the present limit of detection by AMS is ? 106 atoms of plutonium. For 239Pu, this limit is at least two orders of magnitude

L. K. Fifield; R. G. Cresswell; M. L. di Tada; T. R. Ophel; J. P. Day; A. P. Clacher; S. J. King; N. D. Priest

1996-01-01

285

Disposal of Surplus Weapons Grade Plutonium  

Microsoft Academic Search

The Office of Fissile Materials Disposition is responsible for disposing of inventories of surplus US weapons-usable plutonium and highly enriched uranium as well as providing, technical support for, and ultimate implementation of, efforts to obtain reciprocal disposition of surplus Russian plutonium. On January 4, 2000, the Department of Energy issued a Record of Decision to dispose of up to 50

H. Alsaed; P. Gottlieb

2000-01-01

286

Plutonium Immobilization Project -- Robotic canister loading  

SciTech Connect

The Plutonium Immobilization Program (PIP) is a joint venture between the Savannah River Site, Lawrence Livermore National Laboratory, Argonne National Laboratory, and Pacific Northwest National Laboratory. When operational in 2008, the PIP will fulfill the nation's nonproliferation commitment by placing surplus weapons-grade plutonium in a permanently stable ceramic form.

Hamilton, L.

2000-04-28

287

Uses for plutonium: Weapons, reactors, and other  

SciTech Connect

This document begins with a introduction on criticality and supercriticality. Then, types and components, design and engineering, yields, and disassembly of nuclear weapons are discussed. Plutonium is evaluated as a reactor fuel, including neutronics and chemistry considerations. Finally, other uses of plutonium are analyzed.

Condit, R.H.

1994-05-01

288

Studies on Production of Sinterable Uranium Dioxide in a Small-Scale Batch Process Using Uranyl Nitrate Solution, Ammonum Polyuranate--Uranium Dioxide Method.  

National Technical Information Service (NTIS)

Slow precipitation from aqueous solutions of uranium nitrate with a concentration of about 60 to 65 g uranium per liter, using aqueous solutions of ammonia with a concentration of about 7 to 7.5 mol/liter, and at 60 exp 0 C, are good conditions for produc...

R. Wlodarski W. Dembinski R. Przytycka Z. Nowakowska

1978-01-01

289

Uranyl Nitrate Flow Loop  

SciTech Connect

The objectives of the work discussed in this report were to: (1) develop a flow loop that would simulate the purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant (NUCP); (2) develop a test plan that would simulate normal operation and disturbances that could be anticipated in an NUCP; (3) use the flow loop to test commercially available flowmeters for use as safeguards monitors; and (4) recommend a flowmeter for production-scale testing at an NUCP. There has been interest in safeguarding conversion plants because the intermediate products [uranium dioxide (UO{sub 2}), uranium tetrafluoride (UF{sub 4}), and uranium hexafluoride (UF{sub 6})] are all suitable uranium feedstocks for producing special nuclear materials. Furthermore, if safeguards are not applied virtually any nuclear weapons program can obtain these feedstocks without detection by the International Atomic Energy Agency (IAEA). Historically, IAEA had not implemented safeguards until the purified UF{sub 6} product was declared as feedstock for enrichment plants. H. A. Elayat et al. provide a basic definition of a safeguards system: 'The function of a safeguards system on a chemical conversion plant is in general terms to verify that no useful nuclear material is being diverted to use in a nuclear weapons program'. The IAEA now considers all highly purified uranium compounds as candidates for safeguarding. DOE is currently interested in 'developing instruments, tools, strategies, and methods that could be of use to the IAEA in the application of safeguards' for materials found in the front end of the nuclear fuel cycle-prior to the production of the uranium hexafluoride or oxides that have been the traditional starting point for IAEA safeguards. Several national laboratories, including Oak Ridge, Los Alamos, Lawrence Livermore, and Brookhaven, have been involved in developing tools or techniques for safeguarding conversion plants. This study was sponsored by the U.S. Department of Energy (DOE) NA-241, Office of Dismantlement and Transparency.

Ladd-Lively, Jennifer L [ORNL

2008-10-01

290

Nondestructive assay methods for solids containing plutonium  

SciTech Connect

Specific nondestructive assay (NDA) methods, e.g. calorimetry, coincidence neutron counting, singles neutron counting, and gamma ray spectrometry, were studied to provide the Savannah River Plant with an NDA method to measure the plutonium content of solid scrap (slag and crucible) generated in the JB-Line plutonium metal production process. Results indicate that calorimetry can be used to measure the plutonium content to within about 3% in 4 to 6 hours by using computerized equilibrium sample power predictive models. Calorimetry results confirm that a bias exists in the present indirect measurement method used to estimate the plutonium content of slag and crucible. Singles neutron counting of slag and crucible can measure plutonium to only +-30%, but coincidence neutron counting methods improve measurement precision to better than +-10% in less than ten minutes. Only four portions of a single slag and crucible sample were assayed, and further study is recommended.

Macmurdo, K.W.; Gray, L.W.; Gibbs, A.

1984-06-01

291

Separation of americium, curium, and plutonium from irradiated targets  

SciTech Connect

The Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL) processes highly irradiated targets for the Mark 42 program to separate Am, Cm, and Pu. The target feed material for each assembly was 3.3 kg of plutonium (78% {sup 239}Pu) that was irradiated at the Savannah River Site to yield approximately 100 g each of {sup 243}Am and {sup 244}Cm, and 100-g quantities of {sup 242}Pu for special DOE projects. The REDC has plans to process ten of these target assemblies over the next few years. The first assembly has been dissolved, and approximately 1/4 of this material has been used to test the processing flowsheet. Various aqueous processes developed at the REDC over the past years were utilized to dissolve the target segments, separate the bulk of the impurities from the transuranics, separate the plutonium from the transplutonium actinides, and separate the rare earth fission products from the Am-Cm. The separation of the Am-Cm products to the desired purity levels presented new processing challenges for REDC operations. Through a combination of precipitation and cation-exchange operations, an Am product containing part-per-million levels of Cm was obtained. Standard REDC processing techniques were used to prepare the products as oxides for shipment. Future processing will focus on the reduction of waste solutions, improvement of yields, and application of new technologies for improved processing.

Felker, L.K.; Benker, D.E.; Chattin, F.R. [Oak Ridge National Laboratory, TN (United States)] [and others

1995-04-01

292

Absorption spectra and speciation of plutonium(VI) with phosphate  

SciTech Connect

Plutonium(VI)-phosphate species in aqueous solution, at pH < 2.4, formed two species: PuO{sub 2}H{sub 2}PO{sub 4}{sup +} (characterized by an 835 nm absorption band) and the solid phase PuO{sub 2}(H{sub 2}PO{sub 4}){sub 2}. The stability constant {beta} for the PuO{sub 2}H{sub 2}PO{sub 4}{sup +} species was determined to be log {beta} = 2.1 {+-} 0.1 (ionic strength = 0.6--0.9 M) and log {beta}{sup T} = 2.6 {+-} 0.15 (zero ionic strength). Four Pu(VI)-phosphate species (absorption bands at 842, 846, 857, and 866 nm) formed at pH = 2.4 to 12.2 and are characterized by polynuclear behavior, the formation of precipitates, and colloidal properties. The 842 and 846 nm species are believed to be [PuO{sub 2}(HPO{sub 4}){sub m}]{sub n} and [PuO{sub 2}(NaPO{sub 4}){sub m}]{sub n}. The 857 and 866 nm species area as yet unidentified. The speciation of plutonium with phosphate is of interest to radionuclide migration studies because phosphate is present in many groundwaters and may be used as an actinide getter in nuclear waste disposal. An actinide getter is a complexing agent that forms insoluble phases with actinides, thereby reducing their migration.

Weger, H.T.; Reed, D.

1996-02-01

293

Acetonyltriphenyl-phospho-nium nitrate  

PubMed Central

Crystals of the title salt, C21H20OP+·NO3 ?, are composed of acetonyltriphenyl­phospho­nium cations and nitrate anions that mainly inter­act through electrostatic forces. The P atom in the cation has a slightly distorted tetra­hedral environment, with C—P—C angles ranging from 104.79?(7) to 112.59?(6)°. The sum of O—N—O angles of the nitrate anion is 359.99°, reflecting its trigonal–planar character. C—H?O hydrogen bonds help to consolidate the crystal packing.

Diop, Tidiane; Diop, Libasse; Kucerakova, Monika; Dusek, Michal

2013-01-01

294

REMOVAL OF LEGACY PLUTONIUM MATERIALS FROM SWEDEN  

SciTech Connect

U.S. Department of Energy’s National Nuclear Security Administration (NNSA) Office of Global Threat Reduction (GTRI) recently removed legacy plutonium materials from Sweden in collaboration with AB SVAFO, Sweden. This paper details the activities undertaken through the U.S. receiving site (Savannah River Site (SRS)) to support the characterization, stabilization, packaging and removal of legacy plutonium materials from Sweden in 2012. This effort was undertaken as part of GTRI’s Gap Materials Program and culminated with the successful removal of plutonium from Sweden as announced at the 2012 Nuclear Security Summit. The removal and shipment of plutonium materials to the United States was the first of its kind under NNSA’s Global Threat Reduction Initiative. The Environmental Assessment for the U.S. receipt of gap plutonium material was approved in May 2010. Since then, the multi-year process yielded many first time accomplishments associated with plutonium packaging and transport activities including the application of the of DOE-STD-3013 stabilization requirements to treat plutonium materials outside the U.S., the development of an acceptance criteria for receipt of plutonium from a foreign country, the development and application of a versatile process flow sheet for the packaging of legacy plutonium materials, the identification of a plutonium container configuration, the first international certificate validation of the 9975 shipping package and the first intercontinental shipment using the 9975 shipping package. This paper will detail the technical considerations in developing the packaging process flow sheet, defining the key elements of the flow sheet and its implementation, determining the criteria used in the selection of the transport package, developing the technical basis for the package certificate amendment and the reviews with multiple licensing authorities and most importantly integrating the technical activities with the Swedish partners.

Dunn, Kerry A. [Savannah River National Laboratory; Bellamy, J. Steve [Savannah River National Laboratory; Chandler, Greg T. [Savannah River National Laboratory; Iyer, Natraj C. [U.S. Department of Energy, National Nuclear Security Administration, Office of; Koenig, Rich E.; Leduc, D. [Savannah River National Laboratory; Hackney, B. [Savannah River National Laboratory; Leduc, Dan R. [Savannah River National Laboratory

2013-08-18

295

Estimating peak nitrate concentrations from annual nitrate loads  

NASA Astrophysics Data System (ADS)

The feasibility of adopting an empirical approach to predicting peak nitrate concentrations in water draining agricultural land is examined in the light of the relationships derived from leaching experiments on a range of soils, and from river data for England and Wales for the period 1974-1986. Well-fitted linear regressions were obtained of peak nitrate concentration in leachate on the annual load of leachable nitrate in the soil. The slopes to the regressions ranged in value from greater than 1.3 for measurements in shallow soils over limestone in a low rainfall area, to 0.25 for a well-structured clay soil with mole drainage in a high rainfall area. (A slope of 1.0 means that a load of 100 kg N ha -1 gives rise to a peak concentration of 100 mg N 1 -1). This range mainly reflected the ranges in soil water capacity and degree of preferential flow occurring during drainage. The slopes to the regressions for river waters were consistently smaller than those for clay soils in the same areas. The slopes for rivers draining mainly low-lying clay or chalk catchments in drier areas (Thames, Anglian and Southern Water Authority areas) were generally greater than those for rivers draining mainly wetter and more upland areas (South West and Welsh Water Authority areas). The differences between the slopes to the regressions for rivers could be partly accounted for by differences in average rainfall, suggesting possible effects from systematic differences in land use, soil structure and date of rewetting of soils in different climatic areas. The regressions indicated that peak concentrations in excess of the European Community limit (11.3 mg 1 -1 nitrate-N) might be associated with total nitrate loads in rivers draining clay catchments of 30 kg N hat in central and eastern England, or greater than 70 kg N ha -1 in Wales. The results indicate that the regressions for soils might form the basis of a catchment-scale model of nitrate leaching, provided that it is linked with a hydrogeological sub-model that accounts for the contribution to river discharge from upland and groundwater sources, and for the effects of different land uses on the timing of the peak nitrate concentrations.

Scholefield, D.; Lord, E. I.; Rodda, H. J. E.; Webb, B.

1996-11-01

296

Design of the improved plutonium canister assay system (IPCAS)  

Microsoft Academic Search

The improved Plutonium Canister Assay System (iPCAS) is designed to detect gross and partial defects in the declared plutonium content of plutonium and MOX storage canisters during transfer to storage and process areas of the MOX fuel fabrication facility in Kokkasho, Japan. In addition, an associated Gamma Isotopics System (GIS) will be used to confirm facility-declared plutonium isotopics with accuracy

M. E. Abhold; M. C. Baker; S. C. Bourret; P. J. Polk; Duc T. Vo

2001-01-01

297

Light water breeder reactor using a uranium-plutonium cycle  

Microsoft Academic Search

This patent describes a light water receptor (LWR) for breeding fissile material using a uranium-plutonium cycle. It comprises: a prebreeder section having plutonium fuel containing a Pu-241 component, the prebreeder section being operable to produce enriched plutonium having an increased Pu-241 component; and a breeder section for receiving the enriched plutonium from the prebreeder section, the breeder section being operable

A. Radkowsky; R. Chen

1990-01-01

298

Processing of Non-PFP Plutonium Oxide in Hanford Plants.  

National Technical Information Service (NTIS)

Processing of non-irradiated plutonium oxide, PuO2, scrap for recovery of plutonium values occurred routinely at Hanford's Plutonium Finishing Plant (PFP) in glovebox line operations. Plutonium oxide is difficult to dissolve, particularly if it has been h...

C. H. Delegard S. A. Jones

2011-01-01

299

Unexpected elastic softening in ? -plutonium  

NASA Astrophysics Data System (ADS)

Elastic-constant measurements on a Pu-2.4at.% Ga quasiisotropic polycrystal reveal remarkable elastic softening as temperature increases from ambient to 500K . Unexpected softening appears in both the bulk modulus B and the shear modulus G , thus in all quasiisotropic elastic stiffnesses such as the Young modulus and the Lamé constants. The dB/dT slope gives a (lattice) Grüneisen parameter ?=3.7 , much higher than a typical fcc-metallic-element value of 2.4±0.5 . Especially, this high ? from dB/dT measurements disagrees strongly with the ?=-0.26±0.5 from volume measurements. The dB/dT slope exceeds that measured previously at lower temperatures. Also, it exceeds that expected from high-temperature Debye-Waller-factor measurements. A two-level model used successfully previously to interpret this alloy’s unusually low thermal expansion also describes the large dB/dT . We comment on possible explanations for plutonium’s odd anharmonic behavior. These concepts include magnetism, 5f -electron localization-delocalization, and vibrational entropy. Our measurements on the Pu-Ga polycrystal agree remarkably well with a Kröner-theory average of previous measurements on a same-composition monocrystal.

Migliori, A.; Ledbetter, H.; Lawson, A. C.; Ramirez, A. P.; Miller, D. A.; Betts, J. B.; Ramos, M.; Lashley, J. C.

2006-02-01

300

A Study of the Stability and Characterization Plutonium Dioxide and Chemical Characterization [of] Rocky Flats and Los Alamos Plutonium-Containing Incinerator Ash  

SciTech Connect

In the presentation ''A Study of the Stability and Characterization of Plutonium Dioxide'', the authors discuss their recent work on actinide stabilities and characterization, in particular, plutonium dioxide PuO{sub 2}. Earlier studies have indicated that PuO{sub 2} has the fluorite structure of CaF{sub 2} and typical oxide semiconductor properties. However, detailed results on the bulk electronic structure of this important actinide oxide have not been available. The authors have used all-electron, full potential linear combinations Gaussian type orbitals fitting function (LCGTO-FF) method to study PuO{sub 2}. The LCGTO-FF technique characterized by its use of three independent GTO basis sets to expand the orbitals, charge density, and exchange-correlation integral kernels. Results will be presented on zero pressure using both the Hedin-Lundquist local density approximation (LDA) model or the Perdew-Wang generalized gradient approximation (GGA) model. Possibilities of different characterizations of PuO{sub 2} will be explored. The paper ''Chemical Characterization Rocky Flats and Los Alamos Plutonium-Containing Incinerator Ash'' describes the results of a comprehensive study of the chemical characteristics of virgin, calcined and fluorinated incinerator ash produced at the Rocky Flats Plant and at the Los Alamos National Laboratory prior to 1988. The Rocky Flats and Los Alamos virgin, calcined, and fluorinated ashes were also dissolved using standard nitrate dissolution chemistry. Corresponding chemical evaluations were preformed on the resultant ash heel and the results compared with those of the virgin ash. Fluorination studies using FT spectroscopy as a diagnostic tool were also performed to evaluate the chemistry of phosphorus, sulfur, carbon, and silicon containing species in the ash. The distribution of plutonium and other chemical elements with the virgin ash, ash heel, fluorinated ash, and fluorinated ash heel particulates were studied in detail using microprobe analysis. Some of the more interesting results of these investigations are presented.

Ray, A.K.; Boettger, J.C.; Behrens, Robert G.

1999-11-29

301

New Synthesis of Fluorine Nitrate.  

National Technical Information Service (NTIS)

The reaction of NF4(+)SbF6(-) with alkali metal nitrates in either CH3CN or SO2 solution at low temperature produces FONO2 in quantitative yield. Attempts were unsuccessful to prepare FONO from NF4SbF6 and KNO2 in an analogous manner.

B. Hoge K. O. Christe

2000-01-01

302

Toxicity Studies of Triaminoguanidine Nitrate.  

National Technical Information Service (NTIS)

The acute toxicity of triaminoguanidine nitrate (TAGN) has been studied. The LD(50) of TAGN in mice was 3.65 g/kg with 95% confidence limits of 3.54 - 3.76 g/kg. At IV doses of 50-200 mg/kg given to anesthetized dogs, TAGN caused a slightly decreased hear...

R. A. Davis C. T. Olson R. N. Terpolilli K. C. Back

1977-01-01

303

Nitrate accumulation in forage brassicas  

Microsoft Academic Search

Previous research has shown that the application of fertilizer nitrogen (N) can lead to an accumulation of nitrate nitrogen (NO3-N) in forage brassicas, particularly when N application rates exceed that required to obtain maximum crop yield. However, there are no data examining the effect of timing of fertilizer application on NO3-N accumulation. An experiment was established in 2009 with four

AL Fletcher; E Chakwizira

2012-01-01

304

Organic Nitrates from Isoprene during BEARPEX-2009  

NASA Astrophysics Data System (ADS)

Organic nitrates transport nitrogen oxides, and impact ozone formation. A subset of organic nitrates, hydroxy-nitrates from isoprene (sum of isomers), methyl vinyl ketone, and methacrolein, were measured using chemical ionization mass spectrometry during BEARPEX 2009. These measurements are used to assess the contribution of isoprene to the fraction of total alkyl nitrates observed over the ponderosa pine forest plantation. Implications for the mechanism of isoprene oxidation in the presence of nitrogen oxides are discussed.

Beaver, M. R.; St. Clair, J.; Paulot, F.; Spencer, K. M.; Crounse, J.; Min, K.; Pusede, S. E.; Lafranchi, B. W.; Browne, E. C.; Cohen, R. C.; Wennberg, P. O.

2010-12-01

305

A Novel Chemical Nitrate Destruction Process  

SciTech Connect

Nitrates represent one of the most significant pollutant discharged to the Baltic Sea by the Sliiamae hydrometallurgical plant. This article contains a brief overview of the existing nitrate destruction technologies followed by the description of a new process developed by the authors. The new chemical process for nitrate destruction is cost effective and simple to operate. It converts the nitrate to nitrogen gas which goes to the atmosphere.

Dziewinski, J.; Marczak, S.

1999-03-01

306

Plasma nitrate and nitrite are increased by a high nitrate supplement, but not by high nitrate foods in older adults  

PubMed Central

Little is known about the effect of dietary nitrate on the nitrate/nitrite/NO (nitric oxide) cycle in older adults. We examined the effect of a 3-day control diet vs. high nitrate diet, with and without a high nitrate supplement (beetroot juice), on plasma nitrate and nitrite kinetics, and blood pressure using a randomized four period cross-over controlled design. We hypothesized that the high nitrate diet would show higher levels of plasma nitrate/nitrite and blood pressure compared to the control diet, which would be potentiated by the supplement. Participants were eight normotensive older men and women (5 female, 3 male, 72.5±4.7 yrs) with no overt disease or medications that affect NO metabolism. Plasma nitrate and nitrite levels and blood pressure were measured prior to and hourly for 3 hours after each meal. The mean daily changes in plasma nitrate and nitrite were significantly different from baseline for both control diet+supplement (p<0.001 and =0.017 for nitrate and nitrite, respectively) and high nitrate diet+supplement (p=0.001 and 0.002), but not for control diet (p=0.713 and 0.741) or high nitrate diet (p=0.852 and 0.500). Blood pressure decreased from the morning baseline measure to the three 2 hr post-meal follow-up time-points for all treatments, but there was no main effect for treatment. In healthy older adults, a high nitrate supplement consumed at breakfast elevated plasma nitrate and nitrite levels throughout the day. This observation may have practical utility for the timing of intake of a nitrate supplement with physical activity for older adults with vascular dysfunction.

Miller, Gary D.; Marsh, Anthony P.; Dove, Robin W.; Beavers, Daniel; Presley, Tennille; Helms, Christine; Bechtold, Erika; King, S. Bruce; Kim-Shapiro, Daniel

2012-01-01

307

Stability indicating HPLC-method for the determination of econazole nitrate in cream and lotion formulations.  

PubMed

A simple, fast HPLC-method for the determination of econazole nitrate in cream (Pevaryl, Pevisone) and lotion formulations (based on polyethylenic oleic glycerides and mono/di-stearic esters of ethylene- and polyethylene glycol) is described. The method is stability indicating as well as linear (range 5-15 mg econazole nitrate/g) and shows a good recovery (98.7-100.2%) and a good reproducibility (cv less than 1%, n = 10). The chromatographic separation is achieved on a RP-18 column using methanol/aqueous ammoniumcarbonate solution/tetrahydrofurane as the mobile phase. Quantification of the chromatograms is done by internal standard method using peak areas. PMID:6540569

Christinat, R; Zulliger, H W

1984-01-01

308

Nitration of Naphthol: A Laboratory Experiment.  

ERIC Educational Resources Information Center

Products of nitrations, upon distillation or steam distillation, may produce dermatitis in some students. A procedure for nitration of beta-naphthol producing a relatively non-volatile product not purified by steam distillation is described. Nitration of alpha-naphthol by the same procedure yields Martius Yellow dye which dyes wool yellow or…

Mowery, Dwight F.

1982-01-01

309

21 CFR 172.160 - Potassium nitrate.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-04-01 true Potassium nitrate. 172.160 Section 172.160 Food...CONSUMPTION Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing agent...

2010-01-01

310

21 CFR 172.160 - Potassium nitrate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Potassium nitrate. 172.160 Section 172.160 Food...CONSUMPTION Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing agent...

2013-04-01

311

21 CFR 172.160 - Potassium nitrate.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Potassium nitrate. 172.160 Section 172.160 Food...CONSUMPTION Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing agent...

2009-04-01

312

DO ORGANIC FARMING PRACTICES REDUCE NITRATE LEACHING?  

Microsoft Academic Search

Agriculture is a contributor of nitrate to natural waters and there is concern about the excess nitrogen burden loadings from agriculture on natural waters. Agricultural practices that reduce nitrate leaching from arable land are needed. It is postulated by certain groups that organic farming practices reduce nitrate leaching among other environmental benefits. The objectives of this paper are: (1) to

Holger Kirchmann; Lars Bergström

2001-01-01

313

The position of nitrate respiration in evolution.  

PubMed

Egami's hypothesis that oxygen respiration evolved from nitrate respiration, and this from nitrate fermentation, is not accepted. The reasons are: (1) Presumably there was no nitrate before O2 in the biosphere. (2) On mechanistic grounds, respiration (oxidative phosphorylation) is to be derived directly from photosynthesis (photosynthetic phosphorylation) rather than from any form of fermentation. PMID:917501

Broda, E

1977-08-01

314

Removal of nitrates from groundwater by electrocoagulation  

Microsoft Academic Search

In this study, coagulation and electrocoagulation processes were compared with regard to their respective efficiencies as to the removal of nitrates from water. The results indicate that electrocoagulation is an effective technology for nitrate removal because nitrate anions preferentially adsorb onto the surfaces of growing metal-hydroxide precipitates. Other similar results were observed when using iron or aluminium electrodes whenever coagulation

Engracia Lacasa; Pablo Cañizares; Cristina Sáez; Francisco J. Fernández; Manuel A. Rodrigo

2011-01-01

315

COGEMA Experience in Uranous Nitrate Preparation  

Microsoft Academic Search

Separation and purification of plutonium by PUREX process is based on a sequence of extraction and back extraction which requires reducing plutonium Pu IV (extractable form) into Pu III (inextractable form) Different reducers can be used to reduce Pu IV into Pu III. Early plants such as that for Magnox fuel at Sellafield used ferrous sulfamate while UP 1 at

E. Tison; Ph. Bretault

2006-01-01

316

Plutonium Immobilization Can Loading Conceptual Design  

SciTech Connect

'The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

Kriikku, E.

1999-05-13

317

Weapons-grade plutonium dispositioning. Volume 4. Plutonium dispositioning in light water reactors  

SciTech Connect

This study is in response to a request by the Reactor Panel Subcommittee of the National Academy of Sciences (NAS) Committee on International Security and Arms Control (CISAC) to evaluate the feasibility of using plutonium fuels (without uranium) for disposal in existing conventional or advanced light water reactor (LWR) designs and in low temperature/pressure LWR designs that might be developed for plutonium disposal. Three plutonium-based fuel forms (oxides, aluminum metallics, and carbides) are evaluated for neutronic performance, fabrication technology, and material and compatibility issues. For the carbides, only the fabrication technologies are addressed. Viable plutonium oxide fuels for conventional or advanced LWRs include plutonium-zirconium-calcium oxide (PuO{sub 2}-ZrO{sub 2}-CaO) with the addition of thorium oxide (ThO{sub 2}) or a burnable poison such as erbium oxide (Er{sub 2}O{sub 3}) or europium oxide (Eu{sub 2}O{sub 3}) to achieve acceptable neutronic performance. Thorium will breed fissile uranium that may be unacceptable from a proliferation standpoint. Fabrication of uranium and mixed uranium-plutonium oxide fuels is well established; however, fabrication of plutonium-based oxide fuels will require further development. Viable aluminum-plutonium metallic fuels for a low temperature/pressure LWR include plutonium aluminide in an aluminum matrix (PuAl{sub 4}-Al) with the addition of a burnable poison such as erbium (Er) or europium (Eu). Fabrication of low-enriched plutonium in aluminum-plutonium metallic fuel rods was initially established 30 years ago and will require development to recapture and adapt the technology to meet current environmental and safety regulations. Fabrication of high-enriched uranium plate fuel by the picture-frame process is a well established process, but the use of plutonium would require the process to be upgraded in the United States to conform with current regulations and minimize the waste streams.

Sterbentz, J.W.; Olsen, C.S.; Sinha, U.P.

1993-06-01

318

Spectrophotometric determination of plutonium-239 based on the spectrum of plutonium(III) chloride  

SciTech Connect

This report describes a spectrophotometric method for determining plutonium-239 (Pu-239) based on the spectrum of Pu(III) chloride. The authors used the sealed-reflux technique for the dissolution of plutonium oxide with hydrochloric acid (HCl) and small amounts of nitric and hydrofluoric acids. To complex the fluoride, they added zirconium, and to reduce plutonium to Pu(III), they added ascorbic acid. They then adjusted the solution to a concentration of 2 M HCl and measured the absorbances at five wavelengths of the Pu(III) chloride spectrum. This spectrophotometric determination can also be applied to samples of plutonium metal dissolved in HCl.

Temer, D.J.; Walker, L.F.

1994-07-01

319

What is plutonium stabilization, and what is safe storage of plutonium?  

SciTech Connect

The end of the cold war has resulted in the shutdown of nuclear weapons production and the start of dismantlement of significant numbers of nuclear weapons. This, in turn, is creating an inventory of plutonium requiring interim and long-term storage. A key question is, ``What is required for safe, multidecade, plutonium storage?`` The requirements for storage, in turn, define what is needed to stabilize the plutonium from its current condition into a form acceptable for interim and long-term storage. Storage requirements determine if research is required to (1) define required technical conditions for interim and long-term storage and (2) develop or improve current stabilization technologies. Storage requirements depend upon technical, policy, and economic factors. The technical issues are complicated by several factors. Plutonium in aerosol form is highly hazardous. Plutonium in water is hazardous. The plutonium inventory is in multiple chemical forms--some of which are chemically reactive. Also, some of the existing storage forms are clearly unsuitable for storage periods over a few years. Gas generation by plutonium compounds complicates storage: (1) all plutonium slowly decays creating gaseous helium and (2) the radiation from plutonium decay can initiate many chemical reactions-some of which generate significant quantities of gases. Gas generation can pressurize sealed storage packages. Last nuclear criticality must be avoided.

Forsberg, C.W.

1995-06-29

320

Sorption/Desorption Interactions of Plutonium with Montmorillonite  

NASA Astrophysics Data System (ADS)

Plutonium (Pu) release to the environment through nuclear weapon development and the nuclear fuel cycle is an unfortunate legacy of the nuclear age. In part due to public health concerns over the risk of Pu contamination of drinking water, predicting the behavior of Pu in both surface and sub-surface water is a topic of continued interest. Typically it was assumed that Pu mobility in groundwater would be severely restricted, as laboratory adsorption studies commonly show that naturally occurring minerals can effectively remove plutonium from solution. However, evidence for the transport of Pu over significant distances at field sites highlights a relative lack of understanding of the fundamental processes controlling plutonium behavior in natural systems. At several field locations, enhanced mobility is due to Pu association with colloidal particles that serve to increase the transport of sorbed contaminants (Kersting et al., 1999; Santschi et al., 2002, Novikov et al., 2006). The ability for mineral colloids to transport Pu is in part controlled by its oxidation state and the rate of plutonium adsorption to, and desorption from, the mineral surface. Previously we have investigated the adsorption affinity of Pu for montmorillonite colloids, finding affinities to be similar over a wide range of Pu concentrations. In the present study we examine the stability of adsorbed Pu on the mineral surface. Pu(IV) at an initial concentration of 10-10 M was pre-equilibrated with montmorillonite in a background electrolyte at pH values of 4, 6 and 8. Following equilibration, aliquots of the suspensions were placed in a flow cell and Pu-free background electrolyte at the relevant pH was passed through the system. Flow rates were varied in order to investigate the kinetics of desorption and hence gain a mechanistic understanding of the desorption process. The flow cell experiments demonstrate that desorption of Pu from the montmorillonite surface cannot be modeled as a simple first order process. Furthermore, a pH dependence was observed, with less desorbed at pH 4 compared to pH 8. We suggest the pH dependence is likely controlled by reoxidation of Pu(IV) to Pu(V) and aqueous speciation. We will present models used to describe desorption behavior and discuss the implications for Pu transport. References: Kersting, A.B.; Efurd, D.W.; Finnegan, D.L.; Rokop, D.J.; Smith, D.K.; Thompson J.L. (1999) Migration of plutonium in groundwater at the Nevada Test Site, Nature, 397, 56-59. Novikov A.P.; Kalmykov, S.N.; Utsunomiya, S.; Ewing, R.C.; Horreard, F.; Merkulov, A.; Clark, S.B.; Tkachev, V.V.; Myasoedov, B.F. (2006) Colloid transport of plutonium in the far-field of the Mayak Production Association, Russia, Science, 314, 638-641. Santschi, P.H.; Roberts, K.; Guo, L. (2002) The organic nature of colloidal actinides transported in surface water environments. Environ. Sci. Technol., 36, 3711-3719. This work was funded by U. S. DOE Office of Biological & Environmental Sciences, Subsurface Biogeochemistry Research Program, and performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Security, LLC under Contract DE-AC52-07NA27344. LLNL-ABS-570161

Begg, J.; Zavarin, M.; Zhao, P.; Kersting, A. B.

2012-12-01

321

Effect of dissolved organic matter on nitrate-nitrogen removal by anion exchange resin and kinetics studies.  

PubMed

The effects of dissolved organic matter (DOM) on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins. With the increase of gallic acid concentration from 0 to 400 mg/L, the adsorption amount of nitrate-nitrogen on the commercial resins, including D201, Purolite A 300 (A300) and Purolite A 520E (A520E), would significantly decrease. However, the presence of tannin acid has little impact on nitrate-nitrogen adsorption on them.Compared to D201 and A300 resins, A520E resin exhibited more preferable adsorption ability toward nitrate-nitrogen in the presence of competing organic molecules, such as gallic acid and tannin acid at greater levels in aqueous solution. Attractively, the equilibrium data showed that the adsorption isotherm of nitrate-nitrogen on A520E resin was in good agreement with Langmuir and Freundlich equations. The rate parameters for the intra particle diffusion have been estimated for the different initial concentrations. In batch adsorption processes, nitrate-nitrogen diffuse in porous adsorbent and rate process usually depends on t1/2 rather than the contact time. The pseudo first- and the second-order kinetic models fit better for nitrate-nitrogen adsorption onto A520E resin. The observations reported herein illustrated that A520E resin will be an excellent adsorbent for enhanced removal of nitrate-nitrogen from contaminated groundwater. PMID:23586305

Song, Haiou; Yao, Zhijian; Wang, Mengqiao; Wang, Jinnan; Zhu, Zhaolian; Li, Aimin

2013-01-01

322

Opportunities in Plutonium Metallurgical Research  

SciTech Connect

This is an exciting time to be involved in plutonium metallurgical research. Over the past few years, there have been significant advances in our understanding of the fundamental materials science of this unusual metal, particularly in the areas of self-irradiation induced aging of Pu, the equilibrium phase diagram, the homogenization of {delta}-phase alloys, the crystallography and morphology of the {alpha}'-phase resulting from the isothermal martensitic phase transformation, and the phonon dispersion curves, among many others. In addition, tremendous progress has been made, both experimentally and theoretically, in our understanding of the condensed matter physics and chemistry of the actinides, particularly in the area of electronic structure. Although these communities have made substantial progress, many challenges still remain. This brief overview will address a number of important challenges that we face in fully comprehending the metallurgy of Pu with a specific focus on aging and phase transformations. (author)

Schwartz, Adam J. [Lawrence Livermore National Laboratory, Livermore, California (United States)

2007-07-01

323

Nitrated fatty acids: Synthesis and measurement  

PubMed Central

Nitrated fatty acids are the product of nitrogen dioxide reaction with unsaturated fatty acids. The discovery of peroxynitrite and peroxidase-induced nitration of biomolecules led to the initial reports of endogenous nitrated fatty acids. These species increase during ischemia reperfusion, but concentrations are often at or near the limits of detection. Here, we describe multiple methods for nitrated fatty acid synthesis, sample extraction from complex biological matrices, and a rigorous method of qualitative and quantitative detection of nitrated fatty acids by LC-MS. In addition, optimized instrument conditions and caveats regarding data interpretation are discussed.

Woodcock, Steven R.; Bonacci, Gustavo; Gelhaus, Stacy L.; Schopfer, Francisco J.

2012-01-01

324

ENDF/B-VII.0, ENDF/B-VI, JEFF-3.1, AND JENDL-3.3 RESULTS FOR UNREFLECTED PLUTONIUM SOLUTIONS AND MOX LATTICES (U)  

SciTech Connect

Previous studies have indicated that ENDF/B-VII preliminary releases {beta}-2 and {beta}-3, predecessors to the recent initial release of ENDF/B-VII.0, produce significantly better overall agreement with criticality benchmarks than does ENDF/B-VI. However, one of those studies also suggests that improvements still may be needed for thermal plutonium cross sections. The current study substantiates that concern by examining criticality benchmarks for unreflected spheres of plutonium-nitrate solutions and for slightly and heavily borated mixed-oxide (MOX) lattices. Results are presented for the JEFF-3.1 and JENDL-3.3 nuclear data libraries as well as ENDF/B-VII.0 and ENDF/B-VI. It is shown that ENDF/B-VII.0 tends to overpredict reactivity for thermal plutonium benchmarks over at least a portion of the thermal range. In addition, it is found that additional benchmark data are needed for the deep thermal range.

MOSTELLER, RUSSELL D. [Los Alamos National Laboratory

2007-02-09

325

Design-only conceptual design report: Plutonium Immobilization Plant  

SciTech Connect

This design-only conceptual design report was prepared to support a funding request by the Department of Energy Office of Fissile Materials Disposition for engineering and design of the Plutonium Immobilization Plant, which will be used to immobilize up to 50 tonnes of surplus plutonium. The Plutonium Immobilization Plant will be located at the Savannah River Site pursuant to the Surplus Plutonium Disposition Final Environmental Impact Statement Record of Decision, January 4, 2000. This document reflects a new facility using the ceramic immobilization technology and the can-in-canister approach. The Plutonium Immobilization Plant accepts plutonium oxide from pit conversion and plutonium and plutonium oxide from non-pit sources and, through a ceramic immobilization process, converts the plutonium into mineral-like forms that are subsequently encapsulated within a large canister of high-level waste glass. The final immobilized product must make the plutonium as inherently unattractive and inaccessible for use in nuclear weapons as the plutonium in spent fuel from commercial reactors; it must also be suitable for geologic disposal. Plutonium immobilization at the Savannah River Site uses a new building, the Plutonium Immobilization Plant, which will receive and store feed materials, convert non-pit surplus plutonium to an oxide form suitable for the immobilization process, immobilize the plutonium oxide in a titanate-based ceramic form, place cans of the plutonium-ceramic forms into magazines, and load the magazines into a canister. The existing Defense Waste Processing Facility is used for the pouring of high-level waste glass into the canisters. The Plutonium Immobilization Plant uses existing Savannah River Site infrastructure for analytical laboratory services, waste handling, fire protection, training, and other support utilities and services. This design-only conceptual design report also provides the cost for a Plutonium Immobilization Plant which would process and immobilize 17 tonnes of plutonium in ten years. The project schedule for either case is shown in a table.

DiSabatino, A A

2000-05-01

326

Oxidant supply and aqueous photochemical SOA formation in cloud droplets and aqueous aerosol  

NASA Astrophysics Data System (ADS)

Many recent laboratory, field and model studies point to significant contributions to the total secondary organic aerosol (SOA) budget from aqueous phase reactions in cloud droplets and aqueous aerosol particles. Laboratory studies of the photochemical oxidation of glyoxal and methylglyoxal in the aqueous phase show a strong dependence on the initial concentration of dissolved organics, with preferential formation of large molecules (dimers, oligomers) at the high concentrations found in ambient deliquesced aerosol particles. In such experimental studies OH radicals are produced in the aqueous phase (via hydrogen peroxide photolysis) and OH radical is assumed to be the major oxidant. An explicit aqueous photooxidation mechanism has been validated, in part, based on the observed temporal evolution of organic intermediates and products in these experiments. In this work, this mechanism was incorporated into multiphase process models (box, cloud parcel) in order to further explore aqueous SOA formation in dilute cloud droplets and concentrated aerosol particles. We found that the predicted SOA mass in both aqueous phases can be comparable despite the much lower liquid water content in aerosols, where oligomer formation is favored. Direct uptake from the gas phase was the largest source of OH radicals in the aqueous phase. In-situ production through the Fenton reaction (Fe), hydrogen peroxide and nitrate photolysis were minor sources. Since phase transfer is slower than the OH(aq) consumption by organics, modeled OH(aq) concentrations were smaller by 1-2 orders of magnitude than predicted based on thermodynamic equilibrium. Our model studies suggest that, unless there are substantial additional sources of OH radical in the aqueous phase, aqueous SOA formation will be oxidant limited. Since the phase transfer rate is a function of the drop (or particle) surface area, aqueous SOA formation may occur preferentially at or near the drop/particle surface (e.g., be surface-limited) and thus add SOA mass preferentially to particle populations with higher surface/volume ratios. These model results will be compared and contrasted with aqueous sulfate formation. We will discuss our findings in the context of ambient data that might suggest a preferential aqueous SOA formation in smaller (high surface/volume) particles. We will also highlight current gaps in our understanding of oxidant production and cycling in the aqueous phase that might influence our results and change dependencies on bulk water volume versus surface area.

Turpin, B. J.; Ervens, B.; Lim, Y. B.

2012-12-01

327

Preparation of thin ceramic films via an aqueous solution route  

DOEpatents

A new chemical method of forming thin ceramic films has been developed. An aqueous solution of metal nitrates or other soluble metal salts and a low molecular weight amino acid is coated onto a substrate and pyrolyzed. The amino acid serves to prevent precipitation of individual solution components, forming a very viscous, glass-like material as excess water is evaporated. Using metal nitrates and glycine, the method has been demonstrated for zirconia with various levels of yttria stabilization, for lanthanum-strontium chromites, and for yttrium-barium-copper oxide superconductors on various substrates.

Pederson, Larry R. (Kennewick, WA); Chick, Lawrence A. (Richland, WA); Exarhos, Gregory J. (Richland, WA)

1989-01-01

328

Tyrosine nitration in prostaglandin H(2) synthase.  

PubMed

In this study, we investigated the effects of various nitrogen oxide (NO(x)) species on the extent of prostaglandin H(2) synthase-1 (PGHS-1) nitration in purified protein and in vascular smooth muscle cells. We also examined PGHS-1 activity under these conditions and found the degree of nitration to correlate inversely with enzyme activity. In addition, since NO(x) species are thought to invoke damage during the pathogenesis of atherosclerosis, we examined human atheromatous tissue for PGHS-1 nitration. Both peroxynitrite and tetranitromethane induced Tyr nitration of purified PGHS-1, whereas 1-hydroxy-2-oxo-3-(N-methyl-aminopropyl)-3-methyl-1-triazene (NOC-7; a nitric oxide-releasing compound) did not. Smooth muscle cells treated with peroxynitrite showed PGHS-1 nitration. The extent of nitration by specific NO(x) species was determined by electrospray ionization mass spectrometry. Tetranitromethane was more effective than peroxynitrite, NOC-7, and nitrogen dioxide at nitrating a tyrosine-containing peptide (12%, 5%, 1%, and <1% nitration, respectively). Nitrogen dioxide and, to a lesser extent, peroxynitrite, induced dityrosine formation. Using UV/Vis spectroscopy, it was estimated that the reaction of PGHS-1 with excess peroxynitrite yielded two nitrated tyrosines/PGHS-1 subunit. Finally, atherosclerotic tissue obtained from endarterectomy patients was shown to contain nitrated PGHS-1. Thus, prolonged exposure to elevated levels of peroxynitrite may cause oxidative damage through tyrosine nitration. PMID:12364556

Deeb, Ruba S; Resnick, Matthew J; Mittar, Dev; McCaffrey, Timothy; Hajjar, David P; Upmacis, Rita K

2002-10-01

329

Deconstructing nitrate isotope dynamics in aquifers  

NASA Astrophysics Data System (ADS)

The natural abundance N and O stable isotope ratios of nitrate provide an invaluable tool to differentiate N sources to the environment, track their dispersal, and monitor their attenuation by biological transformations. The interpretation of patterns in isotope abundances relies on knowledge of the isotope ratios of the source end-members, as well as on constraints on the isotope discrimination imposed on nitrate by respective biological processes. Emergent observations from mono-culture experiments of denitrifying bacteria reveal nitrate fractionation trends that appear at odds with trends ascribed to denitrification in soils and aquifers. This discrepancy raises the possibility that additional biological N transformations may be acting in tandem with denitrification. Here, the N and O isotope enrichments associated with nitrate removal by denitrification in aquifers are posited to bear evidence of coincident biological nitrate production - from nitrification and/or from anammox. Simulations are presented from a simple time-dependent one-box model of a groundwater mass ageing that is subject to net nitrate loss by denitrification with coincident nitrate production by nitrification or anammox. Within boundary conditions characteristic of freshwater aquifers, the apparent slope of the parallel enrichments in nitrate N and O isotopes associated with net N loss to denitrification can vary in proportion to the nitrate added simultaneous by oxidative processes. Pertinent observations from nitrate plumes in suboxic to anoxic aquifers are examined to validate this premise. In this perspective, nitrate isotope distributions suggest that we may be missing important N fluxes inherent to most aquifers.

Granger, J.

2012-12-01

330

Plutonium Test Plan ORNL-VNIIEF Collaboration.  

National Technical Information Service (NTIS)

The goal of this test is to collect the cross correlation and HOS signatures from four detectors, arranged in a tetrahedron about different plutonium objects during ORNL/VNIIEF collaborative measurements in Sarov, Russia. The four detectors will be arrang...

L. G. Chiang J. T. Mihalezo

2000-01-01

331

Leaching behavior of particulate plutonium oxide  

SciTech Connect

Different size cuts of /sup 238/PuO/sub 2/ particles were mixed with deionized water at two temperatures in a shaker bath. The gross plutonium concentration in the water was measured, as well as that portion of the plutonium retained on a 0.1-..mu..m pore filter. The concentration of the plutonium released was primarily a function of the surface area of the particles. The release rate of plutonium into the water for the size cut with particles having diameters between 30 and 20 ..mu..m was 3 ng/m/sup 2//s; this rate is within the range observed in past experiments involving aquatic environments. The amount of material retained by the 0.1-..mu..m filters decreased with increasing time, suggesting that size reduction or removal processes occurred. 6 refs., 3 figs., 9 tabs.

Kosiewicz, S.T.; Heaton, R.C.

1985-08-01

332

Design and evaluation of plutonium electrorefining cells  

SciTech Connect

A plutonium electrorefining cell was designed for stationary furnace operation. This cell and the LANL electrorefining cell were evaluated. Results of this evaluation and comparison to existing production electrorefining at Rocky Flats are presented.

Not Available

1987-01-01

333

Plutonium Sphere Reflected by Reflected by Beryllium.  

National Technical Information Service (NTIS)

This experiment with an alpha-phase plutonium sphere reflected by beryllium was performed using the Planet critical assembly at the Los Alamos Critical Experiments Facility (LACEF). The beryllium reflector consisted of a pair of inner and outer hemisphere...

D. Loaiza J. Hutchinson

2013-01-01

334

Phase diagram of ammonium nitrate  

NASA Astrophysics Data System (ADS)

Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

Dunuwille, M.; Yoo, C. S.

2014-05-01

335

Plutonium-238 processing at Savannah River Plant  

SciTech Connect

Plutonium-238 is produced by irradiating NpO/sub 2/-Al cermet slugs or tubes with neutrons. The neptunium-237 is produced as a by-product when natural or enriched uranium is irradiated with neutrons. The neptunium is separated by solvent extraction and ion exchange and precipitated as neptunium oxalate. Neptunium oxalate is calcined to neptunium oxide and fabricated into targets for irradiation. The irradiation conditions are controlled to produce plutonium with 80 to 90 wt % /sup 238/Pu.

Burney, G.A.

1983-01-01

336

Explosive properties of reactor?grade plutonium  

Microsoft Academic Search

The following discussion focuses on the question of whether a terrorist organization or a threshold state could make use of plutonium recovered from light?water?reactor fuel to construct a nuclear explosive device having a significantly damaging yield. Questions persist in some nonproliferation policy circles as to whether a bomb could be made from reactor?grade plutonium of high burn?up, and if so,

J. Carson Marka

1993-01-01

337

Characterization of Delta Phase Plutonium Metal  

Microsoft Academic Search

The FB-Line facility has developed the capability to recast plutonium metal using an M-18 reduction furnace with a new casting chamber. Plutonium metal is recast by charging a standard FB-Line magnesia crucible and placing the charge in the casting chamber. The loaded casting chamber is raised into the M-18 reduction furnace and sealed against the furnace head using a copper

Rudisill

2000-01-01

338

Plutonium scrap multiplicity counter operation manual  

Microsoft Academic Search

This manual describes the design features and performance and operating characteristics for the plutonium scrap multiplicity counter (PSMC). It counts neutron multiplicities to quantitatively assay plutonium in many forms, including impure scrap and waste. Monte Carlo neutronic calculations were used to design the high-efficiency (55%) detector using eighty ³He tubes in a high-density polyethylene body. The new multiplicity shift-register electronics

H. O. Menlove; J. Baca; M. S. Krick; K. E. Kroncke; D. G. Langner

1993-01-01

339

Plutonium scrap multiplicity counter operation manual  

Microsoft Academic Search

This manual describes the design features and performance and operating characteristics for the plutonium scrap multiplicity counter (PSMC). It counts neutron multiplicities to quantitatively assay plutonium in many forms, including impure scrap and waste. Monte Carlo neutronic calculations were used to design the high-efficiency (55%) detector using eighty [sup 3]He tubes in a high-density polyethylene body. The new multiplicity shift-register

H. O. Menlove; J. Baca; M. S. Krick; K. E. Kroncke; D. G. Langner

1993-01-01

340

Future role of plutonium technology in society  

SciTech Connect

Until the fall of the Berlin Wall, there was a very clear programmatic use of plutonium: supporting the nuclear deterrent. Since the breakup of the Soviet Union, bilateral agreements concerning the cessation of nuclear testing and the dismantlement of large portions of the nuclear weapon stockpiles by the United States and the states of the former Soviet Union have resulted in new requirements concerning the management and disposition of nuclear materials. This report describes current issues pertaining to the requirements for plutonium management.

Christensen, D.C.; Matthews, R.B.; Trapp, T.J. [Los Alamos National Lab., NM (United States)

1995-12-31

341

High performance ammonium nitrate propellant  

NASA Technical Reports Server (NTRS)

A high performance propellant having greatly reduced hydrogen chloride emission is presented. It is comprised of: (1) a minor amount of hydrocarbon binder (10-15%), (2) at least 85% solids including ammonium nitrate as the primary oxidizer (about 40% to 70%), (3) a significant amount (5-25%) powdered metal fuel, such as aluminum, (4) a small amount (5-25%) of ammonium perchlorate as a supplementary oxidizer, and (5) optionally a small amount (0-20%) of a nitramine.

Anderson, F. A. (inventor)

1979-01-01

342

Recovery of plutonium from nitric acid waste  

SciTech Connect

Seven candidate materials, each contained in a static-bed column, have been evaluated for removing plutonium from nitric acid waste. Three materials have insufficient capacity for plutonium: TBP (tri-n-butylphosphate) sorbed on Amberlite XAD-4 resin, O phi D(IB)CMPO (octylphenyl-N, N-diisobutylcarbamoylmethylphosphine oxide) sorbed on XAD-4, and Amberlite IRA-938 anion exchange resin. The remaining four materials reduced 10/sup -3/ g/l plutonium in 7.2M HNO/sub 3/ to low 10/sup -5/ g/l for 80 bed volumes (BV). The 10% breakthrough capacities for 3 x 10/sup -2/ g/l plutonium are: TOPO (tri-n-octylphosphine oxide) on XAD-4 - 1800 BV, DHDECMP (dihexyl-N, N-diethylcarbamoylmethylphosphonate) on XAD-4 - 960 BV, Dowex 1 x 4 - 840 BV, and DHDECMP + TBP - 640 BV. Based on these results and generally poor elution of all materials, TOPO on XAD-4 is recommended as the best candidate for recovery of plutonium followed by acid digestion or combustion of the TOPO to recover the concentrated plutonium.

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

1986-12-21

343

Nonreversible immobilization of water-borne plutonium onto self-assembled adlayers of silanized humic materials.  

PubMed

The objective was to study plutonium partitioning between immobile and mobile humic materials at the water-solid interfaces. Immobilization of the humic materials on solid supports was performed in situ using self-adhesive silanized humic derivatives. The presence of the humic adlayers on solid supports was shown to significantly enhance Pu sorption and its retention under both steady state and dynamic conditions. While plutonium may exist in multiple oxidations states plus colloidal forms, the major thrust in this work was to study the behavior of most mobile--the PuO2(+) form in dilute solutions. The values of the plutonium partition coefficients (Kd) between water and humics-coated silica gels after 10 days exposure reached 1.6 × 10(4) L · kg(-1) at pH 7.5 under anaerobic conditions with a total plutonium concentration of 1.2 × 10(-8) M exceeding those for the uncoated SiO2 (6.3 × 10(2) L · kg(-1)). Column tests showed substantial sequestration of water-borne plutonium (up to 73%) on the humics-coated silica gels. Remobilization experiments conducted under batch conditions at different pH values (3.5, 4.5, 7.5) showed that no more than 3% of the sequestered Pu was remobilized from the humics-coated silica gels by treatment with dissolved humic materials at environmentally relevant pH of 7.5. Consequently, silanized humic materialas can be seen as both molecular probes and as potent candidate materials for scavenging mobile Pu from an aqueous phase. PMID:24533599

Shcherbina, Natalia S; Kalmykov, Stepan S; Karpiouk, Leonid A; Ponomarenko, Sergey A; Hatfield, Kirk; Haire, Richard; Perminova, Irina V

2014-02-18

344

Recycle of scrap plutonium-238 oxide fuel to support future radioisotope applications  

SciTech Connect

The Nuclear Materials Technology (NMT) Division of Los Alamos National Laboratory has initiated a development program to recover and purify plutonium-238 oxide from impure feed sources in a glove box environment. A glove box line has been designed and a chemistry flowsheet developed to perform this recovery task at large scale. The initial demonstration effort focused on purification of {sup 238}PuO{sub 2} fuel by HNO{sub 3}/HF dissolution, followed by plutonium(III) oxalate precipitation and calcination to an oxide. Decontamination factors for most impurities of concern in the fuel were very good, producing {sup 238}PuO{sub 2} fuel significantly better in purity than specified by General Purpose Heat Source (GPHS) fuel powder specifications. The results are encouraging for recycle of relatively impure plutonium-238 oxide and scrap residue items into fuel for useful applications. A sufficient quantity of purified {sup 238}PuO{sub 2} fuel was recovered from the process to allow fabrication of a GPHS unit for testing. The high specific activity of plutonium-238 magnifies the consequences and concerns of radioactive waste generation. This work places an emphasis on development of waste minimization technologies to complement the aqueous processing operation. Results from experiments allowing more time for neutralized solutions of plutonium-238 to precipitate resulted in decontamination to about 1 millicurie/L. Combining ultrafiltration treatment with addition of a water-soluble polymer designed to coordinate Pu, allowed solutions to be decontaminated to about 1 microcurie/L. Efforts continue to develop a capability for efficient, safe, cost-effective, and environmentally acceptable methods to recover and purify {sup 238}PuO{sub 2} fuel.

Schulte, L.D.; Espinoza, J.M.; Ramsey, K.B.; Rinehart, G.H.; Silver, G.L.; Purdy, G.M.; Jarvinen, G.D.

1997-11-01

345

Toxicity of Diphenylamine and Some of Its Nitrated and Aminated Derivatives to the Luminescent Bacterium Vibrio fischeri  

Microsoft Academic Search

Aqueous samples containing various nitrated and aminated diphenylamine derivatives were subjected to the luminescent bacterium Vibrio fischeri NRRL-B-11177 to determine their ecotoxicological potential. As the most important toxicological parameter, EC50, the concentration needed to reduce bacterial luminescence by 50%, was calculated. All compounds tested must be classified to the category \\

O. Drzyzga; S. Jannsen; K. H. Blotevogel

1995-01-01

346

Extended testing of a modified 18B plutonium nitrate shipping container  

SciTech Connect

The container damage observed as the result of the high-speed pulldown impact test was more severe than that of either the 185-m free-fall drop of a prototype container onto a semirigid surface or the crush environment produced by a 9-m drop of a 2-tonne block onto a modified container resting on an unyielding surface. In comparison to the extended tests, the 9-m regulatory drop test onto an unyielding surface of the prototype packaging in its most damaging orientation produced the least amount of damage. Very little deformation in the overpack was observed, and there was no influence on the fire resistivity and leaktightness of the containment vessel. The 128 m/s impact test produced a leak in the container. It appears that the 18B packaging, designed to withstand the environments specified in IAEA Safety Series No. 6, can withstand extended environments including longer duration fires and higher velocity impacts on yielding targets. When modified with ring stiffeners, the packaging withstood a dynamic crush test, but did not survive the high speed impact onto an unyielding surface as specified in NUREG 0360.

Yoshimura, H.R.; Pope, R.B.; Leisher, W.B.; Joseph, B.J.; Schulz-Forberg, B.; Hubner, H.W.

1980-01-01

347

Dosimetric and spectrometric neutron measurements around an annular vessel containing a plutonium nitrate fissile solution  

NASA Astrophysics Data System (ADS)

The new ICPR60 recommendations and the consideration of the ALARA principle have led the operators of nuclear facilities to evaluate with a higher care, the doses received by workers. The aim of this paper is to present a recent study concerning mixed field characterisation at a workplace located in a reprocessing laboratory. As a first step, neutron spectrum determination was achieved by two ways: simulation using MCNP code and experimental measurements with Bonner spheres and recoil proton counters. Neutron spectrum allowed the evaluation of dosimetric quantities. Measurements were then performed with different devices routinely used in radioprotection. The authors describe the measurement techniques, present the results obtained, and finally compare and discuss them.

Tournier, B.; Itié, C.; Médioni, R.; Rich, C.; Mussoni, F.; Camus, L.; Pichenot, G.; Crovisier, Ph.; Cutarella, D.; Asselineau, B.; Groetz, J. E.

2002-01-01

348

Phase Transitions of Aqueous Atmospheric Particles  

NASA Astrophysics Data System (ADS)

The physical state of atmospheric particles affect their optical properties, their chemical reactivity, and their atmospheric lifetime. Accordingly, the prediction of particle phase is critical for accurate atmospheric modeling. Atmospheric aqueous particles, due to their small size (submicron), can deeply supercool with respect to freezing (e.g., 40 K) and deeply supersaturate (e.g., S = 35) with respect to relative humidity before crystallization begins via homogeneous nucleation. Atmospheric mineral dusts, incorporated as inclusions within aqueous particles, provide active surfaces to induce crystallization heterogeneously and thus drastically reduce the extent of supercooling (e.g., 20 K) or supersaturation (e.g., S = 5). This talk will present laboratory and theoretical work on several systems, including sulfates, nitrates, and mineral dusts. The results are crucial to providing a quantitative microphysical model that couples the interactions of these particle classes in the atmosphere.

Martin, S. T.

2001-12-01

349

Effect of nitrate on microbial perchlorate reduction  

NASA Astrophysics Data System (ADS)

Over the last decade perchlorate has been recognized as an important emerging water contaminant that poses a significant public health threat. Because of its chemical stability, low ionic charge density, and significant water solubility microbial remediation has been identified as the most feasible method for its in situ attenuation. Our previous studies have demonstrated that dissimilatory perchlorate reducing bacteria (DPRB) capable of the respiratory reduction of perchlorate into innocuous chloride are ubiquitous in soil and sedimentary environments. As part of their metabolism these organisms reduce perchlorate to chlorite which is subsequently dismutated into chloride and molecular oxygen. These initial steps are mediated by the perchlorate reductase and chlorite dismutase enzymes respectively. Previously we found that the activity of these organisms is dependent on the presence of molybdenum and is inhibited by the presence of oxygen and to different extents nitrate. However, to date, there is little understanding of the mechanisms involved in the regulation of perchlorate reduction by oxygen and nitrate. As a continuation of our studies into the factors that control DPRB activity we investigated these regulatory mechanisms in more detail as a model organism, Dechloromonas aromatica strain RCB, transitions from aerobic metabolism through nitrate reduction to perchlorate reduction. In series of growth transition studies where both nitrate and perchlorate were present, preference for nitrate to perchlorate was observed regardless of the nitrate to perchlorate ratio. Even when the organism was pre-grown anaerobically in perchlorate, nitrate was reduced prior to perchlorate. Using non-growth washed cell suspension, perchlorate- grown D. aromatica was capable of reducing both perchlorate and nitrate concomitantly suggesting the preferentially utilization of nitrate was not a result of enzyme functionality. To elucidate the mechanism for preferential utilization of nitrate, transcripts of perchlorate reductase and chlorite dismutase were analyzed to determine possible transcriptional regulation from nitrate. During growth transition studies, increase in the level of transcripts necessary for nitrate reduction and perchlorate reduction was observed concomitantly with decrease in the concentration of nitrate and perchlorate respectively suggesting transcriptional regulation was involved in the preferential utilization of nitrate and that nitrate might be a transcriptional inhibitor of perchlorate reduction. Again, using non-growth washed cell suspensions of perchlorate grown D. aromatica, a decrease of transcript level of the perchlorate reductase but not the chlorite dismutase was observed after incubation with nitrate. In conclusion, from physiological and molecular evidence, nitrate negatively regulates transcription of perchlorate reductase thus inhibiting perchlorate reduction. This result is unexpected as it is in contrast to the accepted dogma that microorganisms regulate their metabolisms to utilize electron acceptors in a sequential manner based on thermodynamic optimization which would imply that perchlorate should be used preferentially to nitrate.

Sun, Y.; Coates, J. D.

2007-12-01

350

Determination of equivalent plutonium content in MOX fuel assemblies  

SciTech Connect

For the design of a core loaded with mixed-oxide (MOX) fuel, it is frequently necessary to determine the plutonium content in an MOX fuel assembly that is equivalent in burnup to a conventional UO{sub 2} fuel assembly. The equivalent plutonium content can be determined experimentally based on the linear reactivity model (LRM) through a number of assembly depletion calculations. In this study, the equivalent total plutonium content in an MOX fuel is correlated with the plutonium isotopic composition, which makes it possible to estimate the equivalent plutonium content without any assembly depletion calculations for a new plutonium with different isotopic compositions.

Yong Bae Kim; Nam Zin Cho [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Democratic People`s Republic of)

1996-12-31

351

Sorptive removal of technetium from heavy metals sludge filtrate containing nitrate ion  

SciTech Connect

We have found that cross-linked polyvinylpyridine (PVP) resin is more efficient than strongly basic anion-exchange resin for removal of technetium in wastes containing high concentrations of nitrate ion. Resin loading by nitrate is greatly reduced, and PVP resins are very stable with respect to chemical and radiological degradation. We have also found that the inexpensive inorganic reagents, elemental iron and ferrous sulfide, are very efficient for the removal of technetium and soluble mercury from aqueous nitrate wastes. The spent reactant and sorbent occupies a much smaller volume (per unit of technetium removed) than does organic resin, and the spent reactant can be immobilized into grout, with a very low leach rate for technetium. 30 refs., 5 figs., 13 tabs.

Bostick, W.D.; Evans-Brown, B.S.

1988-01-01

352

Complexation of Lanthanides with Nitrate at Variable Temperatures: Thermodynamics and Coordination Modes  

SciTech Connect

Complexation of neodymium(III) with nitrate was studied at variable temperatures (25, 40, 55 and 70 C) by spectrophotometry and microcalorimetry. The NdNO{sub 3}{sup 2+} complex is weak and becomes slightly stronger as the temperature is increased. The enthalpy of complexation at 25 C was determined by microcalorimetry to be small and positive, (1.5 {+-} 0.2) kJ {center_dot} mol{sup -1}, in good agreement with the trend of the stability constant at variable temperatures. Luminescence emission spectra and lifetime of Eu(III) in nitrate solutions suggest that inner-sphere and bidentate complexes form between trivalent lanthanides (Nd{sup 3+} and Eu{sup 3+}) and nitrate in aqueous solutions. Specific Ion Interaction approach (SIT) was used to obtain the stability constants of NdNO{sub 3}{sup 2+} at infinite dilution and variable temperatures.

Rao, Linfeng; Tian, Guoxin

2008-12-10

353

Adsorption of phosphate and nitrate anions on ammonium-functionalized MCM-48: effects of experimental conditions.  

PubMed

In this study, ammonium-functionalized MCM-48 (Mobil Composite Material No. 48) was used as an adsorbent to remove nitrate (NO(-)(3)) and monobasic phosphate (H(2)PO(-)(4)) anions from aqueous solutions. The effects of operating conditions such as temperature, adsorbent loading, initial anion concentration, pH, and the presence of competitive ions on the adsorption performances were examined. Results showed that adsorption capacity decreased with increasing temperature. The adsorption capacity increased with adsorbent loading and initial anion concentration. The removal of nitrate was maximum at pH<8, while phosphate removal was maximized at pH 5. The adsorption was almost unaffected by the presence of competitive ions in the case of phosphate anions. However, their presence adversely affected nitrate adsorption. Desorption of both anions was rapidly achieved within 10 min using NaOH at 0.01 M. Regeneration tests showed that the adsorbent retained its capacity after 5 adsorption-desorption cycles. PMID:17451734

Saad, Rabih; Belkacemi, Khaled; Hamoudi, Safia

2007-07-15

354

Photoemission Spectroscopy of Delta- Plutonium: Experimental Review  

NASA Astrophysics Data System (ADS)

The electronic structure of Plutonium, particularly delta- Plutonium, remains ill defined and without direct experimental verification. Recently, we have embarked upon a program of study of alpha- and delta- Plutonium, using synchrotron radiation from the Advanced Light Source in Berkeley, CA, USA [1]. This work is set within the context of Plutonium Aging [2] and the complexities of Plutonium Science [3]. The resonant photoemission of delta-plutonium is in partial agreement with an atomic, localized model of resonant photoemission, which would be consistent with a correlated electronic structure. The results of our synchrotron- based studies will be compared with those of recent laboratory- based works [4,5,6]. The talk will conclude with a brief discussion of our plans for the future, such as the performance of spin-resolving and dichroic photoemission measurements of Plutonium [7] and the development of single crystal ultrathin films of Plutonium. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. 1. J. Terry, R.K. Schulze, J.D. Farr, T. Zocco, K. Heinzelman, E. Rotenberg, D.K. Shuh, G. van der Laan, D.A. Arena, and J.G. Tobin, “5f Resonant Photoemission from Plutonium”, UCRL-JC-140782, Surf. Sci. Lett., accepted October 2001. 2. B.D. Wirth, A.J. Schwartz, M.J. Fluss, M.J. Caturla, M.A. Wall, and W.G. Wolfer, MRS Bulletin 26, 679 (2001). 3. S.S. Hecker, MRS Bulletin 26, 667 (2001). 4. T. Gouder, L. Havela, F. Wastin, and J. Rebizant, Europhys. Lett. 55, 705 (2001); MRS Bulletin 26, 684 (2001); Phys. Rev. Lett. 84, 3378 (2000). 5. A.J. Arko, J.J. Joyce, L. Morales, J. Wills, J. Lashley, F. Wastin, and J. Rebizant, Phys. Rev. B 62, 1773 (2000). 6. L.E. Cox, O. Eriksson, and B.R. Cooper, Phys. Rev. B 46, 13571 (1992). 7. J. Tobin, D.A. Arena, B. Chung, P. Roussel, J. Terry, R.K. Schulze, J.D. Farr, T. Zocco, K. Heinzelman, E. Rotenberg, and D.K. Shuh, “Photoelectron Spectroscopy of Plutonium at the Advanced Light Source”, UCRL-JC-145703, J. Nucl. Sci. Tech./ Proc. of Actinides 2001, submitted November 2001.

Tobin, J. G.

2002-03-01

355

Thermal decomposition of energetic materials 32. on the instantaneous molecular nature of aqueous liquid gun propellants at high temperature and pressure before thermal decomposition  

Microsoft Academic Search

By analogy with recent studies on the molecular behavior of concentrated aqueous nitrate salt solutions at high pressure and temperature, hydroxylammonium nitrate-based liquid propellants would be expected to contain relatively covalent, contact ion pairs the instant before chemical decomposition ensues at high temperature and pressure. This may accentuate the first step of the decomposition process which appears to be proton

T. B. Brill; P. D. Spohn; J. T. Cronin

1990-01-01

356

Biodegradability of 2-ethylhexyl nitrate (2-EHN), a cetane improver of diesel oil  

Microsoft Academic Search

The 2-ethyhexyl nitrate (2-EHN) is currently added to diesel oil to improve ignition and boost cetane number. The biodegradability\\u000a of this widely used chemical needed to be assessed in order to evaluate the environmental impact in case of accidental release.\\u000a In aerobic liquid cultures, biodegradation of 2-EHN was assessed in biphasic liquid cultures using an inert non-aqueous phase\\u000a liquid such

Floriane Solano-Serena; Elodie Nicolau; Grégory Favreau; Yves Jouanneau; Rémy Marchal

2009-01-01

357

Extraction of REE(III) Nitrates with Polymer-Supported Tributyl Phosphate  

Microsoft Academic Search

Extraction of La, Ce, Pr, Nd, Sm, and Y(III) nitrates with polymer-supported TBP in the presence of 1-5 M NaNO3 in the aqueous phase is studied. The extraction isotherms are described taking into account formation of [Ln(NO3)3(TBP)j](o) (j = 3, 4) in the extractant phase. The extraction constants corrected for the TBP concentration in the extractant phase are considerably higher

A. K. Pyartman; V. A. Keskinov; M. A. Mikhailenko; N. V. Nikitin; V. V. Lishchuk

2004-01-01

358

Nitrate ion detection in aerosols using morphology-dependent stimulated Raman scattering  

SciTech Connect

A nitrate ion concentration of 5{times}10{sup {minus}5}M has been detected in {approximately}180 {mu}m diam aqueous aerosols using morphology-dependent stimulated Raman scattering (MDSRS). This low concentration was detected by allowing the droplet size to be tuned during an experiment. Comparison of the experimental results with the MDSRS gain equation shows that it may be possible to detect concentrations a factor of ten lower. {copyright} {ital 1999 American Institute of Physics.}

Aker, P.M.; Zhang, J.; Nichols, W. [Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)] [Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)

1999-01-01

359

Formation of nanostructured hydrogels in L-cysteine and silver nitrate solutions  

Microsoft Academic Search

Transmission electron microscopy is utilized to study the gels formed from aqueous solutions of L-cysteine and silver nitrate\\u000a on a nanolevel structure in the presence of various anions. It is established that the anion’s charge and geometrical size\\u000a have an existential effect on the structure and mechanical properties of the spatial gel-network.

P. M. Pakhomov; S. S. Abramchuk; S. D. Khizhnyak; M. M. Ovchinnikov; V. M. Spiridonova

2010-01-01

360

Formation of nanoscale supramolecular aggregates in cysteine-silver nitrate solutions  

Microsoft Academic Search

The gelling process in an aqueous solution of cysteine-silver nitrate was studied within the ZINDO\\/1 quantum chemistry method.\\u000a As shown previously, silver mercaptide (SM) molecules are formed in the first self-assembly stage in such systems, based on\\u000a which, supramolecular aggregates (SA) can be formed. The SA stability was studied as a function of the number of SM molecules\\u000a at their

P. V. Komarov; I. P. Sannikov; S. D. Khizhnyak; M. M. Ovchinnikov; P. M. Pakhomov

2008-01-01

361

Growth, Structural, Spectral and Optical Studies of Glycine Sodium Nitrate Doped Potassium Dihydrogen Phosphate Single Crystals  

NASA Astrophysics Data System (ADS)

Single crystals of Pure and Glycine sodium nitrate (GSN) doped Potassium dihydrogen Phosphate (KDP) were grown from aqueous solution by slow evaporation technique. The cell parameters of the grown pure and GSN doped KDP crystals were estimated by Single X-ray diffraction studies. The functional groups present in the grown crystals were ascertained using FTIR spectral analysis. The UV-Vis-NIR transmission spectra reveals that the semiorganic dopant has increased the optical transparency of the KDP crystals.

Loretta, Fernando; Rani, T. Josephine; Perumal, S.; Ramalingom, S.

2011-10-01

362

Winter Wheat and Maize Response to Urea Ammonium Nitrate and a New Urea Formaldehyde Polymer Fertilizer  

Microsoft Academic Search

Slow release N fertilizers have potential to improve yield and nitrogen use efficiency (NUE) in winter wheat (Triticum aestivum L.) and maize (Zea mays L.). A slow release urea formaldehyde polymer (UFP) was compared with aqueous urea ammonium nitrate (UAN) ((NH2)2CO, NH4NO3) during a 2-yr field experiment in North Carolina. Crops were grown on Candor (sandy, siliceous, thermic Grossarenic Kandiudults),

Sheri Cahill; Deanna Osmond; Carl Crozier; Daniel Israel; Randy Weisz

2007-01-01

363

Plutonium(IV) cluster with a hexanuclear [Pu6(OH)4O4]12+ core.  

PubMed

A mixed hydroxo/oxo plutonium(IV) carboxylate resulting from the hydrolysis and condensation of Pu(IV) in an acidic aqueous solution has been isolated. The structure of Li6[Pu6(OH)4O4(H2O)6(HGly)12]Cl18·10.5H2O (1) consists of a cationic [Pu6(OH)4O4](12+) core that is decorated by glycine ligands. The synthesis, structure, and characterization of the hexanuclear unit, which represents the first example of a Pu(IV) polynuclear complex containing both hydroxo- and oxo-bridging ligands, are described herein. PMID:23713867

Knope, Karah E; Soderholm, L

2013-06-17

364

Plutonium dioxide dissolution in glass  

SciTech Connect

In the aftermath of the Cold War, the U.S. Department of Energy`s (DOE) Office of Fissile Materials Disposition (OFMD) is charged with providing technical support for evaluation of disposition options for excess fissile materials manufactured for the nation`s defense. One option being considered for the disposition of excess plutonium (Pu) is immobilization by vitrification. The vitrification option entails immobilizing Pu in a host glass and waste package that are criticality-safe (immune to nuclear criticality), proliferation-resistant, and environmentally acceptable for long-term storage or disposal. To prove the technical and economic feasibility of candidate vitrification options it is necessary to demonstrate that PuO{sub 2} feedstock can be dissolved in glass in sufficient quantity. The OFMD immobilization program has set a Pu solubility goal of 10 wt% in glass. The life cycle cost of the vitrification options are strongly influenced by the rate at which PUO{sub 2} dissolves in glass. The total number of process lines needed for vitrification of 50 t of Pu in 10 years is directly dependent upon the time required for Pu dissolution in glass. The objective of this joint Pacific Northwest National Laboratory (PNNL) - Savannah River Technology Center (SRTC) study was to demonstrate a high Pu solubility in glass and to identify on a rough scale the time required for Pu dissolution in the glass. This study was conducted using a lanthanide borosilicate (LaBS) glass composition designed at the SRTC for the vitrification of actinides.

Vienna, J.D.; Alexander, D.L.; Li, Hong [and others

1996-09-01

365

Anharmonic effects in ammonium nitrate and hydroxylammonium nitrate clusters.  

PubMed

The covalent and ionic clusters of ammonium nitrate and hydroxyl ammonium nitrate are characterized using density functional theory and second-order vibrational perturbation theory. The most stable structures are covalent acid-base pairs for the monomers and ionic acid-base pairs for the dimers. The hydrogen-bonding distances are greater in the ionic dimers than in the covalent monomers, and the stretching frequencies are significantly different in the covalent and ionic clusters. The anharmonicity of the potential energy surfaces is found to influence the geometries, frequencies, and nuclear magnetic shielding constants for these systems. The inclusion of anharmonic effects significantly decreases many of the calculated vibrational frequencies in these clusters and improves the agreement of the calculated frequencies with the experimental data available for the isolated neutral species. The calculations of nuclear magnetic shielding constants for all nuclei in these clusters illustrate that quantitatively accurate predictions of nuclear magnetic shieldings for comparison to experimental data require the inclusion of anharmonic effects. These calculations of geometries, frequencies, and shielding constants provide insight into the significance of anharmonic effects in ionic materials and provide data that will be useful for the parametrization of molecular mechanical force fields for ionic liquids. Anharmonic effects will be particularly important for the study of proton transfer reactions in ionic materials. PMID:17474693

Kumarasiri, Malika; Swalina, Chet; Hammes-Schiffer, Sharon

2007-05-10

366

Physiological aspects of ammonium and nitrate fertilization  

Microsoft Academic Search

Various physiological effects of ammonium, nitrate and mixed ammonium?nitrate nutrition of plants have been studied in this laboratory during the last years. Some of the characteristic distinctions observed between plants growing on these nitrogen sources are described and discussed. Biomass production of ammonium?grown plants increased with K concentration in the nutrient medium between 0.1 to 3 mM , while nitrate?fed

S. H. Lips; E. O. Leidi; M. Silberbush; M. I. M. Soares; O. E. M. Lewis

1990-01-01

367

Plutonium Recovery at the Los Alamos Scientific Laboratory.  

National Technical Information Service (NTIS)

Research programs have led to the adoption of procedures for all phases of plutonium recovery and purification. This report discusses some of the many procedures required to recover and purify the plutonium contained in the residues generated by LASL rese...

E. L. Christensen

1980-01-01

368

Crystalline plutonium hosts derived from high-level waste formulations.  

National Technical Information Service (NTIS)

The Department of Energy has selected immobilization for disposal in a repository as one approach for disposing of excess plutonium (1). Materials for immobilizing weapons-grade plutonium for repository disposal must meet the 'spent fuel standard' by prov...

T. P. O'Holleran

1998-01-01

369

Recent improvements in plutonium gamma-ray analysis using MGA.  

National Technical Information Service (NTIS)

MGA is a gamma-ray spectrum analysis program for determining relative plutonium isotopic abundances. It can determine plutonium isotopic abundances better than 1% using a high-resolution, low-energy, planar germanium detector and measurement times ten min...

W. D. Ruhter R. Gunnink

1992-01-01

370

Density and Tensile Properties Changed by Aging Plutonium.  

National Technical Information Service (NTIS)

We present volume, density, and tensile property change observed from both naturally and accelerated aged plutonium alloys. Accelerated alloys are plutonium alloys with a fraction of Pu-238 to accelerate the aging process by approximately 18 times the rat...

2005-01-01

371

69. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING SOUTHWEST THROUGH ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

69. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING SOUTHWEST THROUGH DOOR-WAY INTO PLUTONIUM STORAGE AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

372

71. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING NORTHEAST INTO ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

71. INTERIOR, BUILDING 272 (PLUTONIUM STORAGE BUILDING) LOOKING NORTHEAST INTO PLUTONIUM STORAGE ROOM SHOWING CUBICLES FOR STORAGE. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

373

Preserving Plutonium-244 as a National Asset  

SciTech Connect

Plutonium-244 (244 Pu) is an extremely rare and long-lived isotope of plutonium with a half-life of 80 million years. Measureable amounts of 244 Pu are found in neither reactor-grade nor weapons-grade plutonium. Production of this isotope requires a very high thermal flux to permit the two successive neutron captures that convert 242 Pu to 243 Pu to 244 Pu, particularly given the short (about 5 hour) half-life of 243 Pu. Such conditions simply do not exist in plutonium production processes. Therefore, 244 Pu is ideal for precise radiochemical analyses measuring plutonium material properties and isotopic concentrations in items containing plutonium. Isotope dilution mass spectrometry is about ten times more sensitive when using 244 Pu rather than 242 Pu for determining plutonium isotopic content. The isotope can also be irradiated in small quantities to produce superheavy elements. The majority of the existing global inventory of 244 Pu is contained in the outer housing of Mark-18A targets at the Savannah River Site (SRS). The total inventory is about 20 grams of 244 Pu in about 400 grams of plutonium distributed among the 65 targets. Currently, there are no specific plans to preserve these targets. Although the cost of separating and preserving this material would be considerable, it is trivial in comparison to new production costs. For all practical purposes, the material is irreplaceable, because new production would cost billions of dollars and require a series of irradiation and chemical separation cycles spanning up to 50 years. This paper will discuss a set of options for overcoming the significant challenges to preserve the 244 Pu as a National Asset: (1) the need to relocate the material from SRS in a timely manner, (2) the need to reduce the volume of material to the extent possible for storage, and (3) the need to establish an operational capability to enrich the 244 Pu in significant quantities. This paper suggests that if all the Mark-18A plutonium is separated, it would occupy a small volume and would be inexpensive to store while an enrichment capability is developed. Very small quantities could be enriched in existing mass separators to support critical needs.

Patton, Bradley D [ORNL; Alexander, Charles W [ORNL; Benker, Dennis [ORNL; Collins, Emory D [ORNL; Romano, Catherine E [ORNL; Wham, Robert M [ORNL

2011-01-01

374

Trend Analyses of Nitrate in Danish Groundwater  

NASA Astrophysics Data System (ADS)

This presentation assesses the long-term development in the oxic groundwater nitrate concentration and nitrogen (N) loss due to intensive farming in Denmark. Firstly, up to 20-year time-series from the national groundwater monitoring network enable a statistically systematic analysis of distribution, trends and trend reversals in the groundwater nitrate concentration. Secondly, knowledge about the N surplus in Danish agriculture since 1950 is used as an indicator of the potential loss of N. Thirdly, groundwater recharge CFC (Chlorofluorocarbon) age determination allows linking of the first two dataset. The development in the nitrate concentration of oxic groundwater clearly mirrors the development in the national agricultural N surplus, and a corresponding trend reversal is found in groundwater. Regulation and technical improvements in the intensive farming in Denmark have succeeded in decreasing the N surplus by 40% since the mid 1980s while at the same time maintaining crop yields and increasing the animal production of especially pigs. Trend analyses prove that the youngest (0-15 years old) oxic groundwater shows more pronounced significant downward nitrate trends (44%) than the oldest (25-50 years old) oxic groundwater (9%). This amounts to clear evidence of the effect of reduced nitrate leaching on groundwater nitrate concentrations in Denmark. Are the Danish groundwater monitoring strategy obtimal for detection of nitrate trends? Will the nitrate concentrations in Danish groundwater continue to decrease or are the Danish nitrate concentration levels now appropriate according to the Water Framework Directive?

Hansen, B.; Thorling, L.; Dalgaard, T.; Erlandsen, M.

2012-04-01

375

Photochemistry of Nitrate Adsorbed on Mineral Dust  

NASA Astrophysics Data System (ADS)

Mineral dust particles in the atmosphere are often associated with adsorbed nitrate from heterogeneous reactions with nitrogen oxides including HNO3 and NO2. Although nitrate ion is a well-studied chromophore in natural waters, the photochemistry of adsorbed nitrate on mineral dust particles is yet to be fully explored. In this study, wavelength dependence of the photochemistry of adsorbed nitrate on different model components of mineral dust aerosol has been investigated using transmission FTIR spectroscopy. Al2O3, TiO2 and NaY zeolite were used as model systems to represent non-photoactive oxides, photoactive semiconductor oxides and porous materials respectively, present in mineral dust aerosol. In this study, adsorbed nitrate is irradiated with 254 nm, 310 nm and 350 nm narrow band light. In the irradiation with narrow band light, NO2 is the only detectable gas-phase product formed from nitrate adsorbed on Al2O3 and TiO2. The NO2 yield is highest at 310 nm for both Al2O3 and TiO2. Unlike Al2O3 and TiO2, in zeolite, adsorbed nitrate photolysis to nitrite is observed only at 310 nm during narrow band irradiation. Moreover gas phase products were not detected during nitrate photolysis in zeolite at all three wavelengths. The significance of these differences as related to nitrate photochemistry on different mineral dust components will be highlighted.

Gankanda, A.; Grassian, V. H.

2013-12-01

376

Plutonium and uranium adsorption on monosodium titanate  

SciTech Connect

Adsorption of Pu and U onto monosodium titanate (MST) in alkaline salt solution was measured. Changes in MST particle size distribution do not significantly affect the loadings of actinides. Max loading of plutonium-239 is 0.68 wt% at 0.79 mg/L Pu, below the infinitely safe value of 0.80 wt%. Max loading of uranium-235 onto MST is 1.4 wt% at a concentration of 20.3 {plus_minus} 2.0 mg/L U, slightly higher than the calculated infinitely safe limit of 1.2 wt%. Experimental data indicated there is competition between plutonium and uranium for sites on the MST, and that the loading will favor the higher concentration species. Since the solubility of uranium is 10--100 times higher than of plutonium, uranium will be loaded to its maximum limit, but plutonium will be below its maximum limit. To ensure that the concentration of fissile materials cannot exceed nuclear safety limits, it is recommended that plutonium and uranium solubility tests be conducted with solutions which bound the compositions of waste which will be treated in ITP process.

Hobbs, D.T.; Walker, D.D.

1992-08-13

377

Plutonium and uranium adsorption on monosodium titanate  

SciTech Connect

Adsorption of Pu and U onto monosodium titanate (MST) in alkaline salt solution was measured. Changes in MST particle size distribution do not significantly affect the loadings of actinides. Max loading of plutonium-239 is 0.68 wt% at 0.79 mg/L Pu, below the infinitely safe value of 0.80 wt%. Max loading of uranium-235 onto MST is 1.4 wt% at a concentration of 20.3 [plus minus] 2.0 mg/L U, slightly higher than the calculated infinitely safe limit of 1.2 wt%. Experimental data indicated there is competition between plutonium and uranium for sites on the MST, and that the loading will favor the higher concentration species. Since the solubility of uranium is 10--100 times higher than of plutonium, uranium will be loaded to its maximum limit, but plutonium will be below its maximum limit. To ensure that the concentration of fissile materials cannot exceed nuclear safety limits, it is recommended that plutonium and uranium solubility tests be conducted with solutions which bound the compositions of waste which will be treated in ITP process.

Hobbs, D.T.; Walker, D.D.

1992-08-13

378

Long-term plutonium storage: Design concepts  

SciTech Connect

An important part of the Department of Energy (DOE) Weapons Complex Reconfiguration (WCR) Program is the development of facilities for long-term storage of plutonium. The WCR design goals are to provide storage for metals, oxides, pits, and fuel-grade plutonium, including material being held as part of the Strategic Reserve and excess material. Major activities associated with plutonium storage are sorting the plutonium inventory, material handling and storage support, shipping and receiving, and surveillance of material in storage for both safety evaluations and safeguards and security. A variety of methods for plutonium storage have been used, both within the DOE weapons complex and by external organizations. This paper discusses the advantages and disadvantages of proposed storage concepts based upon functional criteria. The concepts discussed include floor wells, vertical and horizontal sleeves, warehouse storage on vertical racks, and modular storage units. Issues/factors considered in determining a preferred design include operational efficiency, maintenance and repair, environmental impact, radiation and criticality safety, safeguards and security, heat removal, waste minimization, international inspection requirements, and construction and operational costs.

Wilkey, D.D.; Wood, W.T. [Los Alamos National Lab., NM (United States); Guenther, C.D. [Fluor Daniel, Inc., Irvine, CA (United States)

1994-08-01

379

Dispersion of plutonium from contaminated pond sediments  

USGS Publications Warehouse

Sediment-water distributions of plutonium as a function of pH and contact time are investigated in a holding pond at the Rocky Flats plant of the Department of Energy. Although plutonium has been shown to sorb from natural waters onto sediments, the results of this study indicate that under the proper conditions it can be redispersed at pH 9 and above. Concentrations greater than 900 pCi Pu/L result after 34 h contact at pH 11 or 12 and the distribution coefficient, defined as the ratio of concentration in the sediment to that in the liquid, decreases from 1.1 ?? 105 at pH 7 to 1.2 ?? 103 at pH 11. The plutonium is probably dispersed as discrete colloids or as hydrolytic species adsorbed onto colloidal sediment particles whose average size decreases with increasing pH above pH 9. About 5% of the total plutonium is dispersed at pH 12, and the dispersion seems to readsorb on the sediment with time. Consequently, migration of plutonium from the pond should be slow, and it would be difficult to remove this element completely from pond sediment by leaching with high pH solutions. ?? 1978 American Chemical Society.

Rees, T. F.; Cleveland, J. M.; Carl, Gottschall, W.

1978-01-01

380

The negative effect of nitrate on gametogenesis is independent of nitrate assimilation in Chlamydomonas reinhardtii  

Microsoft Academic Search

.  ?The effect of nitrate on gamete differentiation as well as on the expression of genes involved in gametogenesis, nitrogen\\u000a scavenging, and nitrate assimilation has been analyzed in wild-type and mutant strains of Chlamydomonas reinhardtii. Nitrate prevented gamete formation from wild-type strains and caused a strong reduction in the number of zygotes recovered\\u000a in genetic crosses between nitrate-assimilation-deficient mutants, thus suggesting

Mercedes Pozuelo; Faustino Merchán; María Isabel Macías; Christoph F. Beck; Aurora Galván; Emilio Fernández

2000-01-01

381

Processing of Non-PFP Plutonium Oxide in Hanford Plants  

Microsoft Academic Search

Processing of non-irradiated plutonium oxide, PuO2, scrap for recovery of plutonium values occurred routinely at Hanfords Plutonium Finishing Plant (PFP) in glovebox line operations. Plutonium oxide is difficult to dissolve, particularly if it has been high-fired; i.e., calcined to temperatures above about 400°C and much of it was. Dissolution of the PuO2 in the scrap typically was performed in PFPs

Susan A. Jones; Calvin H. Delegard

2011-01-01

382

Plutonium metal and alloy preparation by molten chloride reduction  

SciTech Connect

Satisfactory reduction of molten plutonium trichloride (pure and in combination with 20 wt % sodium chloride) by calcium, lanthanum, and cerium has been demonstrated on the 10-g scale. The yields were satisfactory for this scale of operation, and it is indicated that these reductions may be useful for large-scale operations. Significant separations of plutonium from rare earth impurities was demonstrated for lanthanum and cerium reductions. Preparation of plutonium-cerium and plutonium-cerium-cobalt alloys during reduction was also demonstrated.

Reavis, J.G.

1984-01-01

383

The effect of aqueous solution in Raman spectroscopy  

Microsoft Academic Search

In Raman detection, the most popular solution for the samples is tri-distilled water. But the effect of aqueous solution is barely studied in Raman spectroscopy. In fact Raman spectroscopy of solid-state and liquid-state are obvious different. In addition, FWHM of Raman spectral peaks also change evidently. In this paper, several samples were selected for the experiment; including sodium nitrate, sodium

Jian Kang; Xiaojuan Yuan; Xiao Dong; Huaimin Gu

2009-01-01

384

Fused salt processing of impure plutonium dioxide to high-purity plutonium metal  

SciTech Connect

A process for converting impure plutonium dioxide (approx. 96% pure) to high-purity plutonium metal (>99.9%) was developed. The process consists of reducing the oxide to an impure plutonium metal intermediate with calcium metal in molten calcium chloride. The impure intermediate metal is cast into an anode and electrorefined to produce high-purity plutonium metal. The oxide reduction step is being done now on a 0.6-kg scale with the resulting yield being >99.5%. The electrorefining is being done on a 4.0-kg scale with the resulting yield being 80 to 85%. The purity of the product, which averages 99.98%, is essentially insensitive to the purity of the feed metal. The yield, however, is directly dependent on the chemical composition of the feed. To date, approximately 250 kg of impure oxide has been converted to pure metal by this processing sequence. The availability of impure plutonium dioxide, together with the need for pure plutonium metal, makes this sequence a valuable plutonium processing tool.

Mullins, L.J.; Christensen, D.C.; Babcock, B.R.

1982-01-01

385

REDUCTION OF NITRATE THROUGH THE USE OF NITRATE REDUCTASE FOR THE SMARTCHEM AUTOANALYZER  

EPA Science Inventory

The standard method for the determination of nitrate in drinking water, USEPA Method 353.2 ¿Determination of Nitrate-Nitrite by Automated Colorimetry,¿ employs cadmium as the reductant for the conversion of nitrate to nitrite. The nitrite is then analyzed colorimetrically by way ...

386

Rapid colorimetric determination of nitrate in plant tissue by nitration of salicylic acid  

Microsoft Academic Search

An analysis is described for the rapid determination of nitrate?N in plant extracts. The complex formed by nitration of salicylic acid under highly acidic conditions absorbs maximally at 410 nm in basic (pH>12) solutions. Absorbance of the chromophore is directly proportional to the amount of nitrate?N present. Ammonium, nitrite, and chloride ions do not interfere.

D. A. Cataldo; M. Maroon; L. E. Schrader; V. L. Youngs

1975-01-01

387

Challenges with nitrate therapy and nitrate tolerance: prevalence, prevention, and clinical relevance.  

PubMed

Nitrate therapy has been an effective treatment for ischemic heart disease for over 100 years. The anti-ischemic and exercise-promoting benefits of sublingually administered nitrates are well established. Nitroglycerin is indicated for the relief of an established attack of angina and for prophylactic use, but its effects are short lived. In an effort to increase the duration of beneficial effects, long-acting orally administered and topical applications of nitrates have been developed; however, following their continued or frequent daily use, patients soon develop tolerance to these long-acting nitrate preparations. Once tolerance develops, patients begin losing the protective effects of the long-acting nitrate therapy. By providing a nitrate-free interval, or declining nitrate levels at night, one can overcome or reduce the development of tolerance, but cannot provide 24-h anti-anginal and anti-ischemic protection. In addition, patients may be vulnerable to occurrence of rebound angina and myocardial ischemia during periods of absent nitrate levels at night and early hours of the morning, and worsening of exercise capacity prior to the morning dose of the medication. This has been a concern with nitroglycerin patches but not with oral formulations of isosorbide-5 mononitrates, and has not been adequately studied with isosorbide dinitrate. This paper describes problems associated with nitrate tolerance, reviews mechanisms by which nitrate tolerance and loss of efficacy develop, and presents strategies to avoid nitrate tolerance and maintain efficacy when using long-acting nitrate formulations. PMID:24664980

Thadani, Udho

2014-08-01

388

A Pulse Radiolysis Investigation of the Reactions of Tributyl Phosphate with the Radical Products of Aqueous Nitric Acid Irradiation  

Microsoft Academic Search

Tributyl phosphate (TBP) is the most common organic compound used in liquid-liquid separations for the recovery of uranium, neptunium, and plutonium from acidic nuclear fuel dissolutions. The goal of these processes is to extract the actinides while leaving fission products in the acidic, aqueous, phase. However, the radiolytic degradation of TBP has been shown to reduce the separation factors for

Bruce J. Mincher; Stephen R. Mezyk; Leigh R. Martin

2008-01-01

389

Nitrite and Nitrate in Cancer  

Microsoft Academic Search

\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a \\u000a Studies in animal models established the feasibility of sodium nitrite contributing to gastric carcinogenesis primarily via\\u000a conversion to nitrosamines.\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a \\u000a Most animal studies did not corroborate this assumption.\\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a \\u000a Exposure of humans to nitrates is primarily from vegetables.\\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a \\u000a Since a fraction of nitrate is reduced to nitrite by oral bacteria, the largest source of nitrite exposure is also

David M. Klurfeld

390

Molecular Structure of Urea nitrate  

NSDL National Science Digital Library

Urea nitrate is a plastic explosive used for the charge on a nuclear weapon or as a component of a non-nuclear high explosive. It can also be used as a catalyst in Diels-Alder reactions of aromatic amines. It is favored by amateur terrorists because it is fairly easily derived from urea fertilizers or made by combining nitric and uric acids. Nitric acid can be found as waste from several industrial processes, while urea can be found as biological waste from most animals (in the form of urine). Thus, it provides similar explosive power, but lower cost, as TNT. Additionally, it is quite stable, with low friction and shock sensitivity, making it somewhat stable to work with, but also causing it to require an additional more unstable chemical detonator, called a booster, for use as a high explosive. However, in use as an industrial explosive, urea nitrate is used as a sensitizer to a less reactive fuel. It was the main component of the explosive used in the 1993 bombing of the World Trade Center.

2002-09-23

391

Response to suspected or known intakes of plutonium (Draft)  

SciTech Connect

The techniques used at Hanford for routine surveillance, incident detection and prompt assessment of a plutonium intake are reviewed. The techniques described are based on experience from some 80,000 man-years of plutonium work at Hanford which included a variety of manufacturing and R and D programs and involved several isotopes and chemical forms of plutonium.

Heid, K.R.

1983-04-01

392

15. VIEW OF THE SAFE GEOMETRY PLUTONIUM METAL STORAGE PALLETS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. VIEW OF THE SAFE GEOMETRY PLUTONIUM METAL STORAGE PALLETS FROM THE INSIDE OF AN INPUT-OUTPUT STATION. INDIVIDUAL CONTAINERS OF PLUTONIUM ARE STORED IN THE WATER-FILLED, DOUBLE-WALLED STAINLESS STEEL TUBES THAT ARE WELDED ONTO THE PALLETS. (12/3/88) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

393

Application of Fusion Neutron Source for Denaturing of Plutonium  

Microsoft Academic Search

Potential of DT fusion neutron source to enhance proliferation resistance properties of plutonium by means of its isotopic denaturing is addressed. The approach is exemplified by denaturing of pure Pu and plutonium of typical LWR spent fuel through transmutation of neptunium. The essential feature of a fusion driven system proposed in the study is a zero mass balance of plutonium:

Alan TAKIBAYEV; Masaki SAITO; Hiroshi SAGARA

2007-01-01

394

US and Russia face urgent decisions on weapons plutonium  

Microsoft Academic Search

Surplus plutonium poses a clear and present danger to national and international security,'' warns a National Academy of Sciences (NAS) study released in January, titled The Management and Disposition of Excess Weapons Plutonium.'' Over the past few years, many different methods of disposing of plutonium have been proposed. They range from shooting it into the Sun with missiles, to deep-seabed

Hileman

1994-01-01

395

10 CFR 71.88 - Air transport of plutonium.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy...Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions...applicable, the licensee shall assure that plutonium in any form, whether for...

2009-01-01

396

10 CFR 71.88 - Air transport of plutonium.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy...Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions...applicable, the licensee shall assure that plutonium in any form, whether for...

2010-01-01

397

VIEW OF THE INTERIOR OF THE PLUTONIUM LABORATORY IN BUILDING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF THE INTERIOR OF THE PLUTONIUM LABORATORY IN BUILDING 559. THE LABORATORY WAS USED TO ANALYZE THE PURITY OF PLUTONIUM. PLUTONIUM SAMPLES WERE CONTAINED WITHIN GLOVE BOXES - Rocky Flats Plant, Chemical Analytical Laboratory, North-central section of Plant, Golden, Jefferson County, CO

398

Plutonium Isotopic Composition by Gamma-Ray Spectroscopy  

Microsoft Academic Search

of plutonium isotopic composition is usually required to interpret the results of neutron coincidence or calorimetry measurements. Several methods have been developed for determining plutonium isotopic composition by gamma-ray spectroscopy;, some of the early approaches are described in Refs. 1 through 5. An American Society for Testing and Materials standard test method has been written for plutonium isotopic analysis using

Z E Sampson

399

Disposition of plutonium in deep boreholes  

SciTech Connect

Substantial inventories of excess plutonium are expected to result from dismantlement of U.S. and Russian nuclear weapons. Disposition of this material should be a high priority in both countries. A variety of disposition options are under consideration. One option is to place the plutonium either directly or in an immobilized form at the bottom of a deep borehole that is then sealed. Deep-borehole disposition involves placing plutonium several kilometers deep into old, stable, rock formations that have negligible free water present. Containment assurance is based on the presence of ancient groundwater indicating lack of migration and communication with the biosphere. Recovery would be extremely difficult (costly) and impossible to accomplish clandestinely.

Halsey, W.G.; Jardine, L.J.; Walter, C.E.

1995-05-01

400

Characterization of Delta Phase Plutonium Metal  

SciTech Connect

The FB-Line facility has developed the capability to recast plutonium metal using an M-18 reduction furnace with a new casting chamber. Plutonium metal is recast by charging a standard FB-Line magnesia crucible and placing the charge in the casting chamber. The loaded casting chamber is raised into the M-18 reduction furnace and sealed against the furnace head using a copper gasket following the same procedure used for a bomb reduction run. The interior volume of the chamber is evacuated and backfilled with argon gas. The M-18 motor-generator set is used to heat the surface of the casting chamber to nominally 750 Degrees C. Within about 2 hr, the plutonium metal reaches its melting temperature of approximately 640 Degrees C.

Rudisill, T.S.

2000-09-21

401

The United States Plutonium Balance, 1944 - 2009  

SciTech Connect

This report updates the report -Plutonium: The first 50 years- which was released by the U.S.Department of Energy (DOE) in 1996. The topic of both reports is plutonium, sometimes referred to as Pu-239, which is capable of sustaining a nuclear chain reaction and is used in nuclear weapons and for nuclear power production. This report updates 1994 data through 2009. The four most significant changes since 1994 include: (a) the completion of cleanup activities at the Rocky Flats Plant in 2005; (b) material consolidation and disposition activities, especially shipments from Hanford to the Savannah River Site; (c) the 2007 declaration of an additional 9.0 MT of weapons grade plutonium to be surplus to defense needs in the coming decades; and (d) the opening of the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico in 1999.

none,

2012-06-01

402

ESTIMATING IMPURITIES IN SURPLUS PLUTONIUM FOR DISPOSITION  

SciTech Connect

The United States holds at least 61.5 metric tons (MT) of plutonium that is permanently excess to use in nuclear weapons programs, including 47.2 MT of weapons-grade plutonium. Surplus inventories will be stored safely by the Department of Energy (DOE) and then transferred to facilities that will prepare the plutonium for permanent disposition. The Savannah River National Laboratory (SRNL) operates a Feed Characterization program for the Office of Fissile Materials Disposition of the National Nuclear Security Administration and the DOE Office of Environmental Management. Many of the items that require disposition are only partially characterized, and SRNL uses a variety of techniques to predict the isotopic and chemical properties that are important for processing through the Mixed Oxide Fuel Fabrication Facility and alternative disposition paths. Recent advances in laboratory tools, including Prompt Gamma Analysis and Peroxide Fusion treatment, provide data on the existing inventories that will enable disposition without additional, costly sampling and destructive analysis.

Allender, J.; Moore, E.

2013-07-17

403

Extraction of uranyl, La(III), and Y(III) nitrates with a composite solid extractant based on a polymeric support impregnated with trialkylamine  

Microsoft Academic Search

Extraction of uranyl, La(III), and Y(III) nitrates from aqueous solutions containing 0–4 M sodium nitrate with a composite\\u000a solid extractant based on a polymeric support impregnated with trialkylamine (C7-C9) was studied. The extraction isotherms were analyzed assuming that La(III), Y(III), and uranyl nitrates are extracted with\\u000a the solid extractant in the form of complexes (R3NH)3[Ln(NO3)6] and (R3NH)2[UO2(NO3)4], respectively. The extraction

A. K. Pyartman; V. V. Lishchuk; V. A. Keskinov

2007-01-01

404

REVIEW OF PLUTONIUM OXIDATION LITERATURE  

SciTech Connect

A brief review of plutonium oxidation literature was conducted. The purpose of the review was to ascertain the effect of oxidation conditions on oxide morphology to support the design and operation of the PDCF direct metal oxidation (DMO) furnace. The interest in the review was due to a new furnace design that resulted in oxide characteristics that are different than those of the original furnace. Very little of the published literature is directly relevant to the DMO furnace operation, which makes assimilation of the literature data with operating conditions and data a convoluted task. The oxidation behavior can be distilled into three regimes, a low temperature regime (RT to 350 C) with a relatively slow oxidation rate that is influenced by moisture, a moderate temperature regime (350-450 C) that is temperature dependent and relies on more or less conventional oxidation growth of a partially protective oxide scale, and high temperature oxidation (> 500 C) where the metal autocatalytically combusts and oxidizes. The particle sizes obtained from these three regimes vary with the finest being from the lowest temperature. It is surmised that the slow growth rate permits significant stress levels to be achieved that help break up the oxides. The intermediate temperatures result in a fairly compact scale that is partially protective and that grows to critical thickness prior to fracturing. The growth rate in this regime may be parabolic or paralinear, depending on the oxidation time and consequently the oxide thickness. The high temperature oxidation is invariant in quiescent or nearly quiescent conditions due to gas blanketing while it accelerates with temperature under flowing conditions. The oxide morphology will generally consist of fine particles (<15 {micro}m), moderately sized particles (15 < x < 250 {micro}m) and large particles (> 250 {micro}m). The particle size ratio is expected to be < 5%, 25%, and 70% for fine, medium and large particles, respectively, for metal temperatures in the 500-600 C range.

Korinko, P.

2009-11-12

405

Study of the formation, prevention, and recovery of plutonium from plutonium esters in the Purex process  

SciTech Connect

The Savannah River Plant uses the basic Purex process to separate /sup 239/Pu from /sup 238/U and fission products. Dark-brown, dense solids containing up to 30% Pu have previously occurred in rotameters in the plutonium finishing operations. The kinetics of formation of this mixture of DBP- and MBP-Pu esters suggest two methods to prevent the formation of the solids. A selective dissolution method using NaOH metathesis has been developed to separate the phosphate ester from the plutonium before dissolution of the residual plutonium hydroxide in a HNO/sub 3/-HF medium.

Gray, L. W.; Burney, G. A.

1981-01-01

406

Plutonium scrap recovery at Savannah River: Past, present, and vision of the future  

SciTech Connect

As a result of the changing requirement, plus environmental and regulatory commitments, SRP now has essentially completed its paradigm shift. SRP has been transformed from primarily a reprocessor of irradiated uranium targets to primarily a reprocessor of non-specification plutonium. This is the mission which will carry SRP into the 21st Century. Accomplishment of the defined goals for the three-pronged RandD program will achieve several objectives: exploit new processes for recovering low-grade scraps; enhance SRP's position to incorporate pyrochemical processes where they are attractive or beneficial to plant scrap recovery; provide SRL/SRP with a capability to develop compatible aqueous pyrochemical processes; identify material compatibility requirements for the incorporation of pyrochemical processes at SRP; promote development and demonstration of improved NDA instrumentation to accurately measure plutonium holdups in solid residues; identify and implement the technology required for reagent preparation and atmospheric quality control; provide a means to compare economic options for emerging new processes; and as a result, identify process steps which will also put SRP in a position to readily adapt to changing plutonium missions.

Gray, L.W.; Gray, J.H.; Blancett, A.L.; Lower, M.W.; Rudisill, T.S.

1988-01-01

407

Disposition of Mixed Waste Organics at the Los Alamos Plutonium Facility  

SciTech Connect

Twenty-six organic solution items totaling 37 L had been stored in the Plutonium Facility vault at the Los Alamos National Laboratory, some for up to 18 years. They were residues from analytical analyses of radioactive solutions. All items had a Resource Conservation and Recovery Act (RCRA) defined hazardous waste combined with special nuclear materials (SNM) and were stored as a mixed waste in a vault room pending disposition. Seventeen items had plutonium concentrations above established discard limits for organics. Due to their age, the containers were not suitable for long-term storage because a container failure would contaminate the vault area and personnel. Therefore, an aqueous-based flowsheet was developed to remove the plutonium so that the items could be discarded. The procedure was a wash with either sodium fluoride and/or potassium hydroxide solution followed by absorbing the discardable organic residues on vermiculite. When this approach did not work permission was obtained to discard the items as a transuranic (TRU) mixed waste without further treatment. The remaining nine solution items were consolidated into two items, repackaged, and stored for future disposition. The overall effort required approximately four months to disposition all the items. This report details the administrative and regulatory requirements that had to be addressed, the results of processing, and the current status of the items.

Ortiz, E.M.; Coriz, F.; Schreiber, S.B.; Balkey, S.; Yarbro, S.L.

1999-02-01

408

Nitrate Reduction Functional Genes and Nitrate Reduction Potentials Persist in Deeper Estuarine Sediments. Why?  

PubMed Central

Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are processes occurring simultaneously under oxygen-limited or anaerobic conditions, where both compete for nitrate and organic carbon. Despite their ecological importance, there has been little investigation of how denitrification and DNRA potentials and related functional genes vary vertically with sediment depth. Nitrate reduction potentials measured in sediment depth profiles along the Colne estuary were in the upper range of nitrate reduction rates reported from other sediments and showed the existence of strong decreasing trends both with increasing depth and along the estuary. Denitrification potential decreased along the estuary, decreasing more rapidly with depth towards the estuary mouth. In contrast, DNRA potential increased along the estuary. Significant decreases in copy numbers of 16S rRNA and nitrate reducing genes were observed along the estuary and from surface to deeper sediments. Both metabolic potentials and functional genes persisted at sediment depths where porewater nitrate was absent. Transport of nitrate by bioturbation, based on macrofauna distributions, could only account for the upper 10 cm depth of sediment. A several fold higher combined freeze-lysable KCl-extractable nitrate pool compared to porewater nitrate was detected. We hypothesised that his could be attributed to intracellular nitrate pools from nitrate accumulating microorganisms like Thioploca or Beggiatoa. However, pyrosequencing analysis did not detect any such organisms, leaving other bacteria, microbenthic algae, or foraminiferans which have also been shown to accumulate nitrate, as possible candidates. The importance and bioavailability of a KCl-extractable nitrate sediment pool remains to be tested. The significant variation in the vertical pattern and abundance of the various nitrate reducing genes phylotypes reasonably suggests differences in their activity throughout the sediment column. This raises interesting questions as to what the alternative metabolic roles for the various nitrate reductases could be, analogous to the alternative metabolic roles found for nitrite reductases.

Papaspyrou, Sokratis; Smith, Cindy J.; Dong, Liang F.; Whitby, Corinne; Dumbrell, Alex J.; Nedwell, David B.

2014-01-01

409

Nitrate reduction functional genes and nitrate reduction potentials persist in deeper estuarine sediments. Why?  

PubMed

Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are processes occurring simultaneously under oxygen-limited or anaerobic conditions, where both compete for nitrate and organic carbon. Despite their ecological importance, there has been little investigation of how denitrification and DNRA potentials and related functional genes vary vertically with sediment depth. Nitrate reduction potentials measured in sediment depth profiles along the Colne estuary were in the upper range of nitrate reduction rates reported from other sediments and showed the existence of strong decreasing trends both with increasing depth and along the estuary. Denitrification potential decreased along the estuary, decreasing more rapidly with depth towards the estuary mouth. In contrast, DNRA potential increased along the estuary. Significant decreases in copy numbers of 16S rRNA and nitrate reducing genes were observed along the estuary and from surface to deeper sediments. Both metabolic potentials and functional genes persisted at sediment depths where porewater nitrate was absent. Transport of nitrate by bioturbation, based on macrofauna distributions, could only account for the upper 10 cm depth of sediment. A several fold higher combined freeze-lysable KCl-extractable nitrate pool compared to porewater nitrate was detected. We hypothesised that his could be attributed to intracellular nitrate pools from nitrate accumulating microorganisms like Thioploca or Beggiatoa. However, pyrosequencing analysis did not detect any such organisms, leaving other bacteria, microbenthic algae, or foraminiferans which have also been shown to accumulate nitrate, as possible candidates. The importance and bioavailability of a KCl-extractable nitrate sediment pool remains to be tested. The significant variation in the vertical pattern and abundance of the various nitrate reducing genes phylotypes reasonably suggests differences in their activity throughout the sediment column. This raises interesting questions as to what the alternative metabolic roles for the various nitrate reductases could be, analogous to the alternative metabolic roles found for nitrite reductases. PMID:24728381

Papaspyrou, Sokratis; Smith, Cindy J; Dong, Liang F; Whitby, Corinne; Dumbrell, Alex J; Nedwell, David B

2014-01-01

410

Waste measurements at a plutonium facility  

SciTech Connect

Solid plutonium contaminated wastes are often highly heterogeneous, span a wide range of chemical compositions and matrix types, and are packaged in a variety of container sizes. NDA analysis of this waste depends on operator knowledge of these parameters so that proper segregation, instrument selection, quality assurance, and uncertainty estimation can take place. This report describes current waste measurement practices and uncertainty estimates at a US plutonium scrap recovery facility and presents a program for determining reproducibility and bias in NDA measurements. Following this, an operator's perspective on desirable NDA upgrades is offered.

Wachter, J.R.

1992-01-01

411

Waste measurements at a plutonium facility  

SciTech Connect

Solid plutonium contaminated wastes are often highly heterogeneous, span a wide range of chemical compositions and matrix types, and are packaged in a variety of container sizes. NDA analysis of this waste depends on operator knowledge of these parameters so that proper segregation, instrument selection, quality assurance, and uncertainty estimation can take place. This report describes current waste measurement practices and uncertainty estimates at a US plutonium scrap recovery facility and presents a program for determining reproducibility and bias in NDA measurements. Following this, an operator`s perspective on desirable NDA upgrades is offered.

Wachter, J.R.

1992-06-01

412

Fluorination of incinerator ash by hydrofluorination or ammonium bifluoride fusion for plutonium recovery  

SciTech Connect

Incinerator ash containing small quantities of plutonium has been accumulating across the defense complex for many years. Although the total Pu inventory is small, the ash is a nondiscardable residue which presents storage and accountability difficulties. The work discussed here is the result of a joint exploratory effort between members of Savannah River Laboratory and Los Alamos National Laboratory to compare two proposed pyrochemical pretreatments of incinerator ash prior to aqueous processing. These experiments attempted to determine the relative effectiveness of hydrofluorination and ammonium bifluoride fusion as head-end operations for a two step aqueous recovery method. The two pretreatments are being considered as possible second generation enhancements for the New Special Recovery Facility nearing operation at Savannah River Plant. Experimental results and potential engineering concerns are discussed. 3 figs.

Fink, S.D.; Gray, J.H.; Kent, S.J.; Apgar, S.A.

1989-01-01

413

Process for Recovery of Plutonium from Fabrication Residues of Mixed Fuels Consisting of Uranium Oxide and Plutonium Oxide.  

National Technical Information Service (NTIS)

The invention concerns a process for recovery of plutonium from fabrication residues of mixed fuels consisting of uranium oxide and plutonium oxide in the form of PuO sub 2 . Mixed fuels consisting of uranium oxide and plutonium oxide are being used more ...

R. H. Heremanns J. J. Vandersteene

1983-01-01

414

Modeling of Diffusion of Plutonium in Other Metals and of Gaseous Species in Plutonium-Based Systems  

SciTech Connect

Establish standards for temperature conditions under which plutonium, uranium, or neptunium from nuclear wastes permeates steel, with which it is in contact, by diffusion processes. The primary focus is on plutonium because of the greater difficulties created by the peculiarities of face-centered-cubic-stabilized (delta) plutonium (the form used in the technology generating the waste).

Bernard R. Cooper; Gayanath W. Fernando; S. Beiden; A. Setty; E.H. Sevilla

2004-07-02

415

Environmentally Responsible Use of Nanomaterials for the Photocatalytic Reduction of Nitrate in Water  

NASA Astrophysics Data System (ADS)

Nitrate is the most prevalent water pollutant limiting the use of groundwater as a potable water source. The overarching goal of this dissertation was to leverage advances in nanotechnology to improve nitrate photocatalysis and transition treatment to the full-scale. The research objectives were to (1) examine commercial and synthesized photocatalysts, (2) determine the effect of water quality parameters (e.g., pH), (3) conduct responsible engineering by ensuring detection methods were in place for novel materials, and (4) develop a conceptual framework for designing nitrate-specific photocatalysts. The key issues for implementing photocatalysis for nitrate drinking water treatment were efficient nitrate removal at neutral pH and by-product selectivity toward nitrogen gases, rather than by-products that pose a human health concern (e.g., nitrite). Photocatalytic nitrate reduction was found to follow a series of proton-coupled electron transfers. The nitrate reduction rate was limited by the electron-hole recombination rate, and the addition of an electron donor (e.g., formate) was necessary to reduce the recombination rate and achieve efficient nitrate removal. Nano-sized photocatalysts with high surface areas mitigated the negative effects of competing aqueous anions. The key water quality parameter impacting by-product selectivity was pH. For pH < 4, the by-product selectivity was mostly N-gas with some NH4 +, but this shifted to NO2- above pH = 4, which suggests the need for proton localization to move beyond NO2 -. Co-catalysts that form a Schottky barrier, allowing for localization of electrons, were best for nitrate reduction. Silver was optimal in heterogeneous systems because of its ability to improve nitrate reduction activity and N-gas by-product selectivity, and graphene was optimal in two-electrode systems because of its ability to shuttle electrons to the working electrode. "Environmentally responsible use of nanomaterials" is to ensure that detection methods are in place for the nanomaterials tested. While methods exist for the metals and metal oxides examined, there are currently none for carbon nanotubes (CNTs) and graphene. Acknowledging that risk assessment encompasses dose-response and exposure, new analytical methods were developed for extracting and detecting CNTs and graphene in complex organic environmental (e.g., urban air) and biological matrices (e.g. rat lungs).

Doudrick, Kyle

416

The contributions of nitrate uptake and efflux to isotope fractionation during algal nitrate assimilation  

NASA Astrophysics Data System (ADS)

In order to strengthen environmental application of nitrate N and O isotopes, we measured the N and O isotopic fractionation associated with cellular nitrate uptake and efflux in the nitrate-assimilating marine diatom Thalassiosira weissflogii. We isolated nitrate uptake and efflux from nitrate reduction by growing the cells in the presence of tungsten, which substitutes for molybdenum in assimilatory nitrate reductase, yielding an inactive enzyme. After growth on ammonium and then N starvation, cells were exposed to nitrate. Numerical models fit to the evolution of intracellular nitrate concentration and N and O isotopic composition yielded distinct N isotope effects (15?) for nitrate uptake and nitrate efflux (2.0 ± 0.3‰ and 1.2 ± 0.4‰, respectively). The O isotope effects (18?) for nitrate uptake and nitrate efflux were indistinguishable (2.8 ± 0.6‰), yielding a ratio of O to N isotopic fractionation for uptake of 1.4 ± 0.4 and for efflux of 2.3 ± 0.9. The 15? for nitrate uptake can account for at most 40% of the organism-level N isotope effect (15?org) measured in laboratory studies of T. weissflogii and in the open ocean (typically 5‰ or greater). This observation supports previous evidence that most isotope fractionation during nitrate assimilation is due to intracellular nitrate reduction, with nitrate efflux allowing the signal to be communicated to the environment. An O to N fractionation ratio (18?org:15?org) of ˜1 has been measured for nitrate assimilation in algal cultures and linked to the N and O isotope effects of nitrate reductase. Our results suggest that the ratios of O to N fractionation for both nitrate uptake and efflux may be distinct from a ratio of 1, to a degree that could cause the net 18?org:15?org to rise appreciably above 1 when 15?org is low (e.g., yielding a ratio of 1.1 when 15?org is 5‰). However, field and culture studies have consistently measured nearly equivalent fractionation of N and O isotopes in association with low isotope effects, calling for isotopic studies of nitrate transport by other phytoplankton strains.

Karsh, K. L.; Trull, T. W.; Sigman, D. M.; Thompson, P. A.; Granger, J.

2014-05-01

417

21 CFR 172.170 - Sodium nitrate.  

Code of Federal Regulations, 2013 CFR

...HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD...172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in...product. (b) To assure safe use of the additive, in addition to the other...

2013-04-01

418

Desensitizer for N-Propyl Nitrate.  

National Technical Information Service (NTIS)

According to this invention, n-propyl nitrate is rendered insensitive to shock, i.e., is desensitized, by means of a low gamma gas. The low gamma gas is incorporated into the n-propyl nitrate in an amount sufficient to assure that when bubbles are formed ...

B. A. Breslow

1976-01-01

419

COMPARTMENTAL MODEL OF NITRATE RETENTION IN STREAMS  

EPA Science Inventory

A compartmental modeling approach is presented to route nitrate retention along a cascade of stream reach sections. A process transfer function is used for transient storage equations with first order reaction terms to represent nitrate uptake in the free stream, and denitrifica...

420

Nitrate reductase in Peru current phytoplankton  

Microsoft Academic Search

Nitrate reductase (NR) activity was assayed by measuring the NADH-dependent formation of nitrite in phytoplankton extracts. NR specific activity increased with the nitrate concentration of the water in upwelling areas of the Peru Current. The temperature optimum for NR for natural phytoplankton was 15° to 20°C. NR activity showed diel periodicity, with maximum activity about noon and minimum activity near

R. W. Eppley; T. T. Packard; J. J. MacIsaac

1970-01-01

421

HEALTH EFFECTS OF NITRATES IN WATER  

EPA Science Inventory

A multi faceted study of the health effects of nitrate in drinking water using epidemiological and toxicological techniques is reported. The results of the epidemiological studies indicate that infants consuming appreciable amounts of water high in nitrates in the form of powdere...

422

Energy transfer in crystalline alkali nitrates  

NASA Astrophysics Data System (ADS)

The radiation annealing of peroxynitrite ions in pre-photolyzed (253.7 nm) alkali nitrate crystals has been studied. This process is stated to be due to interaction with high-energy excited states of the nitrate ion symmetry E' than to low-energy excited states symmetry A1?. The distance of energy transfer has been found to be ˜10 nm.

Anan'ev, Vladimir

2007-08-01

423

Winter Wheat Fertilization: Post Ammonium Nitrate  

Microsoft Academic Search

Summary The potential for overwinter losses of nitrogen by denitrification and leaching have led to the recommendation that nitrogen fertilization of winter wheat be done using ammonium nitrate broadcast in the spring. However, spring broadcast application of urea can result in significant loss of nitrogen by volatilization and immobilization by surface residues. Since prilled ammonium nitrate is not available for

R. Byron Irvine; Guy Lafond; Randy Kutcher

424

46 CFR 148.227 - Calcium nitrate fertilizers.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Calcium nitrate fertilizers. 148.227...Certain Materials § 148.227 Calcium nitrate fertilizers. This part does not apply to commercial grades of calcium nitrate fertilizers consisting...

2013-10-01

425

SAMPLING AND ANALYTICAL METHODOLOGY FOR ATMOSPHERIC PARTICULATE NITRATES  

EPA Science Inventory

Environmental conditions that affect atmospheric particulate nitrate sampling were identified, and improved sampling and analytical procedures were developed. Evaluation of potential sources of error in high volume nitrate sampling showed that artifact nitrate formation on common...

426

Dissolution of Plutonium Metal Using a HAN Process  

SciTech Connect

Thermal stability tests were conducted with a nitric acid (HNO3)/hydroxylammonium nitrate (HAN)/potassium fluoride (KF) solution. The solution has great potential for use in plutonium dissolution because of the small quantity of hydrogen and other offgases produced. Tests were carried out in a Reactive Systems Screening Tool (RSST). The RSST is a calorimeter equipped with temperature and pressure probes as well as a heater that can heat a liquid sample at a programmed rate. In most cases, the calorimeter was pressurized with nitrogen to reduce evaporation of the liquid sample during heating. For the proposed solution, an autocatalytic reaction occurred between 113 and 131 degrees Celsius with 300 psig or 50 psig nitrogen inside the RSST vapor space. At ambient pressure, the solution boiled at about 110 degrees Celsius. After extensive boiling, the concentrations of HNO3 and HAN increased and the autocatalytic reaction occurred. Tests were also conducted with 1000 ppm Fe present in the solution. The range of the autocatalytic reaction initiation temperature was reduced to 105-120.5 degrees Celsius. With iron at ambient pressure, boiling still occurred above 100 degrees Celsius prior to the autocatalytic reaction, which occurred at 108-109 degrees Celsius. These results demonstrated the stability of the proposed HAN flowsheet, for which the planned dissolving temperature is 50-60 degrees Celsius. Additional tests were carried out with more concentrated solutions to further characterize the autocatalytic reaction initiation temperature. Increasing the nitric acid concentration to 3M decreased the reaction initiation temperature to 102-103 degrees Celsius. Increasing the HAN concentration increased the temperature rise of the reaction from 10-30 degrees Celsius to greater than 40 degrees Celsius. Increasing both reactants-to 3M nitric acid and 0.9M HAN-yielded a reaction initiation temperature of 91 degrees Celsius (with or without iron), the lowest observed in this study. This study was the first part of a larger flowsheet development / demonstration program for the plutonium metal dissolving process. The results of the study may be useful for similar flowsheets.

CROWDER, MARKL.

2004-06-30

427

Excess Weapons Plutonium Disposition: Plutonium Packaging, Storage and Transportation and Waste Treatment, Storage and Disposal Activities  

SciTech Connect

A fifth annual Excess Weapons Plutonium Disposition meeting organized by Lawrence Livermore National Laboratory (LLNL) was held February 16-18, 2004, at the State Education Center (SEC), 4 Aerodromnya Drive, St. Petersburg, Russia. The meeting discussed Excess Weapons Plutonium Disposition topics for which LLNL has the US Technical Lead Organization responsibilities. The technical areas discussed included Radioactive Waste Treatment, Storage, and Disposal, Plutonium Oxide and Plutonium Metal Packaging, Storage and Transportation and Spent Fuel Packaging, Storage and Transportation. The meeting was conducted with a conference format using technical presentations of papers with simultaneous translation into English and Russian. There were 46 Russian attendees from 14 different Russian organizations and six non-Russian attendees, four from the US and two from France. Forty technical presentations were made. The meeting agenda is given in Appendix B and the attendance list is in Appendix C.

Jardine, L J; Borisov, G B

2004-07-21

428

Phase diagram of ammonium nitrate.  

PubMed

Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO-AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N2, N2O, and H2O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV' transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C. PMID:24320387

Dunuwille, Mihindra; Yoo, Choong-Shik

2013-12-01

429

Pseudo-constitutivity of nitrate-responsive genes in nitrate reductase mutants  

PubMed Central

In fungi, transcriptional activation of genes involved in NO3- assimilation requires the presence of an inducer (nitrate or nitrite) and low intracellular concentrations of the pathway products ammonium or glutamine. In Aspergillus nidulans, the two transcription factors NirA and AreA act synergistically to mediate nitrate/nitrite induction and nitrogen metabolite derepression, respectively. In all studied fungi and in plants, mutants lacking nitrate reductase (NR) activity express nitrate-metabolizing enzymes constitutively without the addition of inducer molecules. Based on their work in A. nidulans, Cove and Pateman proposed an “autoregulation control” model for the synthesis of nitrate metabolizing enzymes in which the functional nitrate reductase molecule would act as co-repressor in the absence and as co-inducer in the presence of nitrate. However, NR mutants could simply show “pseudo-constitutivity” due to induction by nitrate which accumulates over time in NR-deficient strains. Here we examined this possibility using strains which lack flavohemoglobins (fhbs), and are thus unable to generate nitrate internally, in combination with nitrate transporter mutations (nrtA, nrtB) and a GFP-labeled NirA protein. Using different combinations of genotypes we demonstrate that nitrate transporters are functional also in NR null mutants and show that the constitutive phenotype of NR mutants is not due to nitrate accumulation from intracellular sources but depends on the activity of nitrate transporters. However, these transporters are not required for nitrate signaling because addition of external nitrate (10 mM) leads to standard induction of nitrate assimilatory genes in the nitrate transporter double mutants. We finally show that NR does not regulate NirA localization and activity, and thus the autoregulation model, in which NR would act as a co-repressor of NirA in the absence of nitrate, is unlikely to be correct. Results from this study instead suggest that transporter-mediated NO3- accumulation in NR deficient mutants, originating from traces of nitrate in the media, is responsible for the constitutive expression of NirA-regulated genes, and the associated phenotype is thus termed “pseudo-constitutive”.

Schinko, Thorsten; Gallmetzer, Andreas; Amillis, Sotiris; Strauss, Joseph

2013-01-01

430

Weapons-grade plutonium dispositioning. Volume 2: Comparison of plutonium disposition options  

SciTech Connect

The Secretary of Energy requested the National Academy of Sciences (NAS) Committee on International Security and Arms Control to evaluate disposition options for weapons-grade plutonium. The Idaho National Engineering Laboratory (INEL) offered to assist the NAS in this evaluation by investigating the technical aspects of the disposition options and their capability for achieving plutonium annihilation levels greater than 90%. This report was prepared for the NAS to document the gathered information and results from the requested option evaluations. Evaluations were performed for 12 plutonium disposition options involving five reactor and one accelerator-based systems. Each option was evaluated in four technical areas: (1) fuel status, (2) reactor or accelerator-based system status, (3) waste-processing status, and (4) waste disposal status. Based on these evaluations, each concept was rated on its operational capability and time to deployment. A third rating category of option costs could not be performed because of the unavailability of adequate information from the concept sponsors. The four options achieving the highest rating, in alphabetical order, are the Advanced Light Water Reactor with plutonium-based ternary fuel, the Advanced Liquid Metal Reactor with plutonium-based fuel, the Advanced Liquid Metal Reactor with uranium-plutonium-based fuel, and the Modular High Temperature Gas-Cooled Reactor with plutonium-based fuel. Of these four options, the Advanced Light Water Reactor and the Modular High Temperature Gas-Cooled Reactor do not propose reprocessing of their irradiated fuel. Time constraints and lack of detailed information did not allow for any further ratings among these four options. The INEL recommends these four options be investigated further to determine the optimum reactor design for plutonium disposition.

Brownson, D.A.; Hanson, D.J.; Blackman, H.S. [and others

1993-06-01

431

Fifty years of plutonium exposure to the Mahattan Project plutonium workers: An update  

Microsoft Academic Search

Twenty-six white male workers who did the original plutonium research and development work at Los Alamos have been examined periodically over the past 50 y to identify possible health effects from internal plutonium depositions. Their effective doses range from 0.1 to 7.2 Sv with a median value of 1.25 Sv. As of the end of 1994, 7 individuals have died

George L. Voelz; James N. P. Lawrence; Emily R. Johnson

1997-01-01

432

Effect of Americium-241 Content on Plutonium Radiation Source Terms  

SciTech Connect

The management of excess plutonium by the US Department of Energy includes a number of storage and disposition alternatives. Savannah River Site (SRS) is supporting DOE with plutonium disposition efforts, including the immobilization of certain plutonium materials in a borosilicate glass matrix. Surplus plutonium inventories slated for vitrification include materials with elevated levels of Americium-241. The Am-241 content of plutonium materials generally reflects in-growth of the isotope due to decay of plutonium and is age-dependent. However, select plutonium inventories have Am-241 levels considerably above the age-based levels. Elevated levels of americium significantly impact radiation source terms of plutonium materials and will make handling of the materials more difficult. Plutonium materials are normally handled in shielded glove boxes, and the work entails both extremity and whole body exposures. This paper reports results of an SRS analysis of plutonium materials source terms vs. the Americium-241 content of the materials. Data with respect to dependence and magnitude of source terms on/vs. Am-241 levels are presented and discussed. The investigation encompasses both vitrified and un-vitrified plutonium oxide (PuO2) batches.

Rainisch, R.

1998-12-28

433

Photolytic destruction of oxalate in aqueous mixed waste  

SciTech Connect

In aqueous plutonium processing, residual oxalic acid can be destroyed (oxalate kill) by UV light with hydrogen peroxide (H{sub 2}O{sub 2}) in 1 M HCl solutions. By controlling the amount of H{sub 2}O{sub 2}, the oxalate kill process will not affect the chloride concentration. In nitric acid solutions, UV light alone can destroy the oxalic acid. However, with H{sub 2}O{sub 2}, the rate of destruction is faster. After the destruction of oxalic acid, the acidic solutions may be reusable without further purification process.

Wang, F.T.; Lum, B.Y.

1995-03-01

434

NNSS Soils Monitoring: Plutonium Valley (CAU366)  

SciTech Connect

The U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA), Nevada Site Office (NSO), Environmental Restoration Soils Activity has authorized the Desert Research Institute (DRI) to conduct field assessments of potential sediment transport of contaminated soil from Corrective Action Unit (CAU) 366, Area 11 Plutonium Valley Dispersion Sites Contamination Area (CA) during precipitation runoff events.

Miller Julianne J.,Mizell Steve A.,Nikolich George, Campbell Scott

2012-02-01

435

Plutonium-no supply, no demand  

Microsoft Academic Search

The article discusses arms control in light of recent world developments, and indicates that an old arms control idea, to stop making the fissile material used in nuclear weapons, has found new life in congress. The status of the International Plutonium Control Act in the congress is discussed. A brief history is provided of proposals to halt production of the

Lanouette

1989-01-01

436

Plutonium to Uranium Fission Ratio Measurements.  

National Technical Information Service (NTIS)

The measurement of the ratio of plutonium to uranium fissions has for some years been used as a method of characterizing the thermal spectrum in reactor lattices. This report describes the method of analysis of this type of measurement which has been deve...

R. H. Waterson

1971-01-01

437

EPRI Programs on Plutonium Fuel Utilization.  

National Technical Information Service (NTIS)

EPRI has initiated a plutonium recycle program with a goal of providing a technical base for the industry to consider in choosing among the various available alternatives. Basic criteria for Pu recycle will be made by the individual user, subject to Unite...

B. A. Zolotar M. E. Lapides F. E. Gelhaus

1975-01-01

438

PLUTONIUM SPECIATION, SOLUBILIZATION, AND MIGRATION IN SOILS  

EPA Science Inventory

The DOE is currently conducting cleanup activities at its nuclear weapons development sites, many of which have accumulated plutonium (Pu) in soils for 50 years. There is scientific uncertainty about the levels of risk to human health posed by this accumulation and whether Pu is ...

439

Development of the plutonium oxide vitrification system  

SciTech Connect

Repository disposal of plutonium in a suitable, immobilized form is being considered as one option for the disposition of surplus weapons-usable plutonium. Accelerated development efforts were completed in 1997 on two potential immobilization forms to facilitate downselection to one form for continued development. The two forms studied were a crystalline ceramic based on Synroc technology and a lanthanide borosilicate (LaBS) glass. As part of the glass development program, melter design activities and component testing were completed to demonstrate the feasibility of using glass as an immobilization medium. A prototypical melter was designed and built in 1997. The melter vessel and drain tube were constructed of a Pt/Rh alloy. Separate induction systems were used to heat the vessel and drain tube. A Pt/Rh stirrer was incorporated into the design to facilitate homogenization of the melt. Integrated powder feeding and off-gas systems completed the overall design. Concurrent with the design efforts, testing was conducted using a plutonium surrogate LaBS composition in an existing (near-scale) melter to demonstrate the feasibility of processing the LaBS glass on a production scale. Additionally, the drain tube configuration was successfully tested using a plutonium surrogate LaBS glass.

Marshall, K.M.; Marra, J.C.; Coughlin, J.T.; Calloway, T.B.; Schumacher, R.F.; Zamecnik, J.R.; Pareizs, J.M.

1998-01-01

440

Physical Property Changes in Aging Plutonium Alloys  

SciTech Connect

Plutonium, because of its self-irradiation by alpha decay, ages by means of lattice damage and helium in-growth. These integrated aging effects result in microstructural and physical property changes. Because these effects would normally require decades to measure, studies are underway to asses the effects of extended aging on the physical properties of plutonium alloys by incorporating roughly 7.5 wt% of highly specific activity isotope {sup 238}Pu into weapons-grade plutonium to accelerate the aging process. This paper presents updated results of self-irradiation effects on enriched and reference alloys measured from immersion density, dilatometry, and mechanical tests. After nearly 90 equivalent years of aging, both the immersion density and dilatometry show that the enriched alloys at 35 deg. C have decreased in density by {approx}0.19% and now exhibit a near linear density decrease, without void swelling. Both tensile and compression measurements show that the aging process continues to increase the strength of plutonium alloys. (authors)

Chung, Brandon W.; Thompson, Stephen R.; Hiromoto, David S. [Lawrence Livermore National Laboratory, Livermore, CA, 94551 (United States)

2008-07-01

441

Measurements of plutonium residues from recovery processes  

Microsoft Academic Search

Conventional methods of nondestructive assay (NDA) have accurately assayed the plutonium content of many forms of relatively pure and homogeneous bulk items. However, physical and chemical heterogeneities and the high and variable impurity levels of many categories of processing scrap bias the conventional NDA results. The materials also present a significant challenge to the assignment of reference values to process

S.-T. Hsue; D. G. Langner; V. L. Longmire; H. O. Menlove; P. A. Russo; J. K. Jr. Sprinkle

1989-01-01

442

Adsorption and Diffusion of Plutonium in Soil.  

National Technical Information Service (NTIS)

The behavior of plutonium (Pu) was studied in three soils that varied in texture, CEC, pH, organic matter content and mineralogy (Fuquay, Muscatine, Burbank). Two isotopes, exp 238 Pu and exp 239 Pu, were used in order to detect Pu over a range of several...

D. A. Brown

1980-01-01

443

Experience of Plutonium Recycle in Italy.  

National Technical Information Service (NTIS)

This paper describes the experimental work undertaken in Italy on the irradiation of plutonium bearing fuel in thermal reactors. 16 MOX fuel assemblies were initially loaded into the Garigliano BWR and a further 46, a full reload, were loaded in 1975. Eig...

A. Ariemma C. Lepscky F. Pistella G. Testa G. M. Paoletti

1978-01-01

444

Bacteria and plutonium in marine environments  

Microsoft Academic Search

Microbes are important in geochemical cycling of many elements. Recent reports emphasize biogenous particulates and bacterial exometabolites as controlling oceanic distribution of plutonium. Bacteria perform oxidation\\/reduction reactions on metals such as mercury, nickel, lead, copper, and cadmium. Redox transformations or uptake of Pu by marine bacteria may well proceed by similar mechanisms. Profiles of water samples and sediment cores were

A. E. Carey; V. T. Bowen

1978-01-01

445

Plutonium oxide polishing for MOX fuel fabrication  

Microsoft Academic Search

Los Alamos National Laboratory (LANL) successfully polished 120kg of plutonium from surplus nuclear weapons for the European Mixed Oxide (MOX) Lead Test Assembly (LTA), managed by Duke, COGEMA, and Stone & Webster (DCS). The purified oxide was fabricated into fuel pellets, which comprised the LTAs. The LTAs have been inserted into the Catawba (SC, USA) nuclear reactor, where they are

Jennifer Louise Alwin; Fawn Coriz; Jan A. Danis; Brian K. Bluhm; David W. Wayne; Devin W. Gray; Kevin B. Ramsey; David A. Costa; Elizabeth A. Bluhm; Archie E. Nixon; Daniel J. Garcia; Judy D. Roybal; Mark T. Saba; Jose A. Valdez; David Martinez; Joe R. Martinez; Cathy M. Martinez; Yvonne A. Martinez; Carl M. Martinez

2007-01-01

446

Plutonium Management in the Medium Term  

SciTech Connect

For many years various countries with access to commercial reprocessing services have been routinely recycling plutonium as UO{sub 2}/PuO{sub 2} mixed oxide (MOX) fuel in light water reactors (LWRs). This LWR MOX recycle strategy is still widely regarded as an interim step leading to the eventual establishment of sustainable fast reactor fuel cycles. The OECD/NEA Working Party on the Physics of Plutonium Fuels and Innovative Fuel Cycles (WPPR) has recently completed a review of the technical options for plutonium management in what it refers to as the 'medium term'. For the purpose of the review, the WPPR considers the medium term to cover the period from now up to the point at which fast reactor fuel cycles are established on a commercial scale. The review identified a number of different designs of innovative plutonium fuel assemblies intended to be used in current LWR cores, in LWRs with significantly different moderation properties, as well as in high-temperature gas reactors. The full review report describes these various options and highlights their respective advantages and disadvantages. This paper briefly summarizes the main findings of the review.

Hesketh, Kevin [BNFL Nuclear Sciences and Technology Services (United Kingdom); Schlosser, Gerhard; Porsch, Dieter F. [Framatome ANP (France); Wolf, Timm [Framatome ANP (France); Koeberl, Oliver [CEA Cadarache (France); Lance, Benoit [Belgonucleaire (Belgium); Chawla, Rakesh [Paul Scherrer Institut (Switzerland); Gehin, Jess C. [Oak Ridge National Laboratory (United States); Ellis, Ron [Oak Ridge National Laboratory (United States); Uchikawa, Sadao [Japan Atomic Energy Research Institute (Japan); Sato, Osamu [Japan Atomic Energy Research Institute (Japan); Okubo, Tsutomu [Japan Atomic Energy Research Institute (Japan); Mineo, Hideaki [Japan Atomic Energy Research Institute (Japan); Yamamoto, Toru [Nuclear Power Engineering Corporation (Japan); Sagayama, Yutaka [Japan Nuclear Cycle Development Institute (Japan); Sartori, Enrico [Organization for Economic Cooperation and Development (France)

2004-12-15

447

Analysis of femtogram-sized plutonium samples  

SciTech Connect

This report describes a study to determine how well isotopic ratios can be measured for very small samples of plutonium. Resin beads were used to simulate particles; for samples ranging from 5--16 fg, collection efficiencies (ions collected per atom loaded) of 4--9% were obtained. Isotopic ratios with 4% precision and accuracy (240/239) were obtained.

Smith, D.H.; McKown, H.S.; Bostick, D.T.; Coleman, R.M.; Duckworth, D.C.; McPherson, R.L.

1994-01-01

448

Design-Only Conceptual Design Report: Plutonium Immobilization Plant  

SciTech Connect

This design-only conceptual design report was prepared to support a funding request by the Department of Energy Office of Fissile Materials Disposition for engineering and design of the Plutonium Immobilization Plant, which will be used to immobilize up to 50 tonnes of surplus plutonium. The siting for the Plutonium Immobilization Plant will be determined pursuant to the site-specific Surplus Plutonium Disposition Environmental Impact Statement in a Plutonium Deposition Record of Decision in early 1999. This document reflects a new facility using the preferred technology (ceramic immobilization using the can-in-canister approach) and the preferred site (at Savannah River). The Plutonium Immobilization Plant accepts plutonium from pit conversion and from non-pit sources and, through a ceramic immobilization process, converts the plutonium into mineral-like forms that are subsequently encapsulated within a large canister of high-level waste glass. The final immobilized product must make the plutonium as inherently unattractive and inaccessible for use in nuclear weapons as the plutonium in spent fuel from commercial reactors and must be suitable for geologic disposal. Plutonium immobilization at the Savannah River Site uses: (1) A new building, the Plutonium Immobilization Plant, which will convert non-pit surplus plutonium to an oxide form suitable for the immobilization process, immobilize plutonium in a titanate-based ceramic form, place cans of the plutonium-ceramic forms into magazines, and load the magazines into a canister; (2) The existing Defense Waste Processing Facility for the pouring of high-level waste glass into the canisters; and (3) The Actinide Packaging and Storage Facility to receive and store feed materials. The Plutonium Immobilization Plant uses existing Savannah River Site infra-structure for analytical laboratory services, waste handling, fire protection, training, and other support utilities and services. The Plutonium Immobilization Plant may share the disposition of the 50 tonnes of plutonium with the mixed oxide fuel/reactor disposition alternative. For this case, immobilization will process 18.2 tonnes of plutonium in 10 years.

DiSabatino, A.; Loftus, D.

1999-01-01

449

Aqueous Inorganic Sonochemistry  

NASA Astrophysics Data System (ADS)

This chapter discusses the effect of ultrasound propagation in water and aqueous solutions, in the atmosphere of inert and reactive gases. Sonochemical studies of aqueous solutions of divalent and trivalent metal ions and their salts have been reviewed and the precipitation behaviour of hydroxides of metal ions has been discussed. Synthesis of nanoparticles of many metals using ultrasound and in aqueous solutions has also been discussed briefly. Besides, the nephelometric and conductometric studies of sonicated solutions of these metal ions have been reported.

Pankaj

450

Crystal settling and in situ crystallization in aqueous solutions and magma chambers  

Microsoft Academic Search

Laboratory experiments are described in which aqueous solutions of potassium nitrate are cooled from above. Depending on the viscosity of the solution and the rate at which it is cooled, the mechanism of crystallization varies. In the least viscous, most slowly cooled experiment, after an initial period, crystals nucleate and grow on pre-existing crystals on the floor of the tank

Daniel Martin

1990-01-01

451

Validation of a modified spectrophotometric method for the determination of nitrate in dry milk using 2-sec-butylphenol.  

PubMed

A rapid, simple and direct visible spectrophotometric method, based on the quantitative nitration of 2-sec-butylphenol in concentrated sulfuric acid, is described for the determination of nitrate in milk. The nitration product was extracted into toluene and the yellow nitrophenoxide compound formed in alkaline aqueous solution was determined at 418 nm. Carrez reagents were used for protein precipitation. Interference from lactose, chloride and nitrite ions and the effect of reagent concentration was controlled. The calibration graph was linear over the range 0.5-5 micrograms ml-1 NO3-; y = -0.0019 + 0.0681 x; r = 0.9997. The limits of detection and quantification were found to be 0.18 and 0.5 microgram ml-1 NO3-, respectively. The accuracy of the method did not depend on nitrate content in spiked milk. The mean recovery of the spiked milk was found to be 99.81% with the confidence limits of 0.67%, a relative standard deviation (RSDr) of 1.79% for repeatability and an RSDR value of 1.90% for reproducibility. Adequate agreement was found between results obtained by the nitration method and those of the French official reduction spectrophotometric reference method (AFNor). For the Indonesian dry (powdered) milk sample studied the nitrate levels were in the range 10.7-29.5 mg kg-1 NO3-. PMID:7492033

Bintoro, V P; Cantin-Esnault, D; Alary, J

1995-11-01

452

Photodegradation of Paracetamol in Nitrate Solution  

SciTech Connect

The photodegradation of paracetamol in nitrate solution under simulated solar irradiation has been investigated. The degradation rates were compared by varying environmental parameters including concentrations of nitrate ion, humic substance and pH values. The quantifications of paracetamol were conducted by HPLC method. The results demonstrate that the photodegradation of paracetamol followed first-order kinetics. The photoproducts and intermediates of paracetamol in the presence of nitrate ions were identified by extensive GC-MS method. The photodegradation pathways involving. OH radicals as reactive species were proposed.

Meng Cui; Qu Ruijuan; Liang Jinyan; Yang Xi [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

2010-11-24

453

Nitric oxide, oxidants, and protein tyrosine nitration  

PubMed Central

The occurrence of protein tyrosine nitration under disease conditions is now firmly established and represents a shift from the signal transducing physiological actions of •NO to oxidative and potentially pathogenic pathways. Tyrosine nitration is mediated by reactive nitrogen species such as peroxynitrite anion (ONOO–) and nitrogen dioxide (•NO2), formed as secondary products of •NO metabolism in the presence of oxidants including superoxide radicals (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{O}}_{2}^{{\\bullet}-}\\end{equation*}\\end{document}), hydrogen peroxide (H2O2), and transition metal centers. The precise interplay between •NO and oxidants and the identification of the proximal intermediate(s) responsible for nitration in vivo have been under controversy. Despite the capacity of peroxynitrite to mediate tyrosine nitration in vitro, its role on nitration in vivo has been questioned, and alternative pathways, including the nitrite/H2O2/hemeperoxidase and transition metal-dependent mechanisms, have been proposed. A balanced analysis of existing evidence indicates that (i) different nitration pathways can contribute to tyrosine nitration in vivo, and (ii) most, if not all, nitration pathways involve free radical biochemistry with carbonate radicals (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{CO}}_{3}^{{\\bullet}-}\\end{equation*}\\end{document}) and/or oxo–metal complexes oxidizing tyrosine to tyrosyl radical followed by the diffusion-controlled reaction with •NO2 to yield 3-nitrotyrosine. Although protein tyrosine nitration is a low-yield process in vivo, 3-nitrotyrosine has been revealed as a relevant biomarker of •NO-dependent oxidative stress; additionally, site-specific nitration focused on particular protein tyrosines may result in modification of function and promote a biological effect. Tissue distribution and quantitation of protein 3-nitrotyrosine, recognition of the predominant nitration pathways and individual identification of nitrated proteins in disease states open new avenues for the understanding and treatment of human pathologies.

Radi, Rafael

2004-01-01

454

Transport of nitrates through clay using electrokinetics  

SciTech Connect

In this paper, the results of laboratory experiments to investigate the feasibility of using electrokinetics to transport nitrates (a nutrient) through a low-permeability soil are presented. Tests were conducted using a kaolinite soil consolidated from a slurry under a vertical stress of 127 kPa. Sodium nitrate was introduced in a chamber in front of a graphite electrode that becomes the cathode in the electrokinetic process. A hydraulic head was used to reduce the osmotic pressures. The results of the tests reveal that, under laboratory conditions, nitrates can be transported through low-permeability soils using electrokinetics.

Budhu, M.; Rasmussen, W. [Univ. of Arizona, Tucson, AZ (United States); Rutherford, M.; Sills, G. [Univ. of Oxford (United Kingdom)

1997-12-01

455

Extraction of lanthanide(III) nitrates with composite solid extractants based on a polymeric support impregnated with trialkylmethylammonium nitrate or TBP  

Microsoft Academic Search

Extraction of lanthanides(III) and Y(III) from 1–5 M aqueous NaNO3 with composite solid extractants based on a polymeric support impregnated with trialkylmethylammonium nitrate (Aliquat-336)\\u000a or TBP was studied, and the extraction constants were determined. The extraction isotherms were analyzed assuming that lanthanides\\u000a are extracted with the solid extractants in the form of complexes (R4N)2[Ln(NO3)5] and Ln(NO3)3(TBP)3.

A. K. Pyartman; V. V. Lishchuk; V. A. Keskinov

2006-01-01

456

PLUTONIUM CONTAMINATION VALENCE STATE DETERMINATION USING X-RAY ABSORPTION FINE STRUCTURE PERMITS CONCRETE RECYCLE  

SciTech Connect

This paper describes the determination of the speciation of plutonium contamination present on concrete surfaces at the Rocky Flats Environmental Technology Site (RFETS). At RFETS, the plutonium processing facilities have been contaminated during multiple events over their 50 year operating history. Contamination has resulted from plutonium fire smoke, plutonium fire fighting water, milling and lathe operation aerosols, furnace operations vapors and plutonium ''dust'' diffusion.

Ervin, P. F.; Conradson, S. D.

2002-02-25

457

A Note on the Reaction of Hydrogen and Plutonium  

SciTech Connect

Plutonium hydride has many practical and experimental purposes. The reaction of plutonium and hydrogen has interesting characteristics, which will be explored in the following analysis. Plutonium is a radioactive actinide metal that emits alpha particles. When plutonium metal is exposed to air, the plutonium oxides and hydrides, and the volume increases. PuH{sub 2} and Pu{sub 2}O{sub 3} are the products. Hydrogen is a catalyst for plutonium's corrosion in air. The reaction can take place at room temperature because it is fairly insensitive to temperature. Plutonium hydride, or PuH{sub 2}, is black and metallic. After PuH{sub 2} is formed, it quickly flakes off and burns. The reaction of hydrogen and plutonium is described as pyrophoric because the product will spontaneously ignite when oxygen is present. This tendency must be considered in the storage of metal plutonium. The reaction is characterized as reversible and nonstoichiometric. The reaction goes as such: Pu + H{sub 2} {yields} PuH{sub 2}. When PuH{sub 2} is formed, the hydrogen/plutonium ratio is between 2 and 2.75 (approximately). As more hydrogen is added to the system, the ratio increases. When the ratio exceeds 2.75, PuH{sub 3} begins to form along with PuH{sub 2}. Once the ratio surpasses 2.9, only PuH{sub 3} remains. The volume of the plutonium sample increases because of the added hydrogen and the change in crystal structure which the sample undergoes. As more hydrogen is added to a system of metal plutonium, the crystal structure evolves. Plutonium has a crystal structure classified as monoclinic. A monoclinic crystal structure appears to be a rectangular prism. When plutonium reacts with hydrogen, the product PuH{sub 2}, becomes a fluorite structure. It can also be described as a face centered cubic structure. PuH{sub 3} forms a hexagonal crystal structure. As plutonium evolves from metal plutonium to plutonium hydride to plutonium trihydride, the crystal structure evolves from monoclinic to fluorite to hexagonal. This change in crystal structure as a result of adding hydrogen is a shared characteristic with other actinide elements. Americium is isostructural with plutonium because they both form cubic dihyrides and hexagonal trihydrides. Reacting hydrogen with plutonium has the practical application of separating plutonium from other materials that don't react as well with hydrogen. When plutonium is placed in a chamber where there is very little oxygen, it can react with hydrogen without igniting. The hydrogen plutonium reaction can then be reversed, thus regaining the separated plutonium. Another application of this reaction is that it can be used to predict how plutonium reacts with other substances. Deuterium and tritium are two isotopes of hydrogen that are of interest. They are known to react likewise to hydrogen because they have similar properties. The reaction of plutonium and isotopes of hydrogen can prove to be very informative.

Noone, Bailey C [Los Alamos National Laboratory

2012-08-15

458

The effect of x rays, DTPA, and aspirin on the absorption of plutonium from the gastrointestinal tract of rats  

SciTech Connect

To measure the effect of radiation on plutonium transport, rats that were exposed to 250-kVp X rays were given /sup 238/Pu 3 days afterwards by either gavage or injection into a ligated segment of the duodenum. In a second group of experiments, rats were either injected intraduodenally with /sup 238/Pu-DTPA or administered the chelate intravenously and the /sup 238/Pu by gavage. In a third experiment, rats that had been gavaged with 200 or 400 mg/kg/day of aspirin for 2 days were injected intragastrically with /sup 238/Pu nitrate. Results of the first experiment showed a dose-dependent increase in /sup 238/Pu absorption between 800 and 1500 rad of lower-body X irradiation. Intravenous or intraduodenal injections of DTPA caused a marked increase in /sup 238/Pu absorption but resulted in decreased plutonium deposition in the skeleton and liver. Retention of /sup 238/Pu in the skeleton of rats given aspirin was double that of controls, but the effect on plutonium absorption was less marked than that of DTPA.

Sullivan, M.F.; Gorham, L.S.; Miller, B.M.

1983-04-01

459

Ultraviolet irradiation effects incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter  

USGS Publications Warehouse

One of the concerns regarding the safety and efficacy of ultraviolet radiation for treatment of drinking water and wastewater is the fate of nitrate, particularly its photolysis to nitrite. In this study, 15N NMR was used to establish for the first time that UV irradiation effects the incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter (NOM). Irradiation of 15N-labeled nitrate in aqueous solution with an unfiltered medium pressure mercury lamp resulted in the incorporation of nitrogen into Suwannee River NOM (SRNOM) via nitrosation and other reactions over a range of pH from approximately 3.2 to 8.0, both in the presence and absence of bicarbonate, confirming photonitrosation of the NOM. The major forms of the incorporated label include nitrosophenol, oxime/nitro, pyridine, nitrile, and amide nitrogens. Natural organic matter also catalyzed the reduction of nitrate to ammonia on irradiation. The nitrosophenol and oxime/nitro nitrogens were found to be susceptible to photodegradation on further irradiation when nitrate was removed from the system. At pH 7.5, unfiltered irradiation resulted in the incorporation of 15N-labeled nitrite into SRNOM in the form of amide, nitrile, and pyridine nitrogen. In the presence of bicarbonate at pH 7.4, Pyrex filtered (cutoff below 290–300 nm) irradiation also effected incorporation of nitrite into SRNOM as amide nitrogen. We speculate that nitrosation of NOM from the UV irradiation of nitrate also leads to production of nitrogen gas and nitrous oxide, a process that may be termed photo-chemodenitrification. Irradiation of SRNOM alone resulted in transformation or loss of naturally abundant heterocyclic nitrogens.

Thorn, Kevin A.; Cox, Larry G.

2012-01-01

460

X-ray and neutron diffraction studies on concentrated aqueous solutions of sodium nitrate and silver nitrate  

Microsoft Academic Search

Neutron diffraction experiments have been conducted on 3.1 M (molar) solutions of 107AgNO3 and 109AgNO3 in heavy water, and the first-order difference method of isotopic substitution has been used to obtain the local structure around Ag(aq)+. The results of this work have been used in conjunction with those from an X-ray diffraction study of 3.1 M (molar) AgNO3 and NaNO3,

N. T. Skipper; G. W. Neilson

1989-01-01

461

High-pressure sound velocity and equation of state of aqueous solutions of hydroxylammonium nitrate and triethanolammonium nitrate  

Microsoft Academic Search

A cell for high pressure sound velocity measurements of liquids was designed and used in a Birch-Bridgman high pressure system with a liquid propellant specimen. The dependence of the sound velocity on pressure to 4.2 kbar (4200 atmospheres) was measured at room temperature and on temperature between 220 and 293 K at room pressure. These data, together with the temperature

J. Frankel; M. Doxbeck

1987-01-01

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