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1

Separation of thorium impurity from plutonium in the nitrate anion exchange process  

SciTech Connect

Thorium is a common impurity in many materials processed at the Los Alamos Plutonium Facility. Although the thorium impurity level is usually less than 1000 ppM, it frequently exceeds the maximum allowable limit of 100 ppM. Thorium is especially difficult to separate from plutonium because it accompanies plutonium in the three aqueous nitrate processes used at Los Alamos: nitrate anion exchange, oxalate precipitation, and peroxide precipitation. Nitrate anion exchange, the major aqueous plutonium purification process, has recently been modified to remove most of the thorium from sorbed plutonium by washing the column with 4.7 M nitric acid-0.007 M hydrofluoric acid. This chromatographic washing technique requires careful process control that is readily attainable with the recently developed Los Alamos On-Line Gamma Monitor. The successful separation of thorium using this modification has been demonstrated in routine, full-scale, nitrate anion exchange operations. 3 refs., 8 figs.

Marsh, S.F.; Phillips, B.J.; Aldaz, E.A.; Williams, W.E.

1989-04-01

2

EXTRACTION OF URANYL NITRATE FROM AQUEOUS SOLUTIONS  

DOEpatents

An improvement in the process is described for extracting aqueous uranyl nitrate solutions with an organic solvent such as ether. It has been found that the organic phase will extract a larger quantity of uranyl nitrate if the aqueous phase contains in addition to the uranyl nitrate, a quantity of some other soluble nitrate to act as a salting out agent. Mentioned as suitable are the nitrates of lithium, calcium, zinc, bivalent copper, and trivalent iron.

Furman, N.H.; Mundy, R.J.

1957-12-10

3

RECOVERY OF PLUTONIUM FROM AQUEOUS SOLUTIONS  

DOEpatents

A process is described for recovering plutonium values from aqueous solutions by precipitation on bismuth phosphate. The plutonium is secured in its tetravalent state. bismuth salt is added to the solution, and ant excess of phosphoric acid anions is added to the solution in two approximately equal installments. The rate of addition of the first installment is about two to three times as high as the rate of addition of the second installment, whereby a precipitate of bismuth phosphate forms, the precipitate carrying the plutonium values. The precipitate is separated from the solution.

Reber, E.J.

1959-09-01

4

METHOD OF RECOVERING PLUTONIUM VALUES FROM AQUEOUS SOLUTIONS BY CARRIER PRECIPITATION  

DOEpatents

A process is presented for pretreating aqueous nitric acid- plutonium solutions containing a small quantity of hydrazine that has formed as a decomposition product during the dissolution of neutron-bombarded uranium in nitric acid and that impairs the precipitation of plutonium on bismuth phosphate. The solution is digested with alkali metal dichromate or potassium permanganate at between 75 and 100 deg C; sulfuric acid at approximately 75 deg C and sodium nitrate, oxaiic acid plus manganous nitrate, or hydroxylamine are added to the solution to secure the plutonium in the tetravalent state and make it suitable for precipitation on BiPO/sub 4/.

James, R.A.; Thompson, S.G.

1959-11-01

5

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

6

The photochemistry of aqueous nitrate ion revisited  

Microsoft Academic Search

Aqueous nitrate solutions were photolysed at 254 nm in the absence of oxidizable additives, in the presence of methanol or propan-2-ol and oxygen and in the presence of cyclopentane under anaerobic conditions. The main nitrogen-containing products are nitrite and peroxynitrite. The quantum yields depend on the pH, nitrate concentration, nature of the additive and the light intensity. The intrinsic nitrite

Gertraud Mark; Hans-Gert Korth; Heinz-Peter Schuchmann; Clemens von Sonntag

1996-01-01

7

Solubility of plutonium nitrate in uranyl nitrate hexahydrate melt  

Microsoft Academic Search

At a weight fraction below 20%, Pu(IV) nitrate is isomorphically dissolved and homogeneously distributed in the uranyl nitrate\\u000a hexahydrate phase, the solubility being independent of the HNO3 concentration in the mixed U-Pu melt up to the acid concentration of 7 M. In dissolving solid Pu(IV) nitrate in 1–6 M HNO3, Pu(IV) disproportionates to form Pu(III) and Pu(VI). With increasing HNO3

Yu. M. Kulyako; T. I. Trofimov; M. D. Samsonov; A. Yu. Shadrin; B. F. Myasoedov

2008-01-01

8

Process for decomposing nitrates in aqueous solution  

DOEpatents

This invention is a process for decomposing ammonium nitrate and/or selected metal nitrates in an aqueous solution at an elevated temperature and pressure. Where the compound to be decomposed is a metal nitrate (e.g., a nuclear-fuel metal nitrate), a hydroxylated organic reducing agent therefor is provided in the solution. In accordance with the invention, an effective proportion of both nitromethane and nitric acid is incorporated in the solution to accelerate decomposition of the ammonium nitrate and/or selected metal nitrate. As a result, decomposition can be effected at significantly lower temperatures and pressures, permitting the use of system components composed of off-the-shelf materials, such as stainless steel, rather than more costly materials of construction. Preferably, the process is conducted on a continuous basis. Fluid can be automatically vented from the reaction zone as required to maintain the operating temperature at a moderate value--e.g., at a value in the range of from about 130.degree.-200.degree. C.

Haas, Paul A. (Knoxville, TN)

1980-01-01

9

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

10

SEPARATION OF PLUTONIUM FROM AQUEOUS SOLUTIONS BY ION-EXCHANGE  

DOEpatents

A process is described for the separation of plutonium from an aqueous solution of a plutonium salt, which comprises adding to the solution an acid of the group consisting of sulfuric acid, phosphoric acid, and oxalic acid, and mixtures thereof to provide an acid concentration between 0.0001 and 1 M, contacting the resultant solution with a synthetic organic anion exchange resin, and separating the aqueous phase and the resin which contains the plutonium.

Schubert, J.

1958-06-01

11

Influence of Acidity on Uranyl Nitrate Association in Aqueous Solutions: A Molecular Dynamics Simulation Study  

SciTech Connect

Uranyl ion complexation with water and nitrate is a key aspect of the uranium/plutonium extraction process. We have carried out a molecular dynamics simulation study to investigate this complexation process, including the molecular composition of the various complex species, the corresponding structure, and the equilibrium distribution of the complexes. The observed structures of the complexes suggest that in aqueous solution, uranyls are generally hydrated by 5 water molecules in the equatorial plane. When associating with nitrate ions, a water molecule is replaced by a nitrate ion, preserving the five-fold coordination and planar symmetry. Analysis of the pair correlation function between uranyl and nitrate suggests that nitrates bind to uranyl in aqueous solution mainly in a monodentate mode, although a small portion of bidentates occur. Dynamic association and dissociation between uranyls and nitrates take place in aqueous solution with a substantial amount of fluctuation in the number of various uranyl nitrate species. The average number of the uranyl mononitrate complexes shows a dependence on acid concentration consistent with equilibrium-constant analysis, namely, the concentration of [UO2NO3]+ increases with nitric acid concentration.

de Almeida, Valmor F [ORNL; Cui, Shengting [ORNL; Khomami, Bamin [ORNL; Ye, Xianggui [ORNL; Smith, Rodney Bryan [ORNL

2010-01-01

12

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

13

Nitrate anion templated assembly of a [2]rotaxane for selective nitrate recognition in aqueous solvent mixtures.  

PubMed

The first nitrate anion templated assembly of an interlocked molecular architecture is demonstrated through the preparation of a [2]rotaxane. Removal of the discrete nitrate anion template from the [2]rotaxane reveals an interlocked host system capable of strong and selective recognition of nitrate, in aqueous-organic solvent mixtures, over a range of more basic mono-charged oxoanions. PMID:23949001

Langton, Matthew J; Duckworth, Lucy C; Beer, Paul D

2013-10-01

14

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

15

Summary of the Risk Assessment Made of the Transport of Plutonium Nitrate.  

National Technical Information Service (NTIS)

A detailed risk assessment of the transport of plutonium nitrate that was made by members of the staff of the Safety and Reliability Directorate is summarised. The study examines the criteria of acceptable risk, and gives an assessment of the individual a...

J. C. Chicken

1980-01-01

16

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

17

Criticality experiments with mixed plutonium and uranium nitrate solution at a plutonium fraction of 0.4 in slab geometry  

SciTech Connect

R. C. Lloyd of PNL has completed and published a series of critical experiments with mixed plutonium- uranium nitrate solutions (Reference 1). This series of critical experiments was part of an extensive program jointly sponsored by the U. S. Department of Energy (DOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan and was carried out in the mid-1980`s. The experiments evaluated here (published as Report PNL-6327) were performed with mixed plutonium- uranium nitrate solution in a variable thickness slab tank with two 106.7 cm square sides and a width that could be varied from 7.6 to 22.8 cm. The objective of these experiments was to obtain experimental data to permit the validation of computer codes for criticality calculations and of cross-section data to minimize the uncertainties inherent therein, so that facility safety, efficiency, and reliability could be enhanced. The concentrations of the solution were about 105, 293, and 435 g(Pu+U)/liter with a ratio of plutonium to total heavy metal (plutonium plus uranium) of about 0. 40 for all eight experiments. Four measurements were made with a water reflector, and four with no reflector. Following the publication of the initial PNL reports, considerable effort was devoted to an extensive reevaluation of this series of experiments by a collaboration of researchers from ORNL, PNL, and PNC (Reference 2). Their work resulted in a more accurate description of the ``as built`` hardware configuration and the materials specifications. For the evaluations in this report, the data published in Reference 2 by Smolen et al. is selected to supersede the original PNL report. Eight experiments have been evaluated and seven (063, 064, 071, 072, 074, 075, and 076) provide benchmark criticality data. Experiment 073 could not achieve criticality within vessel height limitations.

Pohl, B.A.; Keeton, S.C.

1997-09-01

18

Basis document for PFP plutonium nitrate ion exchange process in Room 228A  

SciTech Connect

The PFP facility currently has approximately 4300 liters of plutonium nitrate solution in storage. This material will be calcined by the Vertical Denigration Calciner (VDC) located in room 230C. However, part of the material needs to be purified to remove constituents that will interfere with the calcination process. An Ion Exchange process using Reillex{trademark} HPQ anion exchange resin was tested by the Plutonium Process Support Laboratories (PPSL) (I). The Ion exchange process is to be installed in glovebox HC-7 in room 228A/234-5Z. The plutonium separated from the interfering constituents will be in a concentrated condition ready to be calcined by the VDC in room 230C. The oxide product of the VDC will be placed into the 2736-Z vaults for long term storage.

Risenmay, H.R.

1997-04-23

19

Aqueous Recovery of Plutonium from Pyrochemical Processing Residues.  

National Technical Information Service (NTIS)

Pyrochemical processes provide rapid methods to reclaim plutonium from scrap residues. Frequently, however, these processes yield an impure plutonium product and waste residues that are contaminated with actinides and are therefore nondiscardable. The Sav...

L. W. Gray J. H. Gray

1984-01-01

20

Plutonium  

MedlinePLUS

... to Plutonium How does plutonium get into the environment? Plutonium was dispersed world wide from atmospheric testing ... of page How does plutonium change in the environment? All isotopes of plutonium undergo radioactive decay. As ...

21

Criticality experiments with a mixed-oxide fuel pin array in plutonium-uranium nitrate solutions  

SciTech Connect

A series of critical experiments was completed with an array of mixed-oxide (MOX) fuel pins surrounded by plutonium-uranium nitrate solutions. The experiments were performed under a joint Criticality Data Development Program between the US Department of Energy and the Power Reactor and Nuclear Fuel development Corporation of Japan. The critical experiments were performed in the Critical Mass Laboratory (CML) of the Pacific Northwest Laboratory (PNL). The objectives of these experiments are to provide criticality data for a heterogeneous system of fuel pins moderated with plutonium-uranium and to determine the effectiveness of soluble gadolinium as a neutron absorber for criticality control in optimizing the physical size of equipment. Experiments have been performed in a similar configuration; however, these new experiments provide criticality data for a tighter fuel lump spacing, where soluble neutron poisons are not as effective.

Lloyd, R.C.; Smolen, G.R.; Matsumoto, T.

1989-01-01

22

Plutonium-uranium separation in the Purex process using mixtures of hydroxylamine nitrate and ferrous sulfamate  

SciTech Connect

Laboratory studies, followed by plant operation, established that a mixture of hydroxylamine nitrate (HAN) and ferrous sulfamate (FS) is superior to FS used alone as a reductant for plutonium in the Purex first cycle. FS usage has been reduced by about 70% (from 0.12 to 0.04M) compared to the pre-1978 period. This reduced the volume of neutralized waste due to FS by 194 liters/metric ton of uranium (MTU) processed. The new flowsheet also gives lower plutonium losses to waste and at least comparable fission product decontamination. To achieve satisfactory performance at this low concentration of FS, the acidity in the 1B mixer-settler was reduced by using a split-scrub - a low acid scrub in stage one and a higher acid scrub in stage three - to remove acid from the solvent exiting the 1A centrifugal contactor. 8 references, 14 figures, 1 table.

McKibben, J.M.; Chostner, D.F.; Orebaugh, E.G.

1983-11-01

23

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

24

Extraction of uranyl nitrate from concentrated aqueous salt solutions by tributyl phosphate  

SciTech Connect

Equations have been proposed for describing isotherms of extraction of uranyl nitrate from concentrated aqueous salt solutions by neat tri-n-butyl phosphate, with account taken of variations of activity coefficients of the components in organic phase over a wide range of its compositions. The constants of extraction equilibria, calculated for a standard hypothetical 1 M aqueous solution of uranyl nitrate and the state of pure components in organic phase with a mole fraction of 1, have been determined assuming formation of uranyl nitrate disolvate and trisolvate in the organic phase. The excessive thermodynamic functions of mixing tri-n-butyl phosphate with uranyl nitrate disolvate are presented.

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

1995-01-01

25

Criticality experiments with mixed oxide fuel pin arrays in plutonium-uranium nitrate solution  

SciTech Connect

A series of critical experiments was completed with mixed plutonium-uranium solutions having a Pu/(Pu + U) ratio of approximately 0.22 in a boiler tube-type lattice assembly. These experiments were conducted as 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 the experiments and data are included in this report. The experiments were performed with an array of mixed oxide fuel pins in aqueous plutonium-uranium solutions. The fuel pins were contained in a boiler tube-type tank and arranged in a 1.4 cm square pitch array which resembled cylindrical geometry. One experiment was perfomed with the fuel pins removed from the vessel. The experiments were performed with a water reflector. The concentration of the solutions in the boiler tube-type tank was varied from 4 to 468 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was approximately 0.22 for all experiments.

Lloyd, R.C. (Pacific Northwest Lab., Richland, WA (United States)); Smolen, G.R. (Oak Ridge National Lab., TN (United States))

1988-08-01

26

Effects of inhaled plutonium nitrate on bone and liver in dogs  

SciTech Connect

The life-span biological effects of inhaled soluble, alpha-emitting radionuclides deposited in the skeleton and liver were studied in 5 groups of 20 beagles exposed to initial lung depositions ranging from 0.48 to 518 Bq/g of lung. Average plutonium amounts in the lungs decreased to approximately 1% of the final body deposition in dogs surviving 5 years or more; more than 90% of the final depositions accumulated in the liver and skeleton. The liver-to-skeletal ratio of deposited plutonium was 0.83. The incidence of bone tumors, primarily osteogenic sarcomas causing early mortality, at final group average skeletal depositions of 15.8, 2.1, and 0.5 Bq/g was, respectively, 85%, 50%, and 5%; there were no bone tumors in exposure groups with mean average depositions lower than 0.5 Bq/g. Elevated serum liver enzyme levels were observed in exposure groups down to 1.3 Bq/g. The incidence of liver tumors at final group average liver depositions of 6.9, 1.3, 0.2, and 0.1 Bq/g, was, respectively, 25%, 15%, 15%, and 15%; one hepatoma occurred among 40 control dogs. The risk of the liver cancer produced by inhaled plutonium nitrate was difficult to assess due to the competing risks of life shortening from lung and bone tumors.

Dagle, G.E.; Weller, R.E.; Watson, C.R.; Buschbom, R.L. [Pacific Northwest Lab., Richland, WA (United States). Biology and Chemistry Dept.

1994-04-01

27

Vapor-liquid equilibria for nitric acid-water and plutonium nitrate-nitric acid-water solutions  

Microsoft Academic Search

The liquid-vapor equilibrium data for nitric acid and nitric acid-plutnonium nitrate-water solutions were examined to develop correlations covering the range of conditions encountered in nuclear fuel reprocessing. The scanty available data for plutonium nitrate solutions are of poor quality but allow an order of magnitude estimate to be made. A formal thermodynamic analysis was attempted initially but was not successful

Maimoni

1980-01-01

28

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

29

Kinetics of some aqueous-phase reactions of peroxyacetyl nitrate  

SciTech Connect

The contribution to cloudwater acidification by reactions of peroxyacetyl nitrate (PAN) with various atmospheric species reported in this work. Clearly, at representative concentration of PAN (less than or equal to 5 x 10/sup -9/ atm), the reactions which have been studied here are not fast enough to contribute significantly to acid formation in the cloudwater. One exception might be the reaction between PAN and S(IV) at higher pH (greater than or equal to 5.6) although few cloud or rain samples collected have shown pH values higher than this value. It was also noted that PAN does not produce H/sub 2/O/sub 2/ from its hydrolysis and aqueous reactions with O/sub 2/ and O/sub 3/. Based on this study it is concluded that in spite of its greater solubility, PAN is not an important precursor of acid or oxidant for the cloudwater and its atmospheric residence time is not affected by wet removal processes; these properties would enhance the importance of this species as a long-range transporting reagent of NO/sub x/. 16 references, 7 figures.

Lee, Y.N.

1984-04-01

30

Thermodynamic quantities of surface formation of aqueous electrolyte solutions VII. Aqueous solution of alkali metal nitrates LiNO3, NaNO3, and KNO3.  

PubMed

To compare the effect of nitrate anions on the surface tension increments of aqueous solutions with that of halide anions, the surface tension of aqueous solutions of lithium nitrate, sodium nitrate, and potassium nitrate was measured as a function of temperature and concentration. It is shown that the surface tension of aqueous alkali metal nitrate solutions is determined primarily by the kinds of anions, since the surface tension increments of these nitrates were of the same magnitude. The importance of the electrical double layer at the surface is discussed in relation to these surface tension increments. PMID:17707855

Matubayasi, Norihiro; Yoshikawa, Ryuji

2007-08-20

31

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

32

Reillex/trademark/ HPQ: A new, macroporous polyvinylpyridine resin for separating plutonium using nitrate anion exchange  

SciTech Connect

Anion exchange in nitric acid is the major aqueous process used to recover and purify plutonium from impure scrap materials. Most strong-base anion exchange resins incorporate a styrene-divinylbenzene copolymer. A newly available, macroporous anion exchange resin based on a copolymer of 1-methyl-4-vinylpyridine and divinylbenzene has been evaluated. Comparative data for Pu(IV) sorption kinetics and capacity are presented for this new resin and two other commonly used anion exchange resins. The new resin offers high capacity and rapid sorption kinetics for Pu(IV) from nitric acid, as well as greater stability to chemical and radiolytic degradation. 8 refs., 12 figs.

Marsh, S.F.

1989-01-01

33

Evaluation of a new, macroporous polyvinylpyridine resin for processing plutonium using nitrate anion exchange  

SciTech Connect

Anion exchange in nitric acid is the major aqueous process used to recover and purify plutonium from impure scrap materials. Most strong-base anion exchange resins incorporate a styrene-divinylbenzene copolymer. A newly available, macroporous anion exchange resin based on a copolymer of 1-methyl-4-vinylpyridine and divinylbenzene has been evaluated. Comparative data for Pu(IV) sorption kinetics and capacity are presented for this new resin and two other commonly used anion exchange resins. The new resin offers high capacity and rapid sorption kinetics for Pu(IV) from nitric acid, as well as greatly stability to chemical and radiolytic degradation. 8 refs., 14 figs.

Marsh, S.F.

1989-04-01

34

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

35

Recovery of Plutonium(IV) from Aqueous Solutions Using Emulsion Liquid Membrane Containing 2?Ethylhexyl Phosphonic Acid Mono?2?Ethylhexyl Ester as Ion Transporter  

Microsoft Academic Search

An emulsion liquid membranes (ELMs) containing 2?ethylhexyl phosphonic acid mono?2?ethylhexyl ester (H2A2) was tested for the extraction of plutonium(IV) from aqueous nitrate solutions of different compositions. Span 80 was used as the surface?active agent and a mixture of 0.05 mol dm HNO3+0.3 mol dm H2C2O4 was used as the internal phase. Influence of some important experimental parameters such as exterior phase nitric acid concentration,

C. S. Kedari; S. S. Pandit; S. D. Chowta; U. Jambunathan

2005-01-01

36

Kinetics of Some Aqueous-Phase Reactions of Peroxyacetyl Nitrate.  

National Technical Information Service (NTIS)

The contribution to cloudwater acidification by reactions of peroxyacetyl nitrate (PAN) with various atmospheric species reported in this work. Clearly, at representative concentration of PAN (less than or equal to 5 x 10 exp -9 atm), the reactions which ...

Y. N. Lee

1984-01-01

37

CONCENTRATION AND DECONTAMINATION OF SOLUTIONS CONTAINING PLUTONIUM VALUES BY BISMUTH PHOSPHATE CARRIER PRECIPITATION METHODS  

Microsoft Academic Search

A process is given for isolating plutonium present in the tetravalent ; state in an aqueous solution together with fission products. First, the ; plutonium and fission products are coprecipitated on a bismuth phosphate carrier. ; The precipitate obtained is dissolved, and the plutonium in the solution is ; oxidized to the hexavalent state (with ceric nitrate, potassium dichromate, Pb\\/;

G. T. Seaborg; S. G. Thompson

1960-01-01

38

Speciation model selection by Monte Carlo analysis of optical absorption spectra: Plutonium(IV) nitrate complexes  

SciTech Connect

Standard modeling approaches can produce the most likely values of the formation constants of metal-ligand complexes if a particular set of species containing the metal ion is known or assumed to exist in solution equilibrium with complexing ligands. Identifying the most likely set of species when more than one set is plausible is a more difficult problem to address quantitatively. A Monte Carlo method of data analysis is described that measures the relative abilities of different speciation models to fit optical spectra of open-shell actinide ions. The best model(s) can be identified from among a larger group of models initially judged to be plausible. The method is demonstrated by analyzing the absorption spectra of aqueous Pu(IV) titrated with nitrate ion at constant 2 molal ionic strength in aqueous perchloric acid. The best speciation model supported by the data is shown to include three Pu(IV) species with nitrate coordination numbers 0, 1, and 2. Formation constants are {beta}{sub 1}=3.2{+-}0.5 and {beta}{sub 2}=11.2{+-}1.2, where the uncertainties are 95% confidence limits estimated by propagating raw data uncertainties using Monte Carlo methods. Principal component analysis independently indicates three Pu(IV) complexes in equilibrium. (c) 2000 Society for Applied Spectroscopy.

Berg, John M. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Veirs, D. Kirk [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Vaughn, Randolph B. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Cisneros, Michael R. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Smith, Coleman A. [Nuclear Materials Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2000-06-01

39

Nitrate Anion Exchange in Pu-238 Aqueous Scrap Recovery Operations  

SciTech Connect

Strong base, nitrate anion exchange (IX) is crucial to the purification of {sup 238}Pu solution feedstocks with gross levels of impurities. This paper discusses the work involved in bench scale experiments to optimize the nitrate anion exchange process. In particular, results are presented of experiments conducted to (a) demonstrate that high levels of impurities can be separated from {sup 238}Pu solutions via nitrate anion exchange and, (b) work out chemical pretreatment methodology to adjust and maintain {sup 238}Pu in the IV oxidation state to optimize the Pu(IV)-hexanitrato anionic complex sorption to Reillex-HPQ resin. Additional experiments performed to determine the best chemical treatment methodology to enhance recovery of sorbed Pu from the resin, and VIS-NIR absorption studies to determine the steady state equilibrium of Pu(IV), Pu(III), and Pu(VI) in nitric acid are discussed.

Pansoy-Hjelvik, M.E.; Silver, G.L.; Reimus, M.A.H.; Ramsey, K.B.

1999-01-31

40

Extraction of nitric acid, uranyl nitrate, and bismuth nitrate from aqueous nitric acid solutions with CMPO  

SciTech Connect

DOE sponsored development of the transuranium extraction (TRUEX) process for removing actinides from radioactive wastes. The solvent is a mixture of CMPO and TBP. Since the extraction characteristics of CMPO are not as well understood as those of TBP, the extraction of nitric acid, uranyl nitrate, and bismuth nitrate with CMPO (dissolved in n-dodecane) were studied. Results indicate that CMPO extracts nitric acid with a 1:1 stoichiometry; equilibrium constant is 2. 660{plus_minus}0.092 at 25 C, and extraction enthalpy is -5. 46{plus_minus}0.46 kcal/mol. Slope analysis indicates that uranyl nitrate extracts with a mixed equilibria of 1:1 and 2:1 stoichiometries in nearly equal proportion. Equil. constant of the 2: 1 extraction was 1.213 {times} 10{sup 6}{plus_minus}3.56 {times} 10{sup 4} at 25 C; reaction enthalpy was -9.610{plus_minus}0.594 kcal/mol. Nitration complexation constant is 8.412{plus_minus}0.579, with an enthalpy of -10.72{plus_minus}1.87 kcal/mol. Bismuth nitrate also extracts with a mixed equilibria of (perhaps) 1:1 and 2:1 stoichiometries. A 2:1 extraction equilibrium and a nitrate complexation adequately model the data. Kinetics and enthalpies were also measured.

Spencer, B.B.

1995-08-01

41

Photochemistry of nitrite and nitrate in aqueous solution: a review  

Microsoft Academic Search

It has long been known that the photolysis of nitrite and nitrate solutions results in the formation of OH radicals. The mechanism of NO3? photolysis has been the subject of considerable controversy in the literature, however. This review summarizes the experimental work on NO2? and NO3? photolysis in the context of recent advances in the understanding of the chemistry of

John Mack; James R. Bolton

1999-01-01

42

ROLE OF DISSOLVED ORGANIC MATTER, NITRATE, AND BICARBONATE IN THE PHOTOLYSIS OF AQUEOUS FIPRONIL  

Technology Transfer Automated Retrieval System (TEKTRAN)

A multivariate kinetic model of the photodegradation of aqueous fipronil was developed as a function of dissolved organic matter (DOM), bicarbonate, and nitrate at concentrations that bracket those commonly observed in natural waters (ca. 0-10 mg/L). Several pathways were available for fipronil pho...

43

Plutonium  

Microsoft Academic Search

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

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

2011-01-01

44

Plutonium  

Microsoft Academic Search

\\u000a The element plutonium occupies a unique place in the history of chemistry, physics, technology, and international relations.\\u000a After the initial discovery based on submicrogram amounts, it is now generated by transmutation of uranium in nuclear reactors\\u000a on a large scale, and has been separated in ton quantities in large industrial facilities. The intense interest in plutonium\\u000a resulted fromthe dual-use scenario

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

45

Plutonium  

Microsoft Academic Search

The element plutonium occupies a unique place in the history of chemistry, physics, technology, and international relations.\\u000a After the initial discovery based on submicrogram amounts, it is now generated by transmutation of uranium in nuclear reactors\\u000a on a large scale, and has been separated in ton quantities in large industrial facilities. The intense interest in plutonium\\u000a resulted from the dual-use

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

46

Performance of immobilized Saccharomyces cerevisiae in the removal of long lived radionuclides from aqueous nitrate solutions  

Microsoft Academic Search

The efficiency of tailor made immobilized Saccharomyces\\u000acerevisiae(biomatrix) for the sorption of radionuclides 233U, 239Pu, 241Am, 137Ce, 144Cs, 103,106Ru and 90Sr from aqueous nitrate solutions at different pH was studied. Effect of ionic strength, anionic components, initial metal concentration and particle size of the biomatrix on the sorption of metal ions were investigated. At pH in the range of 1

S. K. Das; C. S. Kedari; S. S. Shinde; S. Ghosh; U. Jambunathan

2002-01-01

47

Criticality experiments with planar arrays of three-liter bottles containing plutonium nitrate solution  

SciTech Connect

The objective of these experiments was to provide benchmark data to validate calculational codes used in critically safety assessments of plant configurations. Arrays containing up to as many as sixteen three-liter bottles filled with plutonium nitrate were used in the experiments. A split-table device was used in the final assembly of the arrays. Ths planar arrays were reflected with close fitting plexiglas on each side and on the bottom but not the top surface. The experiments addressed a number of factors effecting criticality: the critical air gap between bottles in an array of fixed number of bottles, the number of bottles required for criticality if the bottles were touching, and the effect on critical array spacing and critical bottle number due to the insertion of an hydrogeneous substance into the air gap between bottles. Each bottle contained about 2.4l of Pu(NO{sub 3}){sub 4} solution at a Pu concentration of 105g Pu/l, with the {sup 240}Pu content being 2.9 wt% at a free acid molarity H{sup +} of 5.1. After the initial series of experiments were performed with bottles separated by air gaps, plexiglas shells of varying thicknesses were placed around each bottle to investigate how moderation between bottles affects both the number of bottles required for criticality and the critical spacing between each bottle. The minimum of bottles required for criticality was found to be 10.9 bottles, occurring for a square array with bottles in contact. As the bottles were spaced apart, the critical number increased. For sixteen bottles in a square array, the critical separation between surfaces in both x and y direction was 0.96 cm. The addition of plexiglas around each bottle decreased the critical bottle number, compared to those separated in air, but the critical bottle number, even with interstitial plastic in place was always greater than 10.9 bottles. The most reactive configuration was a tightly packed array of bottles with no intervening material.

Durst, B.M.; Clayton, E.D.; Smith, J.H.

1985-01-01

48

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

49

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.

50

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

2013-06-11

51

Chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions  

SciTech Connect

These analytical procedures are designed to show whether a given material meets the purchaser's specifications as to plutonium content, effective fissile content, and impurity content. The following procedures are described in detail: plutonium by controlled-potential coulometry; plutonium by amperometric titration with iron(II); free acid by titration in an oxalate solution; free acid by iodate precipitation-potentiometric titration method; uranium by Arsenazo I spectrophotometric method; thorium by thorin spectrophotometric method; iron by 1,10-phenanthroline spectrophotometric method; chloride by thiocyanate spectrophotometric method; fluoride by distillation-spectrophotometric method; sulfate by barium sulfate turbidimetric method; isotopic composition by mass spectrometry; americium-241 by extraction and gamma counting; americium-241 by gamma counting; gamma-emitting fission products, uranium, and thorium by gamma-ray spectroscopy; rare earths by copper spark spectrochemical method; tungsten, niobium (columbium), and tantalum by spectrochemical method; simple preparation by spectrographic analysis for general impurities. (JMT)

Not Available

1981-01-01

52

The effect of temperature on the complexation of Cm(III) with nitrate in aqueous solutions.  

PubMed

The complexation of curium(III) with nitrate was studied at different temperatures (10-85 °C) by luminescence spectroscopy. The stability constants of CmNO(3)(2+) were calculated from the luminescence emission spectra. The specific ion interaction approach (SIT) was used to obtain the stability constants of CmNO(3)(2+) at infinite dilution and variable temperatures. The complexation is weak and little effect of temperature on the complexation was observed over the temperature range 10-85 °C. Data on the luminescence lifetime indicate that each nitrate ligand replaces two water molecules from the inner coordination sphere of Cm(3+), forming a bidentate inner-sphere complex with Cm(3+) in aqueous solutions. PMID:21135933

Rao, Linfeng; Tian, Guoxin

2010-12-06

53

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

54

Glancing-angle Raman study of nitrate and nitric acid at the air-aqueous interface  

NASA Astrophysics Data System (ADS)

Glancing-angle Raman spectra of aqueous KNO3 and HNO3 solutions were used to determine the degree of nitric acid dissociation, ?, in the bulk and in the surface region. Our results suggest that ? in the surface region is similar to that in the bulk and highlight the importance of water molecule availability to the dissociation process. Using the ?'s and the ?-symNO3- Raman intensities, we obtained an adsorption isotherm for NO3- to the surface region from which we calculated a Kads, of 0.19 ± 0.03 L mol-1, implying that nitrate exhibits an almost neutral surface affinity.

Wren, Sumi N.; Donaldson, D. J.

2012-01-01

55

Effects of inhaled plutonium nitrate on bone and liver in dogs.  

National Technical Information Service (NTIS)

The life-span biological effects of inhaled soluble, alpha-emitting radionuclides deposited in the skeleton and liver were studied in 5 groups of 20 beagles exposed to initial lung depositions ranging from 0.48 to 518 Bq/g of lung. Average plutonium amoun...

C. R. Watson G. E. Dagle R. E. Weller R. L. Buschbom

1994-01-01

56

Separation of Thorium Impurity from Plutonium in the Nitrate Anion Exchange Process.  

National Technical Information Service (NTIS)

Thorium is a common impurity in many materials processed at the Los Alamos Plutonium Facility. Although the thorium impurity level is usually less than 1000 ppM, it frequently exceeds the maximum allowable limit of 100 ppM. Thorium is especially difficult...

S. F. Marsh B. J. Phillips E. A. Aldaz W. E. Williams

1989-01-01

57

Critical experiments with mixed plutonium-uranium nitrate solutions having Pu:(Pu + U) ratios greater than 0.5  

SciTech Connect

A series of critical experiments was conducted with mixed plutonium-uranium nitrate solutions having Pu:(Pu+U) ratios >0.5. Three geometries and four conditions of reflection were examined. The plutonium concentrations ranged from 170 to 350 g/L. The value of k-effective for each experiment was calculated using the KENO-IV code and 27-group cross sections derived from the Evaluated Nuclear Data File B--version IV (ENDF/B-IV). The mean value for the set of 26 experiments was 1.003, with a minimum value of 0.987 and a maximum of 1.022. The spread in the distribution of calculated k-effectives is believed to be the result of uncertainties in analytical chemistry measurements. No correlation between condition of reflection and calculated k-effective was found. An allowable multiplication factor to be used in the evaluation of reprocessing equipment at conditions that have been investigated was calculated to be 0.945.

Primm, R.T. III [Oak Ridge National Lab., TN (United States); Lloyd, R.C.; Clayton, E.D. [Pacific Northwest Lab., Richland, WA (United States)

1986-04-01

58

Anisole Nitration During Gamma-Irradiation of Aqueous Nitrite and Nitrate Solutions: Free Radical Versus Ionic Mechanisms  

SciTech Connect

The nitration of aromatic compounds in the condensed phase is of interest to nuclear waste treatment applications. This chapter discusses our investigation of radiolytic aromatic nitration mechanisms in the condensed phase toward understanding the nitration products created during nuclear fuel reprocessing. The nitration reactions of anisole, a model aromatic compound, were studied in ?-irradiated acidic nitrate, neutral nitrate, and neutral nitrite solutions. The nitrated anisole product distributions were the same with and without radiation in acidic solution, although more products were formed with radiation. In the irradiated acidic condensed phase, radiation-enhanced nitrous acid-catalyzed nitrosonium ion electrophilic aromatic substitution followed by oxidation reactions dominated over radical addition reactions. Neutral nitrate anisole solutions were dominated by mixed nitrosonium/nitronium ion electrophilic aromatic substitution reactions, but with lower product yields. Irradiation of neutral nitrite anisole solution resulted in a statistical substitution pattern for nitroanisole products, suggesting non-electrophilic free radical reactions involving the •NO2 radical.

Gracy Elias; Bruce J. Mincher; Leigh R. Martin; Stephen P. Mezyk; Thomas D. Cullen

2010-04-01

59

SEPARATION OF URANIUM, PLUTONIUM AND FISSION PRODUCTS  

DOEpatents

The separation of uranium and plutonium from neutronirradiated uranium is described. The neutron-irradiated uranium is dissolved in nitric acid to provide an aqueous solution 3N in nitric acid. The fission products of the solution are extruded by treating the solution with dibutyl carbitol substantially 1.8N in nitric acid. The organic solvent phase is separated and neutralized with ammonium hydroxide and the plutonium reduced with hydroxylamine base to the trivalent state. Treatment of the mixture with saturated ammonium nitrate extracts the reduced plutonium and leaves the uranium in the organic solvent.

Nicholls, C.M.; Wells, I.; Spence, R.

1959-10-13

60

SEPARATION OF URANIUM, PLUTONIUM, AND FISSION PRODUCTS  

DOEpatents

Uranium and plutonium can be separated from neutron-lrradiated uranium by a process consisting of dissolvlng the lrradiated material in nitric acid, saturating the solution with a nitrate salt such as ammonium nitrate, rendering the solution substantially neutral with a base such as ammonia, adding a reducing agent such as hydroxylamine to change plutonium to the trivalent state, treating the solution with a substantially water immiscible organic solvent such as dibutoxy diethylether to selectively extract the uranium, maklng the residual aqueous solutlon acid with nitric acid, adding an oxidizing agent such as ammonlum bromate to oxidize the plutonium to the hexavalent state, and selectlvely extracting the plutonium by means of an immlscible solvent, such as dibutoxy dlethyletber.

Spence, R.; Lister, M.W.

1958-12-16

61

Aqueous nitrate waste treatment: Technology comparison, cost/benefit, and market analysis  

SciTech Connect

The purpose of this analysis is to provide information necessary for the Department of Energy (DOE) to evaluate the practical utility of the Nitrate to Ammonia and Ceramic or Glass (NAC/NAG/NAX) process, which is under development in the Oak Ridge National Laboratory. The NAC/NACx/NAX process can convert aqueous radioactive nitrate-laden waste to a glass, ceramic, or grout solid waste form. The tasks include, but are not limited to, the following: Identify current commercial technologies to meet hazardous and radiological waste disposal requirements. The technologies may be thermal or non-thermal but must be all inclusive (i.e., must convert a radionuclide-containing nitrate waste with a pH around 12 to a stable form that can be disposed at permitted facilities); evaluate and compare DOE-sponsored vitrification, grouting, and minimum additive waste stabilization projects for life-cycle costs; compare the technologies above with respect to material costs, capital equipment costs, operating costs, and operating efficiencies. For the NAC/NAG/NAX process, assume aluminum reactant is government furnished and ammonia gas may be marketed; compare the identified technologies with respect to frequency of use within DOE for environmental management applications with appropriate rationale for use; Assess the potential size of the DOE market for the NAC/NAG/NAX process; assess and off-gas issues; and compare with international technologies, including life-cycle estimates.

Not Available

1994-01-01

62

Preliminary studies of thin metal oxide films prepared by deposition of an aerosol generated ultrasonically from aqueous nitrate solutions  

Microsoft Academic Search

Thin Co, Co-Fe and Co-Fe-Cr metal oxide films were prepared by deposition of an aerosol generated by ultrasonic excitations from aqueous nitrate solutions. Commercial gray glass has been used as substrates. Thermogravimetric (TG and DTG) measurements of initial nitrate components as well as their homogenized mixtures were performed and optical properties, i.e. reflectance and transmittance of the deposited films in

M. Jergel; M. Garcia; A. Condegallardo; C. Falcony; M. A. Canseco; G. Plesch

1997-01-01

63

Anisole nitration during gamma-irradiation of aqueous nitrite and nitrate solutions: Free radical versus ionic mechanisms  

SciTech Connect

Radiolytic aromatic nitration mechanisms in the condensed phase are ubiquitous, and especially of interest in atmospheric aerosol chemistry, water treatment by advanced oxidation technologies, and nuclear fuel reprocessing. Here, the radiolytically-induced nitration reactions of anisole, the simplest aryl alkyl ether, were investigated in ?-irradiated acidic nitrate solution, and in neutral nitrate and nitrite solutions. The nitrated anisole product distribution was the same with and without radiation in acidic solution, although more products were formed as a result of irradiation. This suggests that the mechanism of nitration in acidic solution is nitronium ion- induced electrophilic aromatic substitution. The rate of production of nitrated products in neutral nitrate solution was much lower, although the distribution of isomers was similar to that expected for nitronium ion electrophilic nitration. In contrast, the product distribution in neutral nitrite solution approached a statistically random substitution pattern, suggesting a non-electrophilic free radical reaction involving •NO2 radical. When hydroxyl radical (•OH) was scavenged by varying the initial nitrite concentration, the concentration of nitrated products increased with increasing nitrite, indicating that the reaction was probably one of direct •NO2 radical addition. However, this latter mechanism will not be important in acidic solutions, such as those often encountered in atmospheric aerosols or ?-irradiated nuclear fuel reprocessing solutions, due to low amounts of produced •NO2 radical and the low reaction rate constants for the •NO2 radical with aromatic compounds.

Gracy Elias; Bruce J. Mincher; Leigh R. Martin; Stephen P. Mezyk; Thomas Cullen

2010-04-01

64

Determination of a Cold Substitute for Plutonium Nitrate (Pu(NO Sub 3 ) sub 4 ) Calcination.  

National Technical Information Service (NTIS)

This activity researched candidate cold substitutes for Pu(NO sub 3 ) sub 4 needed to test prototype screw calciners for PuO sub 2 production. Cerous nitrate, (Ce(NO sub 3 ) sub 3 .6H sub 2 O), was identified as the most promising substitute. Four compoun...

J. T. D'Ambrosia

1979-01-01

65

Anion exchange resin applied to a separation between nitrate and chloride ions in the presence of aqueous soluble polyelectrolyte  

Microsoft Academic Search

Removal of nitrate anion from aqueous solution stays one of the principal goals of much study concerning water treatment. Besides biological and membrane separation treatment, Anion exchange resin technique has been widely investigated and the most result was leading to an efficient elimination. In the proposed work an attempt to the utilization of commercial anion exchange membrane modified by adsorption

Yassine Berbar; Mourad Amara; Hacène Kerdjoudj

2008-01-01

66

Some features of the overoxidation of polypyrrole synthesized on austenitic stainless steel electrodes in aqueous nitrate solutions  

Microsoft Academic Search

The overoxidation of polypyrrole (Ppy) films in aqueous nitrate solutions is studied via cyclic voltammetry and in situ spectroelectrochemical measurements. During the potentiodynamic growth of Ppy on austenitic stainless steel electrodes, the onset of overoxidation is observed at 1.3 V saturated calomel electrode (SCE). Voltammograms of the films obtained near and far from the threshold of overoxidation show remarkable differences.

I. Fernández; M. Trueba; C. A. Núñez; J. Rieumont

2005-01-01

67

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

68

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

69

Criticality experiments with mixed plutonium and uranium nitrate solution at a plutonium fraction of 0.5 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 0.5. 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 cylindrical and slab geometries and included measurements with a water reflector, a concrete reflector, and without an added reflector. The concentration was varied from 112 to 332 g (Pu + U)/liter. The ratio of plutonium to total heavy metal (plutonium plus uranium) was 52% for all experiments.

Lloyd, R.C.

1986-12-01

70

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

71

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

2012-11-17

72

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

73

Caffeine as non-toxic corrosion inhibitor for copper in aqueous solutions of potassium nitrate  

NASA Astrophysics Data System (ADS)

Different electrochemical methods were employed in order to confirm the ability of caffeine (1,3,7-trimethylxanthine) to inhibit the corrosion processes of copper in aqueous potassium nitrate solutions in the absence and in the presence of chloride. Some experiments were repeated in potassium perchlorate in order to compare the influence of the medium. The interaction between the organic compound and the electrode surface occurs independently of the electrode potential. However, maximum interaction was observed at 0.0 V (Ag/AgCl) in aerated solutions, and at -0.25 V (Ag/AgCl) in deaerated solutions. The presence of the organic compound adsorbed on the electrode surface was confirmed by comparing the voltammograms of copper electrode in the absence and presence of 1.5 mmol L-1 of dissolved caffeine. The same results were observed by comparing polarization curves in the absence and in the presence of caffeine. Anodic currents decrease noticeably in the presence of the organic compound. Chronoamperometric experiments were conclusive to prove the inhibitor capability of caffeine to decrease the corrosion dissolution processes of copper under anodic polarization.

Fallavena, Thuanny; Antonow, Muriel; Gonçalves, Reinaldo Simões

2006-11-01

74

Hardness and Salt Effects on Catalytic Hydrogenation of Aqueous Nitrate Solutions  

Microsoft Academic Search

Liquid-phase hydrogenation using a solid Pd–Cu bimetallic catalyst provides a potential technique for the removal of nitrates from waters. In this study, hardness and salt effects on both the nitrate disappearance rate and the reaction selectivity were quantitatively evaluated. Reduction experiments were performed for a wide range of nitrate conversions in an isothermal semibatch slurry reactor. It was discovered in

Albin Pintar; Marko vSetinc; Janez Levec

1998-01-01

75

New reagent for uranium - plutonium partitioning.  

National Technical Information Service (NTIS)

We have investigated the feasibility of achieving uranium-plutonium partition of the Purex Process by using a new reagent: Uranous nitrate - hydroxylamine nitrate. Laboratory test tube studies and uranium-plutonium partitioning runs have shown that pluton...

M. Germain B. Gillet J. Y. Pasquiou

1990-01-01

76

Thermodynamics of Aqueous Mixtures of Electrolytes and Nonelectrolytes. Iii. Transfer of Acetic Acid from Water to Nine 1M Alkali Halides and Nitrates at 25C.  

National Technical Information Service (NTIS)

Partial molal enthalpies of transfer of undissociated acetic acid from water to aqueous 1 m solutions of the chlorides, bromides, and nitrates of lithium, sodium, and potassium were determined calorimetrically at 25C. The enthalpies range from -225 to 106...

J. H. Stern J. P. Sandstrom A. Hermann

1967-01-01

77

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

78

Process for the preparation of pulverulent metallic oxides from metallic nitrates  

US Patent & Trademark Office Database

Process for the preparation of pulverulent metallic oxides with predetermined reactivity which is adjusted by the specific surface area, which are intended to be subjected to subsequent conversions, by thermal treatment of corresponding nitrates in the form of an aqueous solution or of a solids material, consisting of hydrated uranyl nitrate, on its own or in admixture with at least one of thorium nitrate, cerium nitrate and plutonium nitrate, which process is characterized in that it consists of two treatment stages: (a) the first stage essentially consisting of incompletely dehydrating the hydrated uranyl nitrate. (b) the second stage essentially consisting of decomposing the product resulting from the first stage by calcination under controlled steam pressure. The process is used for obtaining uranium oxide on its own or in admixture with thorium oxide, cerium oxide and plutonium oxide, with a view to subsequent chemical conversions and/or sintering.

1987-08-18

79

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

80

Ion Exchange Automatic Elution System Used in the Full-Scale Aqueous Scrap Purification of Plutonium-238 Dioxide  

SciTech Connect

The Aqueous Scrap Recovery process at Los Alamos is designed to produce pure Plutonium Oxide (238PuO2) from scrap or impure sources. The incoming 238PuO2 contains a significant amount of impurities that must be removed before it can be processed any further. One of the purification steps involves the ion exchange process. This process sorbs the putative [Pu(NO3)6]2- dianion onto an anion exchange resin (Reillex{sup TM} HPQ), while impurities are washed from the Pu sorbed resin. Most impurities in the solution do not sorb to the resin and are part of the effluent stream. During the wash cycle, 7 M of nitric acid is pumped through the resin column to wash the resin of unsorbed impurities. The solution collected (with impurities) is the wash stream. In some cases, an online gamma spectrophotometer is used to monitor the wash stream for 234U and 241Am, and ensures that a large percentage of these isotopes have washed through the column, indicating efficient separation from the plutonium. In the final step of the process, the Pu is released (desorbed) from the resin by pumping eluant through the column during the elution cycle. Typically, the eluant used to desorb the plutonium is 0.45 M HNO3. The focus of this presentation discusses an automated elution process that has been incorporated into the system used at Los Alamos in the event that the operators must vacate the laboratory in the case of an emergency. The automated elution process is triggered by temperature, pressure, and liquid level signals being monitored on both Ion Exchange columns. The automated system relies on the commercially available Lookout{sup TM} software to control each pump and valve in the system and is programmed to perform an automatic elution for a preset time if any of the operational limiting conditions are met.

Matonic, John H.; Teague, Jonathan G.; Spengler, Diane J.; Dinh, Peter [238Pu Science and Engineering (NMT-9), Nuclear Materials and Technology Division, Los Alamos National Laboratory, Los Alamos, NM, 87545 (United States)

2005-02-06

81

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

82

Laboratory-scale evaluations of alternative plutonium precipitation methods  

Microsoft Academic Search

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

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

1984-01-01

83

Simultaneous electrochemical determination of nitrate and nitrite in aqueous solution using Ag-doped zeolite-expanded graphite-epoxy electrode.  

PubMed

In this work a new electrochemical sensor based on an Ag-doped zeolite-expanded graphite-epoxy composite electrode (AgZEGE) was evaluated as a novel alternative for the simultaneous quantitative determination of nitrate and nitrite in aqueous solutions. Cyclic voltammetry was used to characterize the electrochemical behavior of the electrode in the presence of individual or mixtures of nitrate and nitrite anions in 0.1M Na(2)SO(4) supporting electrolyte. Linear dependences of current versus nitrate and nitrite concentrations were obtained for the concentration ranges of 1-10mM for nitrate and 0.1-1mM for nitrite using cyclic voltammetry (CV), chronoamperometry (CA), and multiple-pulsed amperometry (MPA) procedures. The comparative assessment of the electrochemical behavior of the individual anions and mixtures of anions on this modified electrode allowed determining the working conditions for the simultaneous detection of the nitrite and nitrate anions. Applying MPA allowed enhancement of the sensitivity for direct and indirect nitrate detection and also for nitrite detection. The proposed sensor was applied in tap water samples spiked with known nitrate and nitrite concentrations and the results were in agreement with those obtained by a comparative spectrophotometric method. This work demonstrates that using multiple-pulse amperometry with the Ag-doped zeolite-expanded graphite-epoxy composite electrode provides a real opportunity for the simultaneous detection of nitrite and nitrate in aqueous solutions. PMID:21035645

Manea, Florica; Remes, Adriana; Radovan, Ciprian; Pode, Rodica; Picken, Stephen; Schoonman, Joop

2010-09-20

84

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.; 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. PMID:24145916

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

2013-10-18

85

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

86

Plutonium Chemistry in the UREX+ Separation Processes  

SciTech Connect

The project "Plutonium Chemistry in the UREX+ Separation Processes” is led by Dr. Alena Paulenova of Oregon State University under collaboration with Dr. George Vandegrift of ANL and Dr. Ken Czerwinski of the University of Nevada at Las Vegas. The objective of the project is to examine the chemical speciation of plutonium in UREX+ (uranium/tributylphosphate) extraction processes for advanced fuel technology. Researchers will analyze the change in speciation using existing thermodynamics and kinetic computer codes to examine the speciation of plutonium in aqueous and organic phases. They will examine the different oxidation states of plutonium to find the relative distribution between the aqueous and organic phases under various conditions such as different concentrations of nitric acid, total nitrates, or actinide ions. They will also utilize techniques such as X-ray absorbance spectroscopy and small-angle neutron scattering for determining plutonium and uranium speciation in all separation stages. The project started in April 2005 and is scheduled for completion in March 2008.

ALena Paulenova; George F. Vandegrift, III; Kenneth R. Czerwinski

2009-10-01

87

Purification of plutonium  

SciTech Connect

During the reprocessing of irradiated nuclear fuel by solvent extraction techniques a primary separation to give a uranium containing product stream and a plutonium containing product stream occurs. The plutonium in the plutonium containing stream is separated from neptunium and uranium by bringing a solution containing plutonium, neptunium and uranium in an organic solvent into contact first with an aqueous solution of a hydroxylamine and/or a hydrazine salt at 30/sup 0/ to 35/sup 0/ C. To preferentially reduce the neptunium and to extract it into the aqueous phase and then bringing the organic solution containing plutonium and uranium into contact with an aqueous phase containing a hydroxylamine and a hydrazine salt at about 50/sup 0/ C. To preferentially reduce the plutonium and to extract it into the aqueous phase leaving the uranium in the organic solvent.

Chapman, E.S.; Smith, W.

1980-10-21

88

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

89

PROCESS FOR PURIFYING PLUTONIUM  

DOEpatents

A method is described of separating plutonium from small amounts of uranium and other contaminants. An acidic aqueous solution of higher valent plutonium and hexavalent uranium is treated with a soluble iodide to obtain the plutonium in the plus three oxidation state while leaving the uranium in the hexavalent state, adding a soluble oxalate such as oxalic acid, and then separating the insoluble plus the plutonium trioxalate from the solution.

Mastick, D.F.; Wigner, E.P.

1958-05-01

90

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

91

Acid-catalyzed oxidation of 2,4-dichlorophenoxyacetic acid by ammonium nitrate in aqueous solution  

SciTech Connect

2,4-Dichlorophenoxyacetic acid (2,4-D) was oxidized to CO{sub 2} and water by homogeneous, liquid-phase reaction with ammonium nitrate at temperatures between 250 and 450{degree}F and pressures below 100 psi. N{sub 2} and N{sub 2}O were produced from the thermal decomposition of the ammonium nitrate oxidant. An unexpected maximum in conversion was observed at an intermediate reaction temperature, which was consistent with rapid thermal decomposition of the NH{sub 4}NO{sub 3} oxidant. Postulated reaction pathways consisting of simultaneous oxidation of 2,4-D and decomposition of the oxidant allowed estimation of kinetic constants from best-fit analysis of the data. The proposed reaction model provided a mathematical description of 2,4-D conversion, which allowed extrapolation of the results to reaction conditions and reactor configurations that were not experimentally investigated.

Leavitt, D.D.; Abraham, M.A. (Univ. of Tulsa, OK (USA))

1990-04-01

92

Salting-out of isopropyl alcohol from aqueous solutions with potassium nitrate  

Microsoft Academic Search

The solubility of components and critical phenomena in a ternary system constituted by potassium nitrate, water, and isopropyl alcohol were studied by the visual-polythermic method in the temperature range 25–90°C. The formation temperature of the critical node of the monotectic equilibrium (critical solution—solid phase) and the solution compositions corresponding to the critical solubility points at different temperatures were determined. Isothermal

S. I. Sinegubova; K. K. Il’in; D. G. Cherkasov; V. F. Kurskii; N. V. Tkachenko

2004-01-01

93

A study of carbon dioxide absorption into aqueous monoethanolamine solution containing calcium nitrate in the gas–liquid reactive precipitation of calcium carbonate  

Microsoft Academic Search

The influence of calcium nitrate on the process of carbon dioxide absorption in aqueous monoethanolamine (MEA) solution has been considered. The experimental data obtained under typical conditions used for the industrial precipitation of calcium carbonate has been used to determine the speciation in solution and the supersaturation profile in the bulk liquid by means of a specially developed algorithm as

M Vu?ak; J Peri?; A Žmiki?; M. N Pons

2002-01-01

94

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

95

Continuous plutonium dissolution apparatus  

DOEpatents

This invention is concerned with continuous dissolution of metals such as plutonium. A high normality acid mixture is fed into a boiler vessel, vaporized, and subsequently condensed as a low normality acid mixture. The mixture is then conveyed to a dissolution vessel and contacted with the plutonium metal to dissolve the plutonium in the dissolution vessel, reacting therewith forming plutonium nitrate. The reaction products are then conveyed to the mixing vessel and maintained soluble by the high normality acid, with separation and removal of the desired constituent. (Official Gazette)

Meyer, F.G.; Tesitor, C.N.

1974-02-26

96

Laboratory-Scale Evaluations of Alternative Plutonium Precipitation Methods.  

National Technical Information Service (NTIS)

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 compare...

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

1984-01-01

97

Solubility and reactivity of peroxyacetyl nitrate (PAN) in dilute aqueous salt solutions and in sulphuric acid  

Microsoft Academic Search

The loss rates of PAN in several dilute aqueous salt solutions (NaBr, Na2SO3, KI, NaNO2, FeCl3, and FeSO4) and in sulphuric acid were measured at 279K with a simple bubbler experiment. They are little different from that in pure water. For 5M sulphuric acid hydrolysis and solubility were determined in the temperature range of 243–293K. The hydrolysis rate kh=3.2×10?4s?1 at

A Frenzel; S Kutsuna; K Takeuchi; T Ibusuki

2000-01-01

98

Delta-plutonium dissolving: A HAN process.  

National Technical Information Service (NTIS)

This report describes preliminary studies in the development of a nitrate-based method for dissolving delta-phase plutonium. The dissolving solution, a mixture of nitric acid, hydroxylammonium nitrate (HAN) and fluoride offers substantial advantages over ...

D. G. Karraker

1990-01-01

99

Mercury adsorption on granular activated carbon in aqueous solutions containing nitrates and chlorides.  

PubMed

Adsorption is an effective process to remove mercury from polluted waters. In spite of the great number of experiments on this subject, the assessment of the optimal working conditions for industrial processes is suffering the lack of reliable models to describe the main adsorption mechanisms. This paper presents a critical analysis of mercury adsorption on an activated carbon, based on the use of chemical speciation analysis to find out correlations between mercury adsorption and concentration of dissolved species. To support this analysis, a comprehensive experimental study on mercury adsorption at different mercury concentrations, temperatures and pH was carried out in model aqueous solutions. This study pointed out that mercury capture occurs mainly through adsorption of cationic species, the adsorption of anions being significant only for basic pH. Furthermore, it was shown that HgOH(+) and Hg(2+) are captured to a higher extent than HgCl(+), but their adsorption is more sensitive to solution pH. Tests on the effect of temperature in a range from 10 to 55 °C showed a peculiar non-monotonic trend for mercury solution containing chlorides. The chemical speciation and the assumption of adsorption exothermicity allow describing this experimental finding without considering the occurrence of different adsorption mechanisms at different temperature. PMID:21803490

Di Natale, F; Erto, A; Lancia, A; Musmarra, D

2011-07-12

100

ELECTRODEPOSITION OF PLUTONIUM  

DOEpatents

A process of electrolytically recovering plutonium from dilute aqueous solutions containing plutonium ions comprises electrolyzing the solution at a current density of about 0.44 ampere per square centimeter in the presence of an acetate-sulfate buffer while maintaining the pH of the solution at substantially 5 and using a stirred mercury cathode.

Wolter, F.J.

1957-09-10

101

Hollow fiber supported liquid membrane: a novel technique for separation and recovery of plutonium from aqueous acidic wastes  

Microsoft Academic Search

Low plutonium content acidic waste is generated in nuclear chemical facilities. Study was initiated to develop hollow fiber supported liquid membrane (HFSLM) technique for quantitative separation and recovery of plutonium (Pu) from such wastes using tri-n-butyle phosphate (TBP) in dodecane as carrier. Hollow fiber test module was fabricated using 20 lumens of 33.91cm2 surface area and 9cm length. After satisfactory

N. S Rathore; J. V Sonawane; Anil Kumar; A. K Venugopalan; R. K Singh; D. D Bajpai; J. P Shukla

2001-01-01

102

SOLVENT EXTRACTION PROCESS FOR PLUTONIUM  

DOEpatents

A process of separating plutonium in at least the tetravalent state from fission products contained in an aqueous acidic solution by extraction with alkyl phosphate is reported. The plutonium can then be back-extracted from the organic phase by contact with an aqueous solution of sulfuric, phosphoric, or oxalic acid as a complexing agent.

Anderson, H.H.; Asprey, L.B.

1960-02-01

103

PROCESS OF ELIMINATING HYDROGEN PEROXIDE IN SOLUTIONS CONTAINING PLUTONIUM VALUES  

Microsoft Academic Search

A procedure is given for peroxide precipitation processes for separating ; and recovering plutonium values contained in an aqueous solution. When plutonium ; peroxide is precipitated from an aqueous solution, the supernatant contains ; appreciable quantities of plutonium and peroxide. It is desirable to process ; this solution further to recover plutonium contained therein, but the presence of ; the

J. G. Barrick; B. A. Fries

1960-01-01

104

PREPARATION OF HALIDES OF PLUTONIUM  

DOEpatents

A dry chemical method is described for preparing plutonium halides, which consists in contacting plutonyl nitrate with dry gaseous HCl or HF at an elevated temperature. The addition to the reaction gas of a small quantity of an oxidizing gas or a reducing gas will cause formation of the tetra- or tri-halide of plutonium as desired.

Garner, C.S.; Johns, I.B.

1958-09-01

105

Method of Dissolving Plutonium with Sulfamic Acid.  

National Technical Information Service (NTIS)

The dissolution of plutonium metal is required in various nuclear fuel processes, for example, as a preliminary step to solvent extraction. Plutonium metal is contacted with aqueous sulfamic acid in a stainless steel container until dissolution. The conta...

W. J. Jenkins

1965-01-01

106

CONCENTRATION AND DECONTAMINATION OF SOLUTIONS CONTAINING PLUTONIUM VALUES BY BISMUTH PHOSPHATE CARRIER PRECIPITATION METHODS  

DOEpatents

A process is given for isolating plutonium present in the tetravalent state in an aqueous solution together with fission products. First, the plutonium and fission products are coprecipitated on a bismuth phosphate carrier. The precipitate obtained is dissolved, and the plutonium in the solution is oxidized to the hexavalent state (with ceric nitrate, potassium dichromate, Pb/ sub 3/O/sub 4/, sodium bismuthate and/or potassium dichromate). Thereafter a carrier for fission products is added (bismuth phosphate, lanthanum fluoride, ceric phosphate, bismuth oxalate, thorium iodate, or thorium oxalate), and the fission-product precipitation can be repeated with one other of these carriers. After removal of the fission-product-containing precipitate or precipitates. the plutonium in the supernatant is reduced to the tetravalent state (with sulfur dioxide, hydrogen peroxide. or sodium nitrate), and a carrier for tetravalent plutonium is added (lanthanum fluoride, lanthanum hydroxide, lanthanum phosphate, ceric phosphate, thorium iodate, thorium oxalate, bismuth oxalate, or niobium pentoxide). The plutonium-containing precipitate is then dissolved in a relatively small volume of liquid so as to obtain a concentrated solution. Prior to dissolution, the bismuth phosphate precipitates first formed can be metathesized with a mixture of sodium hydroxide and potassium carbonate and plutonium-containing lanthanum fluorides with alkali-metal hydroxide. In the solutions formed from a plutonium-containing lanthanum fluoride carrier the plutonium can be selectively precipitated with a peroxide after the pH was adjusted preferably to a value of between 1 and 2. Various combinations of second, third, and fourth carriers are discussed.

Seaborg, G.T.; Thompson, S.G.

1960-08-23

107

Heavy-metal-induced Inhibition of Aspergillus niger nitrate reductase: Applications for Rapid Contaminant Detection in Aqueous Samples  

SciTech Connect

Enzyme inhibition assays have the potential to rapidly screen and identify heavy metals in environmental samples. Inhibition of nitrate reductase (NR) was examined as a method for detecting toxic metals. The activity of NR (EC 1.6.6.2) from Aspergillus niger was assayed as a function of metal concentration in the presence of Cd2+, Cr3+, Cr6+, Cu2+, Ni2+, Pb2+, and Zn2+. NR exhibited sensitivity to these metals at concentrations below 10 µM. Various buffers were screened for their ability to protect NR activity from metal inhibition, and 3-(N-morpholino) propanesulfonic acid (MOPS) was selected as the buffering system for the NR assays as it exhibited the least interference with metal inhibition, thus providing increased assay sensitivity. The hypothesis that chelating agents could prevent the inhibition of NR activity by metal ions was also tested. Results indicated that 10 mM ethylenediaminetetraacetic acid (EDTA) could protect NR activity from inhibition by Cr3+, Cu2+, Cd2+, Ni2+, and Zn2+ at concentrations below 100 µM, but that the EDTA had no effect on NR inhibition by Cr6+. An amount of 10 mM nitrilotriacetic acid (NTA) prevented NR inhibition by Cd2+, Cu2+, Ni2+, Pb2+, and Zn2+ at metal concentrations below 100 µM. However, 10 mM NTA was unable to protect the enzyme from inhibition by either Cr3+ or Cr6+. These results indicated that through specific metal chelation, a NR-based method for individually quantifying Cr3+ and Cr6+ species in aqueous solutions could be developed. The ability to restore activity to NR which been previously inhibited by exposure to 100 µM Pb2+, Cd2+, Zn2+, Cu2+, and Cr3+ was explored to determine whether NR activity could be recovered by EDTA additions for use in consecutive metal inhibition assays. The results showed NR activity could not be regained after exposure to Cr3+ or Cu2+, but did partially recover activity after Cd2+, Pb2+, and Zn2+ exposure.

Apel, William Arnold; Aiken, Abigail Marie; Peyton, Brent Michael; Petersen, James N.

2003-03-01

108

Chloride removal from plutonium alloy  

Microsoft Academic Search

SRP is evaluating a program to recover plutonium from a metallic alloy that will contain chloride salt impurities. Removal of chloride to sufficiently low levels to prevent damaging corrosion to canyon equipment is feasible as a head-end step following dissolution. Silver nitrate and mercurous nitrate were each successfully used in laboratory tests to remove chloride from simulated alloy dissolver solution

1983-01-01

109

Thermochemical nitrate destruction  

SciTech Connect

The thermochemical destruction of nitrate was conducted in an aqueous media. Six reducing agents (ammonia, formate, urea, glucose, methane, and hydrogen) were mixed separately with 3 wt % NO[sub 3][sup [minus

Cox, J.L.; Hallen, R.T.; Lilga, M.A. (Pacific Northwest Lab., Richland, WA (United States))

1994-03-01

110

Investigation of Selectivity and Kinetic Behavior of Strong?Base Ion Exchange Resin Purolite A 520E for Nitrate Removal from Aqueous Solution  

Microsoft Academic Search

The aim of this work is to present experimental results on the removal of nitrate by nitrate selective ion exchange resin, Purolite A 520E. The resin particle size, nitrate concentration, temperature, and stirring speed were investigated as experimental parameters and the optimum conditions for nitrate removal were determined. Nitrate removal by strong base anion exchange resin Purolite A 520E was

Saba Samatya; Ümran Yüksel; Mü?erref Arda; Nalan Kabay; Mithat Yüksel

2006-01-01

111

PLUTONIUM COMPOUNDS AND PROCESS FOR THEIR PREPARATION  

DOEpatents

This patent relates to certain new compounds of plutonium, and to the utilization of these compounds to effect purification or separation of the plutonium. The compounds are organic chelate compounds consisting of tetravalent plutonium together with a di(salicylal) alkylenediimine. These chelates are soluble in various organic solvents, but not in water. Use is made of this property in extracting the plutonium by contacting an aqueous solution thereof with an organic solution of the diimine. The plutonium is chelated, extracted and effectively separated from any impurities accompaying it in the aqueous phase.

Wolter, F.J.; Diehl, H.C. Jr.

1958-01-01

112

Electric performance and photosensitivity of heterostructures prepared by thermal decomposition of a gallium nitrate aqueous solution on an indium selenide (0001) cleaved surface  

NASA Astrophysics Data System (ADS)

It is shown that thermal decomposition of a gallium nitrate aqueous solution on the surface of a semiconductor in air can basically be used for preparing structures sensitive to radiation from in the near-UV spectral range. The electric and photovoltaic properties of Ga2O3- n-( p-)InSe heterostructures are studied. It is found that a high-ohmic layer arising at the InSe-Ga2O3 interface affects not only the electric performance but also the photoelectric spectra of the heterostructures. It is supposed that current instability with Z- and N-shaped reverse branches in the I- V characteristics of the Ga2O3- p-InSe structures stems from doping nonuniformity in the bulk of quasi-two-dimensional p-type indium selenide.

Drapak, S. I.; Yurtsenyuk, N. S.; Kovalyuk, Z. D.

2009-03-01

113

METHOD FOR RECOVERING PLUTONIUM VALUES FROM SOLUTION USING A BISMUTH HYDROXIDE CARRIER PRECIPITATE  

DOEpatents

Carrier precipitation processes for separating plutonium values from aqueous solutions are described. In accordance with the invention a bismuth hydroxide precipitate is formed in the plutonium-containing solution, thereby carrying plutonium values from the solution.

Faris, B.F.

1961-04-25

114

Structural characterization of zinc(II) chloride in aqueous solution and in the protic ionic liquid ethyl ammonium nitrate by x-ray absorption spectroscopy  

NASA Astrophysics Data System (ADS)

Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to investigate the species and structures existing in a series of ZnCl2-H2O-NaCl solutions with different chloride/zinc ratios and in a solution of ZnCl2 in the protic ionic liquid ethyl ammonium nitrate (EAN). The average coordination numbers and distances of zinc species were determined from the analysis of the EXAFS data. In aqueous solution the number of chloride ions tightly bounded to Zn2+ is significantly related to the chloride/zinc ratio, and no inner complex formation between Zn2+ and Cl- ions has been detected for low ZnCl2 concentration (0.1 and 0.2 M). Conversely, in the same concentration range (0.13 M) the ZnCl2 species do not dissociate in EAN and the Zn2+ first coordination shell has two chloride ions and is completed by two oxygen atoms of the nitrate anion. The results of this investigation show that notwithstanding the existence of similar characteristics between EAN and water, the solvation properties of the two solvents are markedly different.

D'Angelo, Paola; Zitolo, Andrea; Ceccacci, Francesca; Caminiti, Ruggero; Aquilanti, Giuliana

2011-10-01

115

STUDIES ON THE EXTRACTION OF PLUTONIUM(IV) FROM AQUEOUS NITRIC ACID - OXALIC ACID BY ALIQUAT-336  

Microsoft Academic Search

The extraction of Pu(IV) by Aliquat-336 from aqueous nitric acid containing oxalic acid was studied with a view to exploring the feasibility of recovery of Pu(IV) from Pu(IV) oxalate precipitation effluents. Distribution ratio data were obtained as a function of concentration of nitric acid, oxalic acid and Aliquat-336. The data obtained revealed that Pu(IV) can be extracted almost quantitatively by

C. V. Karekar; G. Chourasiya; S. K. Patil

1983-01-01

116

PROCESS OF SEPARATING PLUTONIUM FROM URANIUM  

DOEpatents

A process is presented for recovering plutonium values from aqueous solutions. It comprises forming a uranous hydroxide precipitate in such a plutonium bearing solution, at a pH of at least 5. The plutonium values are precipitated with and carried by the uranium hydroxide. The carrier precipitate is then redissolved in acid solution and the pH is adjusted to about 2.5, causing precipitation of the uranous hydroxide but leaving the still soluble plutonium values in solution.

Brown, H.S.; Hill, O.F.

1958-09-01

117

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

118

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

119

Modeling of the Extraction of Lanthanide Nitrates from Aqueous Solutions Over a Wide Range of Activities by CMPO  

Microsoft Academic Search

A thermodynamic model that allows one to determine the number and the stoichiometry of the complexes formed between trivalent lanthanide (Ln) nitrates—Pr(NO3)3, Nd(NO3)3, Sm(NO3)3, Eu(NO3)3, Gd(NO3)3, and Yb(NO3)3—and octyl(phenyl)?N,N?diisobutylcarbamoylmethyl phosphine oxide (CMPO) diluted in nitrophenylhexyl ether (NPHE) is presented in this work. The Mikulin–Sergievskii–Dannus' model was used to model the extraction at 25°C of the Ln(NO3)3–H2O–CMPO 0.2 mol kg–NPHE system with or

S. Belair; C. Lamouroux; M. Tabarant; A. Labet; C. Mariet; P. Dannus

2004-01-01

120

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

121

PROCESS OF ELIMINATING HYDROGEN PEROXIDE IN SOLUTIONS CONTAINING PLUTONIUM VALUES  

DOEpatents

A procedure is given for peroxide precipitation processes for separating and recovering plutonium values contained in an aqueous solution. When plutonium peroxide is precipitated from an aqueous solution, the supernatant contains appreciable quantities of plutonium and peroxide. It is desirable to process this solution further to recover plutonium contained therein, but the presence of the peroxide introduces difficulties; residual hydrogen peroxide contained in the supernatant solution is eliminated by adding a nitrite or a sulfite to this solution.

Barrick, J.G.; Fries, B.A.

1960-09-27

122

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

123

Evaluation of chloride-ion-specific electrodes as in situ chemical sensors for monitoring total chloride concentration in aqueous solutions generated during the recovery of plutonium from molten salts used in plutonium electrorefining operations  

Microsoft Academic Search

Two commercially available chloride-ion-specific electrodes (CLISEs), a solid-state type and a membrane type, were evaluated as potential in situ chemical sensors for determining total chloride ion concentration in mixed sodium chloride\\/potassium chloride\\/hydrochloric acid solutions generated during the recovery of plutonium from molten salts used in plutonium electrorefining operations. Because the response of the solid-state CLISE was closer than was the

1992-01-01

124

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

125

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

2012-09-29

126

PROCESS FOR SEPARATING PLUTONIUM FROM IMPURITIES  

DOEpatents

A method is described for separating plutonium from aqueous solutions containing uranium. It has been found that if the plutonium is reduced to its 3+ valence state, and the uranium present is left in its higher valence state, then the differences in solubility between certain salts (e.g., oxalates) of the trivalent plutonium and the hexavalent uranium can be used to separate the metals. This selective reduction of plutonium is accomplished by adding iodide ion to the solution, since iodide possesses an oxidation potential sufficient to reduce plutonium but not sufficient to reduce uranium.

Wahl, A.C.

1957-11-12

127

EXTRACTION OF Cd(II) FROM AQUEOUS NITRATE SOLUTION BY THERMOSENSITIVE GEL CROSSLINKED WITH 2,6DI(3-VINYLBENZYL-1,2,4- TRIAZOL-5-YL)PYRIDINE (BTP)  

Microsoft Academic Search

A poly-N-isopropylacrylamide (poly-NIPA) gel crosslinked with 2,6-di(3-vinylbenzyl-1,2,4-triazol-5-yl)pyridine (BTP) was prepared by the ultrasonic polymerization technique and the extraction of Cd(II) from an aqueous nitrate solution was tested. The BTP-NIPA gel showed phase transition phenomena, in which the gel was shrunken at temperature higher than the phase transition temperature (304 K) and swollen at less than 304 K. The extraction capacity

Kenji Takeshita; Motoki Tanaka; Yoshio Nakano

2002-01-01

128

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

129

METHOD OF PREPARING PLUTONIUM TETRAFLUORIDE  

DOEpatents

C rystalline plutonium tetrafluoride is precipitated from aqueous up to 1.6 N mineral acid solutions of a plutorium (IV) salt with fluosilicic acid anions, preferably at room temperature. Hydrogen fluoride naay be added after precipitation to convert any plutonium fluosilicate to the tetrafluoride and any silica to fluosilicic acid. This process results in a purer product, especially as to iron and aluminum, than does the precipitation by the addition of hydrogen fluoride.

Beede, R.L.; Hopkins, H.H. Jr.

1959-11-17

130

Radiolytic effects of plutonium.  

SciTech Connect

Plutonium isotopes, most of them a-emitters, cause radiolytic changes in the matrix, in whic h they are embedded. The internal irradiation of Pu metal or its alloys results in physical changes, largel y as a result of the formation of helium bubbles, well-known to material scientists and weapons specialists . In all other media where plutonium occurs, usually as Pu'+ in an ionic form, the results of irradiation ar e chemical in nature. Homogenous media containing Pu, are often aqueous or non-aqueous solutions o f plutonium compounds, mostly originating during processing of spent nuclear fuel or from Pu processing . Heterogenous matrices containing plutonium are more complex from the point of view of radiolysis; they usually contain a variety of combinations of common materials contaminated with radionuclides . This class of radioactive materials represents a challenge for the management of plutonium waste . One has to consider a range of time scales for radiolytic effects (and consequently a several orders o f magnitude range of the cumulative dose) beginning with waste generation, through packaging, transportation, to the period of final storage . Final storage could be for thousands of years in deep geologic repositories . At every ' stage of that time scale, radiolysis proceeds continuously an d cumulative effects c an complicate operating procedures and final disposition . The results presented here have been obtained from experiments that have irradiated of model materials, which are typically the objects of contamination with plutonium . They were irradiated with linearly accelerated electrons up to very high dose rates, adjusted to simulate any contamination at any point on the time scale .

Zagorski, Z. (Zbigniew); Dziewinski, J. J. (Jacek J.); Conca, James L.

2003-01-01

131

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

132

WET METHOD OF PREPARING PLUTONIUM TRIBROMIDE  

DOEpatents

S> The preparation of anhydrous plutonium tribromide from an aqueous acid solution of plutonium tetrabromide is described, consisting of adding a water-soluble volatile bromide to the tetrabromide to provide additional bromide ions sufficient to furnish an oxidation-reduction potential substantially more positive than --0.966 volt, evaporating the resultant plutonium tribromides to dryness in the presence of HBr, and dehydrating at an elevated temperature also in the presence of HBr.

Davidson, N.R.; Hyde, E.K.

1958-11-11

133

RECOVERY OF PLUTONIUM BY CARRIER PRECIPITATION  

DOEpatents

A process is given for recovering plutonium from an aqueous nitric acid zirconium-containing solution of an acidity between 0.2 and 1 N by adding fluoride anions (1.5 to 5 mg/l) and precipitating the plutonium with an excess of hydrogen peroxide at from 53 to 65 deg C.

Goeckermann, R.H.

1961-04-01

134

RECOVERY OF PLUTONIUM BY CARRIER PRECIPITATION  

Microsoft Academic Search

A process is given for recovering plutonium from an aqueous nitric acid ; zirconium-containing solution of an acidity between 0.2 and 1 N by adding ; fluoride anions (1.5 to 5 mg\\/l) and precipitating the plutonium with an excess of ; hydrogen peroxide at from 53 to 65 deg C.

Goeckermann

1961-01-01

135

Pyrochemical Processing of Plutonium. Technology Review Report.  

National Technical Information Service (NTIS)

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 r...

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

1982-01-01

136

Modified titrimetric determination of plutonium using photometric end-point detection  

SciTech Connect

A method used at LASL for the accurate and precise assay of plutonium metal was modified for the measurement of plutonium in plutonium oxides, nitrate solutions, and in other samples containing large quantities of plutonium in oxidized states higher than +3. In this modified method, the plutonium oxide or other sample is dissolved using the sealed-reflux dissolution method or other appropriate methods. Weighed aliquots, containing approximately 100 mg of plutonium, of the dissolved sample or plutonium nitrate solution are fumed to dryness with an HC1O/sub 4/-H/sub 2/SO/sub 4/ mixture. The dried residue is dissolved in dilute H/sub 2/SO/sub 4/, and the plutonium is reduced to plutonium (III) with zinc metal. The excess zinc metal is dissolved with HCl, and the solution is passed through a lead reductor column to ensure complete reduction of the plutonium to plutonium (III). The solution, with added ferroin indicator, is then titrated immediately with standardized ceric solution to a photometric end point. For the analysis of plutonium metal solutions, plutonium oxides, and nitrate solutions, the relative standard deviation are 0.06, 0.08, and 0.14%, respectively. Of the elements most likely to be found with the plutonium, only iron, neptunium, and uranium interfere. Small amounts of uranium and iron, which titrate quantitatively in the method, are determined by separate analytical methods, and suitable corrections are applied to the plutonium value. 4 tables, 4 figures.

Baughman, W.J.; Dahlby, J.W.

1980-04-01

137

Extraction of rare earth metal(III) nitrates with trialkylmethylammonium nitrate from multicomponent solutions containing ammonium nitrate  

SciTech Connect

A study has been made of the extraction of rare earth elements (III) (praseodymium-lutetium, yttrium) by trialkylmethylammonium nitrate in kerosine (1.10 M) from binary and multicomponent solutions containing 1.0-3.0 M of ammonium nitrate. Physicochemical and mathematical models have been proposed for the distribution of individual lanthanides (III) depending on the composition of the initial raw material and on the total REE(III) and ammonium nitrate concentrations in the aqueous phase. The optimal concentration ranges for total REE and ammonium nitrate in the aqueous phase have been found for separating complex REE concentrates by using trialkylmethylammonium nitrate in the diluent.

Pyartman, A.K.; Puzikov, E.A.; Bogatov, K.B. [St. Petersburg Technological Institute (Russian Federation)

1994-10-20

138

Evaluation of chloride-ion-specific electrodes as in situ chemical sensors for monitoring total chloride concentration in aqueous solutions generated during the recovery of plutonium from molten salts used in plutonium electrorefining operations  

SciTech Connect

Two commercially available chloride-ion-specific electrodes (CLISEs), a solid-state type and a membrane type, were evaluated as potential in situ chemical sensors for determining total chloride ion concentration in mixed sodium chloride/potassium chloride/hydrochloric acid solutions generated during the recovery of plutonium from molten salts used in plutonium electrorefining operations. Because the response of the solid-state CLISE was closer than was the response of the membrane-type CLISE to the theoretical response predicted by the Nernst equation, the solid-state CLISE was selected for further evaluation. A detailed investigation of the characteristics of the chloride system and the corresponding CLISE response to concentration changes suggested four methods by which the CLISE could be used either as a direct, in situ sensor or as an indirect sensor through which an analysis could be performed on-line with a sample extracted from the process solution.

Smith, W.H.

1992-10-01

139

OXIDATIVE METHOD OF SEPARATING PLUTONIUM FROM NEPTUNIUM  

DOEpatents

A method is described of separating neptunium from plutonium in an aqueous solution containing neptunium and plutonium in valence states not greater than +4. This may be accomplished by contacting the solution with dichromate ions, thus oxidizing the neptunium to a valence state greater than +4 without oxidizing any substantial amount of plutonium, and then forming a carrier precipitate which carries the plutonium from solution, leaving the neptunium behind. A preferred embodiment of this invention covers the use of lanthanum fluoride as the carrier precipitate.

Beaufait, L.J. Jr.

1958-06-10

140

LABORATORY INVESTIGATIONS OF INTERACTIONS OF IRRADIATED O-XYLENE/NOX/SO2/AIR MIXTURES WITH AQUEOUS MEDIA CONTAINING SODIUM FLUORIDE, SODIUM TRIFLUOROACETATE, AMMONIUM NITRATE AND HYDROGEN PEROXIDE  

EPA Science Inventory

Laboratory experiments were conducted to investigate interactions between complex air mixtures and aqueous films containing hydrolysis products of hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) oxidation products. he experiments consisted of exposing aqueous films con...

141

Plutonium flowsheet development in miniature mixer-settlers  

SciTech Connect

Initial runs were completed in a new solvent extraction facility that has been built for testing coprocessing flowsheets with simulated LWR and FBR fuel solutions. The equipment, which is assembled in glove boxes, includes three 16-stage miniature mixer-settler banks with associated in-line monitors, pumping equipment, and sampling apparatus. Following shakedown runs with solutions containing uranium only, two flowsheet test runs were made with a simulated LWR fuel solution (U/Pu = 100). The solution was fed to an extraction-scrub bank, where 30% tributyl phosphate in normal paraffin hydrocarbon diluent was used to coextract uranium and plutonium. The extract was fed to a second mixer-settler bank, where all of the plutonium was stripped into an aqueous product stream using hydroxylamine nitrate for plutonium reduction; a controlled fraction of the uranium was simultaneously stripped to produce a U/Pu ratio of {similar_to}2. The amount of the uranium stripped with the plutonium was regulated by careful control of an organic backscrub stream. Finally, the residual uranium in the solvent was stripped in the third mixer-settler bank. The success of the experiments depended on precise control of very low liquid flow rates, and on in-line monitors which indicated the uranium or total heavy-metal concentrations. The most useful in-line device was the Mettler-Paar density meter, from which metal concentrations could be determined to within {similar_to}1 g/L. A miniature spectrophotometer also gave promising results for uranium analysis. Preliminary use of a Hewlett-Packard data acquisition system was satisfactory; recorded variables were temperature, solution density, liquid flow rates, and liquid levels.

Hannaford, B.A.; Davis, G.D.

1981-05-01

142

Supported Extractant Membranes for Americium and Plutonium Recovery  

Microsoft Academic Search

Solid supported liquid membranes(SLM) are useful in transferring and concentrating americium and plutonium from nitrate solutions. Specifically, DHDECMP (d ihexyl-N, N-diethylcarbamoyImethylphosphonate) supported on Accurel or Celgard polypropylene hollow fibers assembled in modular form transfers >95% of the americium and >70% of the plutonium from high nitrate (6.9 M), low acid (0.1 M) feeds into 0.25 M oxalic acid stripping solution.

Anthony C. Muscatello; James D. Navratil; Milton E. Killion; Marlene Y. Price

1987-01-01

143

Skeletal lesions from inhaled plutonium in beagles  

SciTech Connect

The report briefly reviews the skeletal effects observed in ongoing lifespan studies in beagle dogs at 13, 10, and 7 years, respectively, after inhalation exposure to /sup 239/Pu oxide and nitrate or /sup 238/Pu oxide. Plutonium nitrate was chosen to represent soluble material more readily translocated to bone and other tissues than the oxide. Bone lesions related to plutonium exposure were observed only in dogs exposed to /sup 238/Pu oxide and /sup 239/Pu nitrate. The skeleton accumulated approximately 2% (/sup 239/Pu oxide), 45% (/sup 238/Pu oxide) or 50% (/sup 239/Pu nitrate) of the final body burdens at 13, 10, and 7 years, respectively, after exposure. 11 references, 2 figures. (ACR)

Dagle, G.E.; Park, J.F.; Weller, R.E.; Ragan, H.A.; McClanahan, B.J.; Fisher, D.R.

1984-10-01

144

Effect of Fluoride and Aluminum on the Anion Exchange of Plutonium from Nitric Acid.  

National Technical Information Service (NTIS)

Anion exchange in nitric acid is a prominent aqueous process used to recover and purify plutonium from impure nuclear materials. This process is sensitive to fluoride ion, which complexes plutonium in competition with the anionic nitrato complex that is s...

S. F. Marsh

1987-01-01

145

Non-Destructive Measurement of Solid Plutonium Waste at Los Alamos National Laboratory.  

National Technical Information Service (NTIS)

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 p...

J. R. Wachter

1989-01-01

146

Removal of Sulfamic Acid from Plutonium Sulfamate--Sulfamic Acid Solution.  

National Technical Information Service (NTIS)

Plutonium metal can be readily dissolved in aqueous solutions of sulfamic acid. When the plutonium sulfamate--sulfamic acid solutions are added to normal purex process streams, the sulfamate ion is oxidized by addition of sodium nitrite. This generates so...

L. W. Gray

1978-01-01

147

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

148

PROCESS OF REMOVING PLUTONIUM VALUES FROM SOLUTION WITH GROUP IVB METAL PHOSPHO-SILICATE COMPOSITIONS  

DOEpatents

A process for separating plutonium values from aqueous solutions which contain the plutonium in minute concentrations is described. These values can be removed from an aqueous solution by taking an aqueous solution containing a salt of zirconium, titanium, hafnium or thorium, adding an aqueous solution of silicate and phosphoric acid anions to the metal salt solution, and separating, washing and drying the precipitate which forms when the two solutions are mixed. The aqueous plutonium containing solution is then acidified and passed over the above described precipi-tate causing the plutonium values to be adsorbed by the precipitate.

Russell, E.R.; Adamson, A.W.; Schubert, J.; Boyd, G.E.

1957-10-29

149

21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.  

Code of Federal Regulations, 2010 CFR

... true Silver nitrate and hydrogen peroxide solution. 172.167 Section...172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution...mixture of silver nitrate and hydrogen peroxide may be safely used in...

2010-01-01

150

21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.  

Code of Federal Regulations, 2013 CFR

... false Silver nitrate and hydrogen peroxide solution. 172.167 Section...172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution...mixture of silver nitrate and hydrogen peroxide may be safely used in...

2013-04-01

151

21 CFR 172.167 - Silver nitrate and hydrogen peroxide solution.  

Code of Federal Regulations, 2010 CFR

... false Silver nitrate and hydrogen peroxide solution. 172.167 Section...172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution...mixture of silver nitrate and hydrogen peroxide may be safely used in...

2009-04-01

152

METHOD OF IMPROVING THE CARRIER PRECIPITATION OF PLUTONIUM  

DOEpatents

Plutonium values can be recovered from acidic solutlons by adding lead nitrate, hydrogen fluoride, lantha num nitrate, and sulfurlc acid to the solution to form a carrler preclpitate. The lead sulfate formed improves the separatlon characteristics of the lanthanum fluoride carrier precipitate,

Kamack, H.J.; Balthis, J.H.

1958-12-01

153

A direct carbon-13 and nitrogen-15 NMR study of europium(III) complexation-nitrate and europium(III)-isothiocyanate complexation in aqueous solvent mixtures  

Microsoft Academic Search

A direct, low-temperature nuclear magnetic resonance spectroscopic study of europium(III)-nitrate contact ion-pairing has been completed, and preliminary results for europium(III)-isothiocyanate have been obtained. In water-acetone-Freon mixtures, at -110°C to -120°C, four15N NMR signals are observed for coordinated nitrate ion. Area evaluations of the signals and their concentration dependence indicate the formation of Eu(NO3)2+, Eu(NO3)21+, and two higher complexes, possibly the

A. Fratiello; V. Kubo-Anderson; E. Bolanos; O. Chavez; J. Ortega; R. D. Perrigan; F. Reyes; L. Saenz; S. M. Stoll; T. Thompson

1996-01-01

154

PROCESS FOR SEPARATING PLUTONIUM BY REPEATED PRECIPITATION WITH AMPHOTERIC HYDROXIDE CARRIERS  

DOEpatents

A multiple carrier precipitation method is described for separating and recovering plutonium from an aqueous solution. The hydroxide of an amphoteric metal is precipitated in an aqueous plutonium-containing solution. This precipitate, which carries plutonium, is then separated from the supernatant liquid and dissolved in an aqueous hydroxide solution, forming a second plutonium- containing solution. lons of an amphoteric metal which forms an insoluble hydroxide under the conditions existing in this second solution are added to the second solution. The precipitate which forms and which carries plutonium is separated from the supernatant liquid. Amphoteric metals which may be employed are aluminum, bibmuth, copper, cobalt, iron, lanthanum, nickel, and zirconium.

Faris, B.F.

1960-04-01

155

Dehydration of plutonium trichloride hydrate  

DOEpatents

A process of 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 is provided.

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

1991-12-31

156

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

Microsoft Academic Search

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

2002-01-01

157

PLUTONIUM CARRIER METATHESIS WITH ORGANIC REAGENT  

DOEpatents

A method is described for converting a plutonium containing bismuth phosphate carrier precipitate Into a compositton more readily soluble in acid. The method consists of dissolving the bismuth phosphate precipitate in an aqueous solution of alkali metal hydroxide, and adding one of a certaia group of organic compounds, e.g., polyhydric alcohols or a-hydrorycarboxylic acids. The mixture is then heated causiing formation of a bismuth hydroxide precipitate containing plutonium which may be readily dissolved in nitric acid for further processing.

Thompson, S.G.

1958-07-01

158

The Extraction of Selected Transplutonium(III) and Lanthanide(III) Ions by Dihexyl-N, N-diethylcarbamoylmethylphosphonate from Aqueous Nitrate Media  

Microsoft Academic Search

The extraction behavior of selected transplutonium(III) and lanthanide(III) ions fromnitrate solution was studied using relatively pure dihexyl-N, N-diethyl-carbamoylmethylphosphonate (DHDECMP). The data obtained for Am(III) and Eu(III) using DHDECMP were compared with analogous measurements obtained with dibutyl butylphosphonate (DB[BP]) and in certain cases with dihexyl-N, N-diethylcarbamoylethylphosphonate (DHDECEP). It was found that both the nitrate and extractant concentration dependencies were third power.

E. P. Horwitz; A. C. Muscatello; D. G. Kalina; L. Kaplan

1981-01-01

159

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

160

Thermal Decomposition of Nitrated Tributyl Phosphate.  

National Technical Information Service (NTIS)

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 ...

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

1995-01-01

161

Modeling of the Extraction of Nitric Acid and Neodymium Nitrate from Aqueous Solutions over a Wide Range of Activities by CMPO  

Microsoft Academic Search

A thermodynamic model that allows one to determine the number and the stoichiometry of the complexes formed between nitric acid, neodymium nitrate (Nd(NO3)3), and octyl(phenyl)?N,N?diisobutylcarbamoylmethyl phosphine oxide (CMPO) diluted in nitrophenylhexyl ether (NPHE) also called 1?(hexyloxy)?2?nitrobenzene, is presented in this work. The Mikulin?Sergievskii?Dannus' model was used to model the extraction at 25°C of the HNO3?H2O?NPHE, HNO3?H2O?CMPO 0.2 mol kg?NPHE, Nd(NO3)3?H2O?CMPO 0.2 mol kg?NPHE and

S. Belair; A. Labet; C. Mariet; P. Dannus

2005-01-01

162

METHOD FOR SEPARATING PLUTONIUM AND FISSION PRODUCTS EMPLOYING AN OXIDE AS A CARRIER FOR FISSION PRODUCTS  

DOEpatents

Carrier precipitation processes for separating plutonium values from uranium fission products are described. Silicon dioxide or titanium dioxide in a finely divided state is added to an acidic aqueous solution containing hexavalent plutonium ions together with ions of uranium fission products. The supernatant solution containing plutonium ions is then separated from the oxide and the fission products associated therewith.

Davies, T.H.

1961-07-18

163

PROCESS USING POTASSIUM LANTHANUM SULFATE FOR FORMING A CARRIER PRECIPITATE FOR PLUTONIUM VALUES  

DOEpatents

A process is presented for recovering plutonium values in an oxidation state not greater than +4 from fluoride-soluble fission products. The process consists of adding to an aqueous acidic solution of such plutonium values a crystalline potassium lanthanum sulfate precipitate which carries the plutonium values from the solution.

Angerman, A.A.

1958-10-21

164

PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS  

DOEpatents

S>A method is described for separating plutonium, in a valence state of less than five, from an aqueous solution in which it is dissolved. The niethod consists in adding potassium and sulfate ions to such a solution while maintaining the solution at a pH of less than 7.1, and isolating the precipitate of potassium plutonium sulfate thus formed.

Duffield, R.B.

1959-02-24

165

Plutonium Predominance Region Diagrams.  

National Technical Information Service (NTIS)

Four plutonium predominance region diagrams, a technique for estimating the solubility of hydrous plutonium(IV) oxide, and a method for comparing valence state distributions of uranium, neptunium and plutonium are described.

G. L. Silver

1975-01-01

166

Recovery of Plutonium from Electrorefining Anode Heels at Savannah River.  

National Technical Information Service (NTIS)

In a joint effort, the Savannah River Laboratory (SRL), Savannah River Plant (SRP), and the Rocky Flats Plant (RFP) have developed two processes to recover plutonium from electrorefining anode heel residues. Aqueous dissolution of anode heel metal was dem...

J. H. Gray L. W. Gray D. G. Karraker

1987-01-01

167

Plutonium story  

SciTech Connect

The first nuclear synthesis and identification (i.e., the discovery) of the synthetic transuranium element plutonium (isotope /sup 238/Pu) and the demonstration of its fissionability with slow neutrons (isotope /sup 239/Pu) took place at the University of California, Berkeley, through the use of the 60-inch and 37-inch cyclotrons, in late 1940 and early 1941. This led to the development of industrial scale methods in secret work centered at the University of Chicago's Metallurgical Laboratory and the application of these methods to industrial scale production, at manufacturing plants in Tennessee and Washington, during the World War II years 1942 to 1945. The chemical properties of plutonium, needed to devise the procedures for its industrial scale production, were studied by tracer and ultramicrochemical methods during this period on an extraordinarily urgent basis. This work, and subsequent investigations on a worldwide basis, have made the properties of plutonium very well known. Its well studied electronic structure and chemical properties give it a very interesting position in the actinide series of inner transition elements.

Seaborg, G T

1981-09-01

168

Oxiconazole Nitrate  

Center for Drug Evaluation (CDER)

Text Version... Draft Guidance on Oxiconazole Nitrate This draft guidance, once finalized, will represent the Food and Drug Administration's (FDA's) current ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

169

FLAME DENITRATION AND REDUCTION OF URANIUM NITRATE TO URANIUM DIOXIDE  

DOEpatents

A process is given for converting uranyl nitrate solution to uranium dioxide. The process comprises spraying fine droplets of aqueous uranyl nitrate solution into a hightemperature hydrocarbon flame, said flame being deficient in oxygen approximately 30%, retaining the feed in the flame for a sufficient length of time to reduce the nitrate to the dioxide, and recovering uranium dioxide. (AEC)

Hedley, W.H.; Roehrs, R.J.; Henderson, C.M.

1962-06-26

170

METHOD FOR DISSOLVING LANTHANUM FLUORIDE CARRIER FOR PLUTONIUM  

DOEpatents

A method is described for dissolving lanthanum fluoride precipitates which is applicable to lanthanum fluoride carrier precipitation processes for recovery of plutonium values from aqueous solutions. The lanthanum fluoride precipitate is contacted with an aqueous acidic solution containing dissolved zirconium in the tetravalent oxidation state. The presence of the zirconium increases the lanthanum fluoride dissolved and makes any tetravalent plutonium present more readily oxidizable to the hexavalent state. (AEC)

Koshland, D.E. Jr.; Willard, J.E.

1961-08-01

171

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

172

Theoretical study of the structural properties of plutonium(IV) and (VI) complexes.  

PubMed

The structural properties of several plutonium(IV) and (VI) complexes have been examined in the gaseous and aqueous phases using Kohn-Sham density functional theory calculations with scalar relativistic effective core potentials and the polarizable continuum solvation model. The aquo and nitrate complexes of PuO(2)(2+) and Pu(4+) were considered in addition to the aquo-chloro complexes of PuO(2)(2+). The nitrate and chloro- complexes formed with triphenylphosphine oxide (TPPO) and tributylphosphate (TBP) respectively were also studied. The structural parameters of the plutonyl complexes were compared to their uranyl and neptunyl analogues. The bond lengths and vibrational frequencies of the plutonyl complexes can generally be computed with sufficient accuracy with the pure PBE density functional with shorter bond lengths being predicted by the B3LYP functional. The structural parameters of the [PuO(2)Cl(2)L(2)] systems formed with TPPO and TBP as well as the aqueous [PuO(2)Cl(2)(H(2)O)(3)] complex are matched to previous experimental results. Overall, the inclusion of ligands in the equatorial region results in significant changes in the stretching frequency of the plutonyl group. The structural features of the plutonyl (VI) systems are rather similar to those of their 5f(0) uranyl and 5f(1) neptunyl counterparts. For the Pu(IV) aquo and nitrate complexes, the average of the calculated Pu-OH(2) and Pu-O(nitrate) bond lengths are generally within 0.04 Å of the reported experimental values. Overall Kohn-Sham DFT can be used successfully in predicting the structures of this diverse set of Pu(VI) and Pu(IV) complexes. PMID:22040181

Odoh, Samuel O; Schreckenbach, Georg

2011-11-11

173

Simulation development for Silo Test Program (STP). Volume 2. Detonation characterization of NA/NP (aqueous nitric acid/nitropropane) and NPN (nitropropane nitrate). Technical report, 11 January 1982-31 March 1984  

SciTech Connect

In support of the Defense Nuclear Agency (DNA) Silo Test Program, the planar steady detonation processes were characterized and initial JWL (Jones-Wilkins-Lee) equation of state (EOS) coefficients were developed for two chemical high explosives (HEs), NA/NP and NPN. NA/NP is a liquid explosive composed of weak (Baume 42) aqueous nitric acid (NA) and the solvent nitropropane (NP). The NA/NP studied here was 3.158 parts NA to 1 part NP, by weight, and its density was 1.25 Mg/m cubed at 29/sup 0/C. NPN (nitropropane nitrate) is a damp granulated blasting agent composed of ammonium nitrate (AN), NP, and methyl alcohol (MA). The study material was 0.848 AN, 0.075 NP, 0.075 MA, and 0.002 methocel (an added antimigratory agent), by weight, and had a density of 1.01 Mg/m cubed. These unusual explosives are being considered by DNA for use in various nuclear weapons effects simulators because of their potential for producing desired pulse shapes at competitive costs. SRI large-scale multiple Lagrange particle-velocity gage experiments, in combination with Lagrange analyses, quantified the early stages of the steady planar detonation process in each material. Thermodynamic equilibrium calculations, performed with the SRI TIGER code, extended the adiabatic release paths to pressures approaching atmospheric. NA/NP exhibited ideal detonation with a pressure-relative volume (p-V) adiabatic release path slightly above that of nitromethane (NM) and a resolved reaction zone of surprisingly long duration, 0.2-0.6 microsecs.

Rosenberg, J.T.; Erlich, D.C.; Keough, D.D.

1984-03-31

174

IMPROVED PROCESS OF PLUTONIUM CARRIER PRECIPITATION  

DOEpatents

This patent relates to an improvement in the bismuth phosphate process for separating and recovering plutonium from neutron irradiated uranium, resulting in improved decontamination even without the use of scavenging precipitates in the by-product precipitation step and subsequently more complete recovery of the plutonium in the product precipitation step. This improvement is achieved by addition of fluomolybdic acid, or a water soluble fluomolybdate, such as the ammonium, sodium, or potassium salt thereof, to the aqueous nitric acid solution containing tetravalent plutonium ions and contaminating fission products, so as to establish a fluomolybdate ion concentration of about 0.05 M. The solution is then treated to form the bismuth phosphate plutonium carrying precipitate.

Faris, B.F.

1959-06-30

175

Plutonium and security  

Microsoft Academic Search

Plutonium and Security discusses the cases for and against the reprocessing of spent reactor fuel elements to remove the plutonium from them. The relationship between the capability to produce plutonium and the proliferation of nuclear weapons to countries that do not already have them is discussed. America's policy for the civil use of plutonium and its policy to prevent the

Barnaby

1992-01-01

176

Preparation of acid standards for and determination of free acid in concentrated plutonium-uranium solutions  

SciTech Connect

Standard nitric acid solutions containing up to 400 g/L plutonium and/or uranium were prepared and these provide a way of rigorously testing methods for the determination of free acid in concentrated plutonium solutions. These standard solutions were prepared from uranyl nitrate hexahydrate and crystalline plutonium(IV) nitrate which was in turn obtained by vacuum evaporation of nitric acid solutions of Pu(IV). Three methods of free acid determination in plutonium solutions were tested, and the widely accepted iodate precipitation methods was shown to give markedly erroneous results at high plutonium concentrations. An improved oxalate complexing procedure was developed which gives accurate results (bias less than the standard deviation of 0.02 M) up to at least 400 g/L plutonium. 27 references, 2 figures, 2 tables.

Ryan, J.L.; Bryan, G.H.; Burt, M.C.; Costanzo, D.A.

1985-06-01

177

RECOVERY OF PLUTONIUM BY CARRIER PRECIPITATION  

DOEpatents

The recovery of plutonium from an aqueous nitric acid Zr-containing solution of 0.2 to 1N acidity is accomplished by adding fluoride anions (1.5 to 5 mg/l), and precipitating the Pu with an excess of H/sub 2/0/sub 2/ at 53 to 65 deg C. (AEC)

Goeckermann, R.H.

1961-04-01

178

Continuous plutonium(IV) oxalate precipitation, filtration, and calcination process. [From product streams from Redox, Purex, or Recuplex solvent extraction plants  

Microsoft Academic Search

A continuous plutonium (IV) oxalate precipitation, filtration, and calcination process has been developed. Continuous and batch decomposition of the oxalate in the filtrates has been demonstrated. The processes have been demonstrated in prototype equipment. Plutonium (IV) oxalate was precipitated continuously at room temperature by the concurrent addition of plutonium (IV) nitrate feed and oxalic acid into the pan of a

Beede

1956-01-01

179

DEVELOPMENT OF PLUTONIUM BEARING FUEL MATERIALS. Monthly Progress Letter for November 1961  

Microsoft Academic Search

Major effort ls reported on chemical processing and product ; characterization. Material recycle problems were investigated by conducting ; oxalate precipitations from dilute plutonium nitrate solutions. PuOâ was ; also prepared via the plutonium peroxide route. Continued studies are also ; reported on UOâ- PuOâ coprecipitation, powder characterizatlon, and ; coating techniques for deposition of Ni and Cu on PuO\\/subn

Puechi

1961-01-01

180

PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS  

DOEpatents

This patent relates to an improved method for the decontamination of plutonium. The process consists broadly in an improvement in a method for recovering plutonium from radioactive uranium fission products in aqueous solutions by decontamination steps including byproduct carrier precipitation comprising the step of introducing a preformed aqueous slurry of a hydroxide of a metal of group IV B into any aqueous acidic solution which contains the plutonium in the hexavalent state, radioactive uranium fission products contaminant and a by-product carrier precipitate and separating the metal hydroxide and by-product precipitate from the solution. The process of this invention is especially useful in the separation of plutonium from radioactive zirconium and columbium fission products.

Sutton, J.B.

1958-02-18

181

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

182

[N(n-Bu)4]2[Pu(NO3)6] and [N(n-Bu)4]2[PuCl6]: starting materials to facilitate nonaqueous plutonium(IV) chemistry.  

PubMed

The reaction of plutonium(IV) in aqueous nitric acid with tetra-n-butylammonium nitrate leads to the immediate precipitation of [N(n-Bu)(4)](2)[Pu(NO(3))(6)] (1) in high yield. The analogous reaction in HCl with tetra-n-butylammonium chloride gives [N(n-Bu)(4)](2)[PuCl(6)] (2). Both 1 and 2 are soluble in a range of organic solvents and have been characterized by single-crystal X-ray diffraction, IR spectroscopy, and solid- and solution-phase vis-near-IR spectroscopy. 1 and 2 provide facile synthetic entry routes to study plutonium(IV) ligand complexation reactions in organic solvent media under both air/moisture-stable and -sensitive conditions. PMID:22900742

Reilly, Sean D; Scott, Brian L; Gaunt, Andrew J

2012-08-17

183

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

184

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

185

21 CFR 181.33 - Sodium nitrate and potassium nitrate.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Sodium nitrate and potassium nitrate. 181.33...Prior-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are...

2013-04-01

186

Plutonium Immobilization Canister Loading.  

National Technical Information Service (NTIS)

This disposition of excess plutonium is determined by the Surplus Plutonium Disposition Environmental Impact Statement (SPD-EIS) being prepared by the Department of Energy. The disposition method (Known as 'can in canister') combines cans of immobilized p...

E. L. Hamilton

1999-01-01

187

METHOD OF SEPARATING PLUTONIUM  

DOEpatents

Plutonium hexafluoride is a satisfactory fluorinating agent and may be reacted with various materials capable of forming fluorides, such as copper, iron, zinc, etc., with consequent formation of the metal fluoride and reduction of the plutonium to the form of a lower fluoride. In accordance with the present invention, it has been found that the reactivity of plutonium hexafluoride with other fluoridizable materials is so great that the process may be used as a method of separating plutonium from mixures containing plutonium hexafluoride and other vaporized fluorides even though the plutonium is present in but minute quantities. This process may be carried out by treating a mixture of fluoride vapors comprising plutonium hexafluoride and fluoride of uranium to selectively reduce the plutonium hexafluoride and convert it to a less volatile fluoride, and then recovering said less volatile fluoride from the vapor by condensation.

Brown, H.S.; Hill, O.F.

1958-02-01

188

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

189

PREPARATION OF PLUTONIUM TRIFLUORIDE  

DOEpatents

A process of producing plutonium trifluoride by reacting dry plutonium(IV) oxalate with chlorofluorinated methane or ethane at 400 to 450 deg C and cooling the product in the absence of oxygen is described.

Burger, L.L.; Roake, W.E.

1961-07-11

190

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

191

Plutonium immobilization -- Can loading  

Microsoft Academic Search

The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP adds the excess plutonium to ceramic pucks, loads the pucks into cans, and places the cans into DWPF canisters. This paper discusses the PIP process steps, the can loading conceptual design, can loading equipment design, and can loading work completed.

Kriikku

2000-01-01

192

PLUTONIUM-ZIRCONIUM ALLOYS  

Microsoft Academic Search

A series of nuclear reactor fuel alloys consisting of from about 5 to ; about 50 at.% zirconium (or higher zirconium alloys such as Zircaloy), balance ; plutonium, and having the structural composition of a plutonium are described. ; Zirconium is a satisfactory diluent because it alloys readily with plutonium and ; has desirable nuclear properties. Additional advantages are corrosion

F. W. Schonfeld; J. T. Waber

1960-01-01

193

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

194

Safety Studies to Measure Exothermic Reactions of Spent Plutonium Decontamination Chemicals Using Wet and Dry Decontamination Methods.  

National Technical Information Service (NTIS)

The Plutonium Finishing Plant (PFP) at the Hanford site in Eastern Washington is currently being decommissioned by Fluor Hanford. Chemicals being considered for dccontamination of gloveboxes in PFP include cerium (IV) nitrate in a nitric acid solution, an...

A. M. Hopkins T. D. Cooper J. R. Ewalt G. W. Jackson M. J. Minette S. L. Charboneau R. D. Scheele S. A. Jones P. A. Scott

2005-01-01

195

Plutonium-238 in fallout.  

PubMed

The observed variation in the activity ratio of plutonium-238 to plutonium-239 plus plutonium-240 in rainwater in Japan over the period from 1961 through 1968 seems to indicate that the influence of the plutonium-238 released by the burnup of the nuclear auxiliary power generator (SNAP-9A) became noticeable within about 6 months and that variation in the isotope ratio with time is affected by nuclear debris produced in the latest explosions as well as by the plutonium-238 released from the SNAP-9A generator. PMID:4883465

Mamuro, T; Matsunami, T

1969-01-31

196

33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...  

Code of Federal Regulations, 2010 CFR

...ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...contamination such as flammable liquids, combustible liquids,...

2010-07-01

197

33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...  

Code of Federal Regulations, 2010 CFR

...ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...contamination such as flammable liquids, combustible liquids,...

2009-07-01

198

BASIC PEROXIDE PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINANTS  

DOEpatents

A process is described for the separation from each other of uranyl values, tetravalent plutonium values and fission products contained in an aqueous acidic solution. First the pH of the solution is adjusted to between 2.5 and 8 and hydrogen peroxide is then added to the solution causing precipitation of uranium peroxide which carries any plutonium values present, while the fission products remain in solution. Separation of the uranium and plutonium values is then effected by dissolving the peroxide precipitate in an acidic solution and incorporating a second carrier precipitate, selective for plutonium. The plutonium values are thus carried from the solution while the uranium remains flissolved. The second carrier precipitate may be selected from among the group consisting of rare earth fluorides, and oxalates, zirconium phosphate, and bismuth lihosphate.

Seaborg, G.T.; Perlman, I.

1959-02-10

199

THE PREPARATION OF PLUTONIUM-ALUMINUM AND OTHER PLUTONIUM ALLOYS  

Microsoft Academic Search

The preparation of plutonium-aluminum alloys by the direct reduction of plutonium trifluoride and plutonium dioxide is described. Plutonium trifluoride is reduced more rapidly at 800 deg C than at 1125 deg C with liquid aluminum owing to the evolution of gaseous aluminum monofluoride at the lower temperature. Plutonium dioxide is reduced readily by an excess of liquid aluminum at 1200

Runnalls; O. J. C

1958-01-01

200

Separation and recovery of plutonium from oxalate supernatant using CMPO  

SciTech Connect

A simple and efficient procedure has been developed to quantitatively recover Pu from oxalate supernatant using a mixture of octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and TBP in dodecane. Pu(IV) in the range of 6.9 to 34.6 mg/l was quantitatively extracted into 0.2M CMPO + 1.2 M TBP in dodecane from an aqueous solution containing 3.0 M HNO[sub 3] and 0.1 M H[sub 2]C[sub 2]O[sub 4]. At such low concentrations of Pu, the distribution ratio (D) did not change but the increase in oxalic acid concentration drastically reduced these values. The variation in HNO[sub 3] concentration at a fixed concentration of 0.2 M CMPO + U 1.2 M TBP has shown a dramatic increase in the D values, being 0.3 at 1.0 M and >10[sup 4] at 7.5 M. The extraction was almost quantitative even at the aqueous-to-organic ratio of 10:1. Plutonium could be quantitatively recovered by (i) stripping with 0.5 M acetic acid and (ii) coprecipitating it directly from the organic phase with 0.3 M oxalic acid + 0.3 M calcium nitrate + sodium nitrite. [approximately] 92% of the Pu was found in the precipitate and [approximately] 7% in the supernant. Using this procedure, Pu in a concentrated form ([approximately] 50 times) could be recovered from the oxalate supernatant solutions without recourse to the destruction of oxalate ion. 19 refs., 5 figs., 5 tabs.

Mathur, J.N.; Murali, M.S.; Rizvi, G.H.; Iyer, R.H.; Michael, K.M.; Kapoor, S.C.; Dhumwad, R.K.; Badheka, L.P.; Banerji, A. (Bhabha Atomic Research Centre, Trombay (India))

1994-08-01

201

Insensitive Ammonium Nitrate.  

National Technical Information Service (NTIS)

The danger of the accidental detonation of large masses of commercial ammonium nitrate during handling and storage under normal climatic conditions is reduced by replacing the ammonium nitrate with a solid solution of potassium nitrate in form III ammoniu...

C. Boyars

1978-01-01

202

METHOD OF SEPARATING PLUTONIUM FROM LANTHANUM FLUORIDE CARRIER  

DOEpatents

An improvement in oxidation-reduction type methods of separating plutoniunn from elements associated with it in a neutron-irradiated uranium solution is described. The method relates to the separating of plutonium from lanthanum ions in an aqueous 0.5 to 2.5 N nitric acid solution by 'treating the solution, at room temperature, with ammonium sulfite in an amount sufficient to reduce the hexavalent plutonium present to a lower valence state, and then treating the solution with H/sub 2/O/sub 2/ thereby forming a tetravalent plutonium peroxide precipitate.

Watt, G.W.; Goeckermann, R.H.

1958-06-10

203

Destruction of nitrates, organics, and ferrocyanides by hydrothermal processing.  

National Technical Information Service (NTIS)

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 compone...

J. M. Robinson B. R. Foy P. C. Dell'Orco G. Anderson F. Archuleta

1993-01-01

204

Method for improved decomposition of metal nitrate solutions  

DOEpatents

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

Haas, Paul A. (Knoxville, TN); Stines, William B. (Knoxville, TN)

1983-10-11

205

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

206

Evaluation of nitrate and nitrite destruction/separation technologies  

SciTech Connect

This report describes and evaluates four types of nitrate and nitrite destruction and separation technologies that could be used to treat the aqueous, alkaline, nitrate-bearing mixed waste that is generated by the In-Tank Precipitation (ITP) process at the Savannah River Site (SRS). The technologies considered in this report include thermal, hydrothermal, chemical, and electrochemical technologies.

Hobbs, D.T.

1997-08-29

207

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

208

Pyrochemical processing of plutonium. Technology review report  

Microsoft Academic Search

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 PuOâ batch size

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

1982-01-01

209

Evaluation of the Magnesium Hydroxide Treatment Process for Stabilizing PFP Plutonium/Nitric Acid Solutions  

SciTech Connect

This document summarizes an evaluation of the magnesium hydroxide [Mg(OH)2] process to be used at the Hanford Plutonium Finishing Plant (PFP) for stabilizing plutonium/nitric acid solutions to meet the goal of stabilizing the plutonium in an oxide form suitable for storage under DOE-STD-3013-99. During the treatment process, nitric acid solutions bearing plutonium nitrate are neutralized with Mg(OH)2 in an air sparge reactor. The resulting slurry, containing plutonium hydroxide, is filtered and calcined. The process evaluation included a literature review and extensive laboratory- and bench-scale testing. The testing was conducted using cerium as a surrogate for plutonium to identify and quantify the effects of key processing variables on processing time (primarily neutralization and filtration time) and calcined product properties.

Gerber, Mark A.; Schmidt, Andrew J.; Delegard, Calvin H.; Silvers, Kurt L.; Baker, Aaron B.; Gano, Susan R.; Thornton, Brenda M.

2000-09-28

210

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

211

SEPARATION OF FISSION PRODUCT VALUES FROM THE HEXAVALENT PLUTONIUM BY CARRIER PRECIPITATION  

DOEpatents

An improved precipitation of fission products on bismuth phosphate from an aqueous mineral acid solution also containing hexavalent plutonium by incorporating, prior to bismuth phosphate precipitation, from 0.05 to 2.5 grams/ liter of zirconium phosphate, niobium oxide. and/or lanthanum fluoride is described. The plutonium remains in solution.

Davies, T.H.

1959-12-15

212

Plutonium Accident Resistant Container Project.  

National Technical Information Service (NTIS)

The PARC (plutonium accident resistant container) project resulted in the design, development, and certification testing of a crashworthy air-transportable plutonium package (shipping container) for certification by the USNRC. This PAT-1 (plutonium air tr...

J. A. Andersen

1978-01-01

213

Water Activities, Osmotic and Activity Coefficients and Some Correlation of Aqueous Mixtures of Alkaline-Earth and Ammonium Nitrates, NH 4 NO 3 -Y(NO 3 ) 2 -H 2 O with Y ? Ba 2+ , Mg 2+ and Ca 2+ at T = 25?°C  

Microsoft Academic Search

The thermodynamic properties of the mixed aqueous electrolyte of ammonium and alkaline earth metal nitrates have been studied\\u000a using the hygrometric method at 25??C. The water activities of these {yNH4NO3+(1?y)Y(NO3)2}(aq) systems with Y ? Ba2+, Mg2+ and Ca2+ were measured at total molalities ranging from 0.10 mol?kg?1 to saturation for different NH4NO3 ionic-strength fractions of y=0.20, 0.50 and 0.80. These

Mohamed Marouani

2007-01-01

214

Plutonium Immobilization Canister Loading  

Microsoft Academic Search

This disposition of excess plutonium is determined by the Surplus Plutonium Disposition Environmental Impact Statement (SPD-EIS) being prepared by the Department of Energy. The disposition method (Known as ''can in canister'') combines cans of immobilized plutonium-ceramic disks (pucks) with vitrified high-level waste produced at the SRS Defense Waste Processing Facility (DWPF). This is intended to deter proliferation by making the

1999-01-01

215

North Korean Plutonium Production  

Microsoft Academic Search

In 1992, as part of its obligations under the Nuclear Non?Proliferation Treaty, North Korea declared that it had earlier separated abut 100 grams of plutonium from damaged fuel rods removed from a 25 megawatt?thermal (MWt) gas?graphite reactor at Yongbyon. The plutonium was separated at the nearby “Radiochemical Laboratory.” Separated plutonium is the raw ingredient for making nuclear weapons, but 100

David Albright

1994-01-01

216

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

217

PREPARATION OF PLUTONIUM  

DOEpatents

Methods are presented for the electro-deposition of plutonium from fused mixtures of plutonium halides and halides of the alkali metals and alkaline earth metals. Th salts, preferably chlorides and with the plutonium prefer ably in the trivalent state, are placed in a refractory crucible such as tantalum or molybdenam and heated in a non-oxidizing atmosphere to 600 to 850 deg C, the higher temperatatures being used to obtain massive plutonium and the lower for the powder form. Electrodes of graphite or non reactive refractory metals are used, the crucible serving the cathode in one apparatus described in the patent.

Kolodney, M.

1959-07-01

218

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

219

Paliperidonium nitrate  

PubMed Central

In the title mol­ecular salt (systematic name: 3-{2-[4-(6-fluoro-1,2-benzoxazol-3-yl)piperidin-1-yl]eth­yl}-9-hy­droxy-2-methyl-1,6,7,8,9,9a-hexa­hydro­pyrido[1,2-a]pyrimidin-4-one nitrate), C23H29FN4O3 +·NO3 ?, the piperidine ring displays a chair conformation and its N atom is protonated; the N—H bond is in an axial orientation. The ring bearing the hy­droxy group exhibits a half-chair conformation. The hy­droxy group as well as the adjacent methyl­ene group are disordered over two sets of sites in a 0.823?(5):0.177?(5) ratio. In the crystal, O—H?N, O—H?O, N—H?O and N—H?N hydrogen bonds connect the components into a three-dimensional network.

Ge, Jingshui; Luo, Yang-Hui

2012-01-01

220

Effects of various moderators on the critical mass of plutonium  

SciTech Connect

The fissile material storage tanks in the Hanford Plutonium Critical Mass Laboratory (CML) in Richland, Washington, are presently being upgraded. During the design and planning phase of this modification, criticality analysis was necessary to compare potential moderator/absorber materials used as isolators between tanks. A parameter study was performed to assist in determining the appropriate moderator material to be used in the plutonium nitrate storage tank system in the mix room at the CML. Four moderator/absorber materials were identified as providing adequate isolation between the tanks.

Doherty, A.L.

1986-01-01

221

Nitrate removal using natural clays modified by acid thermoactivation  

NASA Astrophysics Data System (ADS)

Groundwater pollution by nitrates is a widespread problem in many locations in the world. The underground aquatic mantle of the Peninsula of Yucatan is highly vulnerable due to its karstic nature. Adsorption methods are a good choice for nitrate elimination. In this work, a natural calcium bentonite was modified by acid thermoactivation with HCl and H2SO4, and tested as a media for nitrate removal in an aqueous solution. The nitrate concentration in the solution was measured by FT-IR, using the Lambert Beer law. Clay characterization was carried out by X-ray diffraction and FT-IR spectroscopy; surface area was measured by the BET method.

Mena-Duran, C. J.; Sun Kou, M. R.; Lopez, T.; Azamar-Barrios, J. A.; Aguilar, D. H.; Domínguez, M. I.; Odriozola, J. A.; Quintana, P.

2007-04-01

222

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

223

MOLTEN PLUTONIUM PUMP EXPERIMENT  

Microsoft Academic Search

The Molten Plutonium Pump Experiment was a subcritical mock-up of a ; reactor core in which a plutonium-iron alloy was circulated by means of a sodium ; lift pump. Sodium for the lift pumping was circulated by an E. M. pump in an ; isothermal loop at 500 deg C. The purpose of the test was to study pump ;

J. E. Deverall; G. L. Caldwell

1962-01-01

224

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

225

Plutonium and security  

SciTech Connect

Plutonium and Security discusses the cases for and against the reprocessing of spent reactor fuel elements to remove the plutonium from them. The relationship between the capability to produce plutonium and the proliferation of nuclear weapons to countries that do not already have them is discussed. America's policy for the civil use of plutonium and its policy to prevent the spread of nuclear weapons are described. European and Japanese plans in the 1990s for plutonium are analyzed as are current nuclear programs in Third World countries. The problems that will be faces by the 1995 conference to discuss for how long to extend the Non-Proliferation Treaty are outlined and the prospects for the conference analyzed. A global program for controlling fissile material is discussed in detail.

Barnaby, F. (University Coll., London (United Kingdom))

1992-01-01

226

Plutonium Immobilization Canister Loading  

SciTech Connect

This disposition of excess plutonium is determined by the Surplus Plutonium Disposition Environmental Impact Statement (SPD-EIS) being prepared by the Department of Energy. The disposition method (Known as ''can in canister'') combines cans of immobilized plutonium-ceramic disks (pucks) with vitrified high-level waste produced at the SRS Defense Waste Processing Facility (DWPF). This is intended to deter proliferation by making the plutonium unattractive for recovery or theft. The envisioned process remotely installs cans containing plutonium-ceramic pucks into storage magazines. Magazines are then remotely loaded into the DWPF canister through the canister neck with a robotic arm and locked into a storage rack inside the canister, which holds seven magazines. Finally, the canister is processed through DWPF and filled with high-level waste glass, thereby surrounding the product cans. This paper covers magazine and rack development and canister loading concepts.

Hamilton, E.L.

1999-01-26

227

Method for dissolving plutonium dioxide  

DOEpatents

The fluoride-catalyzed, non-oxidative dissolution of plutonium dioxide in HNO.sub.3 is significantly enhanced in rate by oxidizing dissolved plutonium ions. It is believed that the oxidation of dissolved plutonium releases fluoride ions from a soluble plutonium-fluoride complex for further catalytic action.

Tallent, Othar K. (Oak Ridge, TN)

1978-01-01

228

THE FLUORINATION OF PLUTONIUM TETRAFLUORIDE  

Microsoft Academic Search

The fluorination of plutonium tetrafluoride by elemental fluorine to ; form plutonium hexafluoride was studied in a flow system at temperatures between ; 100 and 500 deg C. Partial pressures of fluorine from 0.25 to 1.0 atmosphere were ; used. The plutonium tetrafluoride was obtained from several sources, including ; the dissolution of uranium-plutonium alloys in bromine trifluoride. Activation ;

M. J. Steindler; D. V. Steidl; R. K. Steunenberg

1958-01-01

229

PREPARATION OF DIBASIC ALUMINUM NITRATE  

DOEpatents

A method is given for the preparation and recovery of basic aluminum nltrates having an OH: Al ratio of at least two, comprising two steps. First, metallic aluminum is dissolved in aqueous Al(NO/sub 3/)/sub 3/, in the presence of a small quantity of elemental or ionic mercury, to increase its Al: NO/sub 3/ ratio into the range 1 to 1.2. The resulting aqueous solution is then added to an excess of a special organic solvent, typically a mixture of five parts methanol and six parts diethyl ether, whereupon the basic aluminum nitrate, e.g. Al/sub 6/(OH)/sub 13/-(NO/sub 3/)/sub 5/, recoverably precipitates.

Gresky, A.T.; Nurmi, E.O.; Foster, D.L.; Wischow, R.P.; Savolainen, J.E.

1960-04-01

230

Formation of a third phase in the simultaneous extraction of actinide(IV) and uranyl nitrates by tributyl phosphate in dodecane  

SciTech Connect

The loading of a 30 vol.% solution of tributyl phosphate in dodecane with large amounts of thorium(IV), uranium(IV) or plutonium(IV) nitrate in the presence of uranyl nitrate causes the formation of a second organic phase, which contains both the actinide(IV) and uranium(VI). The presence of uranium(VI) in the third phase is due to physical distribution of uranyl nitrate, solvated by tributyl phosphate, between the two organic phases. Equations are suggested which describe the distribution of some components between the organic phases, and the actinide(IV) to uranium(VI) ratio in the second organic phase. The maximum attainable concentration of actinides(IV) in the organic phase of a two-liquid-phase system, at which a third phase is not yet formed, was measured and described by an empirical equation as a function of the concentration of uranium(VI) in the organic phase and of ntiric acid in the aqueous phase. 4 figures, 3 tables.

Nakashima, T.; Kolarik, Z.

1983-01-01

231

A portable concentrator for processing plutonium containing solutions  

SciTech Connect

This report describes a horizontal, compact agitated-film concentrator called a Rototherm, manufactured by Artisan Industries, Inc. which can be used to process aqueous solutions of radioactive wastes containing plutonium. The unit is designed to concentrate liquid streams to a high-solid content slurry.

Chamberlain, D.B.; Conner, C.; Chen, L. [and others

1995-12-01

232

METHOD OF SEPARATING PLUTONIUM FROM LANTHANUM FLUORIDE CARRIER  

Microsoft Academic Search

An improvement in oxidation-reduction type methods of separating ; plutoniunn from elements associated with it in a neutron-irradiated uranium ; solution is described. The method relates to the separating of plutonium from ; lanthanum ions in an aqueous 0.5 to 2.5 N nitric acid solution by 'treating the ; solution, at room temperature, with ammonium sulfite in an amount sufficient

G. W. Watt; R. H. Goeckermann

1958-01-01

233

Treatment of human contamination with plutonium and americium: would orally administered Ca- or Zn-DTPA be effective?  

PubMed

Accidental or deliberate dispersion of plutonium (Pu) and americium (Am) into the public environment could contaminate large numbers of people by inhalation. If measures to reduce the internal dose are considered appropriate, oral administration of either calcium (Ca) or zinc (Zn) diethylenetriaminepenta-acetic acid (DTPA) would be the simplest treatment. Published experimental data from rats on the effects of oral DTPA on the retention of inhaled Pu and Am show that: (1) orally administered Zn-DTPA is as effective as repeated intravenous injection for the decorporation of Pu and Am inhaled as nitrates, although higher dosages are required; (2) oral Zn-DTPA appears to be an effective treatment for Am dioxide but not Pu dioxide; (3) maximum decorporation of Pu, by oral or intravenous administration, requires a large molar excess of Zn-DTPA over Pu (>1 x 10(6)); (4) neither oral nor injected Zn-DTPA are likely to be effective for Pu oxides, nor when Pu and Am nitrates are mixed with other dusts. It is concluded that oral administration of a simple aqueous solution of Zn-DTPA could be an important treatment in accident or emergency scenarios after intake of pure chemical forms of Pu and Am, which are highly or moderately soluble in biological fluids. However, more research is needed on the efficacy of treatment when these forms are mixed with other materials. Importantly, studies designed to increase the efficiency of uptake of DTPA from the gastrointestinal tract could appreciably reduce the dosage. PMID:17556346

Taylor, David M; Hodgson, Susan A; Stradling, Neil

2007-06-07

234

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

235

Nitrate Risk Management under Uncertainty.  

National Technical Information Service (NTIS)

In many areas throughout the U.S., groundwater supplies are contaminated by nitrates. Nitrate contamination has been a subject of concern because nitrate salt can induce infant methemoglobinemia and cancer. Nitrate risk management describes the process lu...

Y. W. Lee

1991-01-01

236

Alkyl nitrates and bifunctional nitrates of atmospheric interest: Henry's law constants and their temperature dependencies  

Microsoft Academic Search

Henry's law coefficients of 15 alkyl nitrates, keto-, hydroxy-, and dinitrates of atmospheric interest have been measured, mostly over the temperature range 1–25°C. The compounds are stable in aqueous solution. Where literature data were available, Henry's law coefficients are in very good agreement. It is concluded that dissolution in cloud and rain water is not an important loss process for

Jost Kames; Ulrich Schurath

1992-01-01

237

PLUTONIUM ELECTROREFINING CELLS  

DOEpatents

Electrorefining cells for obtaining 99.98% plutonium are described. The cells consist of an impure liquid plutonium anode, a molten PuCl/sub 3/-- alkali or alkaline earth metal chloanode, a molten PuCl/sub 3/-alkali or alkaline earth metal chloride electrolyte, and a nonreactive cathode, all being contained in nonreactive ceramic containers which separate anode from cathode by a short distance and define a gap for the collection of the purified liquid plutonium deposited on the cathode. Important features of these cells are the addition of stirrer blades on the anode lead and a large cathode surface to insure a low current density. (AEC)

Mullins, L.J. Jr.; Leary, J.A.; Bjorklund, C.W.; Maraman, W.J.

1963-07-16

238

Spectroscopy of plutonium-organic complexes  

SciTech Connect

Information on the spectroscopy of plutonium-organic complexes is needed to help establish the speciation of these complexes under environmentally relevant conditions. Laser photoacoustic spectroscopy (LPAS) and absorption spectrometry were used to characterize the Pu(IV)-citrate and Pu(IV)-nitrilotriacetic acid (NTA) complexes at concentrations of 10{sup {minus}3}--10{sup {minus}7} M in aqueous solution. Good agreement was observed between the band shape of the LPAS and absorption spectra for the Pu(IV)-NTA complex. Agreement for the Pu(IV)-citrate complex was not quite as good. In both cases, a linear dependence of the LPAS signal on laser power and total concentration of the complexes was noted. This work is part of an ongoing research effort to study key subsurface interactions of plutonium-organic complexes.

Richmann, M.K.; Reed, D.T.

1995-12-31

239

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

240

Plutonium dissolution process  

SciTech Connect

A two-step process is described 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 C and 70 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. 2 figs.

Vest, M.A.; Fink, S.D.; Karraker, D.G.; Moore, E.N.; Holcomb, H.P.

1996-01-09

241

Plutonium oxide dissolution  

Microsoft Academic Search

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

Gray

1992-01-01

242

Plutonium oxide dissolution  

Microsoft Academic Search

Several processing options for dissolving plutonium oxide (PuOâ) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuOâ typically generated by burning plutonium metal and PuOâ produced during incineration of alpha contaminated waste. At least two processing options remain applicable for dissolving high-fired PuOâ in canyon dissolvers. The options involve solid solution formation

Gray

1992-01-01

243

Shape-selected colloidal MOF crystals for aqueous use.  

PubMed

Methods are described to synthesize shape-selectable, monodisperse, aqueous-stable metal-organic frameworks (MOFs) by the reaction of aluminium nitrate with benzene tricarboxylic acid in various aqueous solvent mixtures and acetic acid as the capping ligand. Environmental stability was confirmed by thermal analysis and immersion in aqueous acidic media. PMID:24019122

Sindoro, Melinda; Jee, Ah-Young; Granick, Steve

2013-09-24

244

Investigations of plutonium immobilization into the vitreous compositions  

SciTech Connect

Disposal of radioactive waste is a central problem and among the most important concerns of the nuclear fuel cycle.The Russian concept of nuclear fuel-cycle management is aimed at reprocessing spent fuel with the maximum, economically justified extraction of useful components for their recycling. The technology currently used in Russia for reprocessing spent nuclear fuel gives rise to liquid high- level waste (HLW) with minor concentrations of valuable components such as uranium (U) and plutonium (Pu) [1]. The liquid radioactive wastes formed in the course of reprocessing are converted into the solid forms suitable for the transportation, storage, and burial. Of special importance is management of high-level waste (HLW). Although various technological approaches underlying the processes for the solidification or immobilization of liquid HLW are used at the research institutes of the MINATOM RF [1-5], all these approaches have in common the idea of a strong bonding of radionuclides in the resulting solid matrices. Therefore, development of solidification technologies must include the mandatory stages of investigating the behavior of HLW components during the immobilization process and in the prepared solidified compositions and characterizing their properties under conditions for subsequent transportation, storage, and burial. An important technological area of exploration is study of the behavior of long-lived alpha radionuclides during the course of the vitrification process and the ultimate long-range influence of these radionuclides on the properties of the immobilized forms. For the most part, immobilization of alpha radionuclides, particularly plutonium, in vitreous compositions involves investigations on the properties of final materials and the effect of alpha-decay radiation on the synthesized solid compositions. Another direction of investigation is study on the behavior of plutonium and transplutonium elements upon vitrification of liquid HLW, as applied to the one-stage process for immobilizing HLW by using different types of melters. Such studies were carried out to forecast the behavior of the above radionuclides during long-term operation of the ceramic melter at the vitrification facility of PU `Mayak.` The results of many investigations on the behavior of plutonium upon immobilization into phosphate and borosilicate vitreous compositions developed in Russia are generalized and summarized in the present work. In the conducted investigations of plutonium immobilization into both phosphate and borosilicate vitreous compositions used for the solidification of high-level liquid wastes upon vitrification in ceramic melters,0272 plutonium exhibited a limited solubility in the studied glass matrices. The solubility of plutonium, using plutonium dioxide powders, in phosphate and borosilicate glasses of specifically studied compositions was limited to 0.2 -0.4 wt %. The degree of incorporation (i.e., solubility) of plutonium, using plutonium in the form of nitrate solutions, in borosilicate glasses was also equal to 0.2-0.4 wt %. The degree of incorporation (i.e., solubility) of plutonium, using plutonium in the form of nitrate solutions, in phosphate glasses depended considerably on the chemical compositions of the solution to be solidified and on the specific glass matrix (i. e., on the composition of final solidified product) and was equal to 0.4-1.0 wt %. Available experimental data also allow one to assume that the use of the cold-crucible- induction melter (CCIM) method for immobilizing plutonium-containing wastes [6-8] provides a means of synthesizing the high-quality final solid-glass products with a plutonium content.

Matyunin, Y.I.; Jardine, L.J.

1998-03-02

245

RECOVERY OF TETRAVALENT CATIONS FROM AQUEOUS SOLUTIONS  

DOEpatents

The recovery of plutonium, zirconium, and tetravalent cerium values from aqueous solutions is described. It consists of adding an alkyl phosphate to a nnineral acid aqueous solution containing the metal to be recovered, whereby a precipitate forms with the tetravalent values, and separating the precipitate from the solution. All alkyl phosphates, if water-soluble, are suitable for the process; however, monobutyl phosphate has been found best.

Moore, R.L.

1958-05-01

246

Plutonium Ceramic Target for MASHA.  

National Technical Information Service (NTIS)

We are currently developing a plutonium ceramic target for the MASHA mass separator. The MASHA separator will use a thick plutonium ceramic target capable of tolerating temperatures up to 2000 degrees C. Promising candidates for the target include oxides ...

P. A. Wilk D. A. Shaughnessy K. J. Moody J. M. Kenneally

2004-01-01

247

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...

248

Preliminary Results from Plutonium\\/Americium Studies Using Simulated Savannah River Site Waste Solutions  

Microsoft Academic Search

To address the accelerated disposition of the supernate and salt portions of Savannah River Site, SRS, high level waste (HLW), solubility experiments were performed to develop a predictive capability for plutonium, Pu and americium , Am, solubility. Preliminary results from the experiments indicate hydroxide, OH-, carbonate, CO32-, nitrate, NO3-, and temperature are the predominant parameters affecting Pu and Am solubilities

2004-01-01

249

METHOD OF MAKING PLUTONIUM DIOXIDE  

DOEpatents

A process is presented For converting both trivalent and tetravalent plutonium oxalate to substantially pure plutonium dioxide. The plutonium oxalate is carefully dried in the temperature range of 130 to300DEC by raising the temperature gnadually throughout this range. The temperature is then raised to 600 C in the period of about 0.3 of an hour and held at this level for about the same length of time to obtain the plutonium dioxide.

Garner, C.S.

1959-01-13

250

Plutonium accident resistant container project  

Microsoft Academic Search

The PARC (plutonium accident resistant container) project resulted in the design, development, and certification testing of a crashworthy air-transportable plutonium package (shipping container) for certification by the USNRC. This PAT-1 (plutonium air transportable) package survives a very severe sequential test program of impact, crush, puncture, slash, burn, and water immersion. There is also an individual hydrostatic pressure test. The package

1978-01-01

251

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

252

Plutonium waste incineration using pyrohydrolysis  

Microsoft Academic Search

Waste generated by Savannah River Site (SRS) plutonium operations includes a contaminated organic waste stream. A conventional method for disposing of the organic waste stream and recovering the nuclear material is by incineration. When the organic material is burned, the plutonium remains in the incinerator ash. Plutonium recovery from incinerator ash is highly dependent on the maximum temperature to which

1991-01-01

253

PROCESS OF PRODUCING SHAPED PLUTONIUM  

Microsoft Academic Search

A process is presented for producing and casting high purity plutonium ; metal in one step from plutonium tetrafluoride. The process comprises heating a ; mixture of the plutonium tetrafluoride with calcium while the mixture is in ; contact with and defined as to shape by a material obtained by firing a mixture ; consisting of calcium oxide and from

Anicetti

1959-01-01

254

Plutonium storage: Requirements and challenges  

Microsoft Academic Search

The retirement of large numbers of nuclear weapons will necessitate management of unprecedented quantities of excess plutonium. In addition, surplus material and residues from previous weapon production activities comprise a substantial quantity of concentrated plutonium that exists in a variety of chemical forms. Storage of plutonium for an indefinite period will be necessary until a decision regarding ultimate disposition is

P. T. Cunningham; J. M. Haschke; J. C. Martz

1993-01-01

255

PLUTONIUM LOADING CAPACITY OF REILLEX HPQ ANION EXCHANGE COLUMN - AFS-2 PLUTONIUM FLOWSHEET FOR MOX  

SciTech Connect

Radioactive plutonium (Pu) anion exchange column experiments using scaled HB-Line designs were performed to investigate the dependence of column loading performance on the feed composition in the H-Canyon dissolution process for plutonium oxide (PuO{sub 2}) product shipped to the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). These loading experiments show that a representative feed solution containing {approx}5 g Pu/L can be loaded onto Reillex{trademark} HPQ resin from solutions containing 8 M total nitrate and 0.1 M KF provided that the F is complexed with Al to an [Al]/[F] molar ratio range of 1.5-2.0. Lower concentrations of total nitrate and [Al]/[F] molar ratios may still have acceptable performance but were not tested in this study. Loading and washing Pu losses should be relatively low (<1%) for resin loading of up to 60 g Pu/L. Loading above 60 g Pu/L resin is possible, but Pu wash losses will increase such that 10-20% of the additional Pu fed may not be retained by the resin as the resin loading approaches 80 g Pu/L resin.

Kyser, E.; King, W.; O'Rourke, P.

2012-07-26

256

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

257

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

258

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

259

SULFIDE METHOD PLUTONIUM SEPARATION  

DOEpatents

A process is described for the recovery of plutonium from neutron irradiated uranium solutions. Such a solution is first treated with a soluble sullide, causing precipitation of the plutoniunn and uraniunn values present, along with those impurities which form insoluble sulfides. The precipitate is then treated with a solution of carbonate ions, which will dissolve the uranium and plutonium present while the fission product sulfides remain unaffected. After separation from the residue, this solution may then be treated by any of the usual methods, such as formation of a lanthanum fluoride precipitate, to effect separation of plutoniunn from uranium.

Duffield, R.B.

1958-08-12

260

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

261

Extraction of Uranium, Neptunium and Plutonium from Caustic Media  

SciTech Connect

5 Fundamental research on uranium, neptunium and plutonium separation from alkaline media using solvent extraction is being conducted. Specific extractants for these actinides from alkaline media have been synthesized to investigate the feasibility of selective removal of these elements. Two families of extractants have been studied: terephthalamide and tetra(hydroxybenzyl)ethylene diamine derivatives. Fundamental studies were conducted to characterize their extraction behavior from a wide variety of aqueous conditions. The terephthalamide derivatives exhibit a significant extraction strength along with a discriminatory behavior among the actinides, plutonium being extracted the most strongly. Quantitative extraction of plutonium and moderate extraction of neptunium and uranium was achieved from a simple caustic solution. Interestingly, strontium is also quantitatively extracted by these derivatives. However, their stability to highly caustic solutions still needs to be imp roved. Tetra(hydroxybenzyl)ethylene diamine derivatives exhibit a very good stability to caustic conditions and are currently being studied.

Delmau, Laetitia H.; Bonnesen, Peter V.; Engle, Nancy L.; Raymond, Kenneth N.; Xu, Jade

2004-03-28

262

Recovery of plutonium from electrorefining anode heels at Savannah River  

SciTech Connect

In a joint effort, the Savannah River Laboratory (SRL), Savannah River Plant (SRP), and the Rocky Flats Plant (RFP) have developed two processes to recover plutonium from electrorefining anode heel residues. Aqueous dissolution of anode heel metal was demonstrated at SRL on a laboratory scale and on a larger pilot scale using either sulfamic acid or nitric acid-hydrazine-fluoride solutions. This direct anode heel metal dissolution requires the use of a geometrically favorable dissolver. The second process developed involves first diluting the plutonium in the anode heel residues by alloying with aluminum. The alloyed anode heel plutonium can then be dissolved using a nitric acid-fluoride-mercury(II) solution in large non-geometrically favorable equipment where nuclear safety is ensured by concentration control.

Gray, J.H.; Gray, L.W.; Karraker, D.G.

1987-03-01

263

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

264

METHOD OF MAINTAINING PLUTONIUM IN A HIGHER STATE OF OXIDATION DURING PROCESSING  

DOEpatents

This patent deals with the oxidation of tetravalent plutonium contained in an aqueous acid solution together with fission products to the hexavalent state, prior to selective fission product precipitation, by adding to the solution bismuthate or ceric ions as the oxidant and a water-soluble dichromate as a holding oxidant. Both oxidant and holding oxidant are preferably added in greater than stoichiometric quantities with regard to the plutonium present.

Thompson, S.G.; Miller, D.R.

1959-06-30

265

Collector for recovering gallium from weapons plutonium  

SciTech Connect

Currently, the separation of gallium from weapons plutonium involves the use of aqueous processing using either solvent extraction of ion exchange. However, this process generates significant quantities of liquid radioactive wastes. A Thermally Induced Gallium Removal process, or TIGR, developed by researchers at Los Alamos National Laboratories, is a simpler alternative to aqueous processing. This research examined this process, and the behavior of gallium suboxide, a vapor that is swept away by passing hydrogen/argon over gallium trioxide/plutonium oxide heated at 1100 C during the TIGR process. Through experimental procedures, efforts were made to prevent the deposition of corrosive gallium onto furnace and vent surfaces. Experimental procedures included three options for gallium removal and collection: (1) collection of gallium suboxide through use of a cold finger; (2) collection by in situ air oxidation; and (3) collection of gallium on copper. Results conclude all three collection mechanisms are feasible. In addition, gallium trioxide exists in three crystalline forms, and each form was encountered during each experiment, and that each form will have a different reactivity.

Philip, C.V.; Anthony, R.G.; Chokkaram, S. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemical Engineering

1998-09-01

266

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

267

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

268

The politics of plutonium  

Microsoft Academic Search

The first major setback to the development of FBR's occurred in 1971 whe the Scientists' Institute for Public Information brought suit against AEC for its failure to write an environmental impact statement on the FBR development program. The legal and administrative developments that have brought anti-plutonium attitudes from a minority position to widely accepted policy are outlined. Such nuclear accidents

J. Abbotts; H. Wasserman

1978-01-01

269

Plutonium: Requiem or reprieve  

Microsoft Academic Search

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

Pillay; K. K. S

1996-01-01

270

Plutonium Disposition by Immobilization  

SciTech Connect

The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be encapsulated within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2008 and be completed within 10 years. In support of this goal, the DOE Office of Fissile Materials Disposition (MD) is conducting development and testing (D&T) activities at four DOE laboratories under the technical leadership of Lawrence Livermore National Laboratory (LLNL). The Savannah River Site has been selected as the site for the planned Plutonium Immobilization Plant (PIP). The D&T effort, now in its third year, will establish the technical bases for the design, construction, and operation of the U. S. capability to immobilize surplus plutonium in a suitable and cost-effective manner. Based on the D&T effort and on the development of a conceptual design of the PIP, automation is expected to play a key role in the design and operation of the Immobilization Plant. Automation and remote handling are needed to achieve required dose reduction and to enhance operational efficiency.

Gould, T.; DiSabatino, A.; Mitchell, M.

2000-03-07

271

Plutonium metal turnings fire  

Microsoft Academic Search

On July 27, 1954, 965 grams of plutonium alloy contained in three standard quart size ice cream cartons were being removed from the process line by two process operators using the plastic bag technique. Shortly after the plastic bag scaler had been energized a brown spot appeared on the plastic bag. The glowing turnings burned through the containers and plastic

Pierick

1954-01-01

272

Plutonium: Facts and Inferences.  

National Technical Information Service (NTIS)

This report reviews the knowledge that we have about plutonium from the point of view of the inferences that can be drawn from such knowledge relative to the implications for society of the creation of this element in a nuclear power industry. It represen...

C. L. Comar W. B. Seefeldt W. J. Mecham M. J. Steindler B. L. Cohen

1976-01-01

273

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

274

Accurate quantification of radioactive materials by x-ray fluorescence : gallium in plutonium metal /.  

SciTech Connect

Two XRF specimen preparation methods were investigated for quantifying gallium in plutonium metal. Gallium in plutonium was chosen here as an example for demonstrating the efficacy of wavelength dispersive XRF for quantifying radioactive materials. The steps necessary to handle such materials safely will also be discussed. Quantification of plutonium samples by a well-established aqueous specimen preparation method resulted in relative precision and accuracy values of well less than 1%. As an alternative to the aqueous approach, a dried residue method was studied. Quantification of gallium in samples using this method resulted in relative precision and accuracy values an order of magnitude worse, but the method is faster, safer, and generates less waste than the aqueous process. The specimen preparation details and analysis results using each method will be presented here.

Worley, C. G. (Christopher G.)

2002-01-01

275

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

276

Complexation of Plutonium (IV) with Sulfate at Variable Temperatures  

SciTech Connect

The complexation of plutonium(IV) with sulfate at variable temperatures from 25o C to 55o C has been investigated by solvent extraction method. A NaBrO3 as holding oxidant was used to maintain plutonium in the Pu(IV) oxidation state throughout the experiments. The distribution ratio of Pu(IV) between the organic and aqueous phases was found to decrease as the concentrations of sulfate were increased. Stability constants of the 1:1 and 1:2 Pu(IV)-HSO4- complexes, dominant in the aqueous phase under the experimental conditions, were calculated from the effect of [HSO4-] on the distribution ratio. The enthalpy and entropy of complexation were calculated from the stability constants at different temperatures by using the Van’t Hoff equation.

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

2007-10-01

277

Recovery of americium-241 from aged plutonium metal  

SciTech Connect

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

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

1980-12-01

278

Cloud processing of nitrate  

NASA Astrophysics Data System (ADS)

The role of clouds in the transport and transformation of tropospheric pollutants was investigated through airborne measurements made out of Cleveland, Ohio, from 21 July to 18 August 2004, as part of the International Consortium for Atmospheric Research on Transport and Transformation 2004 program. Observations of gas-phase nitrate, size-resolved particulate nitrate, cloud water nitrate, and size-distributed cloud residual nitrate are used to examine changes in the partitioning of nitrate from precloud to postcloud as a function of particle size. The [NO3-]/[SO42-] ratio was highest in the bulk cloud water and higher in the cloud droplet residuals compared with the below-cloud aerosols. Most of the nitrate entered the cloud water as HNO3, and in 30% of 43 size distributions examined, the nitrate in the cloud droplets was found in residual particle sizes smaller than those of sulfate. Simulations from a trace gas-aerosol-cloud parcel model show that this size difference results from differences in the processes by which nitrate and sulfate enter cloud water. The transfer of HNO3 to cloud droplets is governed primarily by gas-phase mass transfer to the droplets, leading to greater accumulation in the smaller, more numerous droplets with higher total surface area. In contrast, much of the sulfate in the cloud water is the result of nucleation scavenging, which distributes the sulfate mass toward slightly larger sizes. The extent of separation between nitrate and sulfate is dependent on the cloud base sulfate size distribution and the factors that govern both HNO3 and SO2 uptake, with subsequent S(IV) oxidation.

Hayden, K. L.; MacDonald, A. M.; Gong, W.; Toom-Sauntry, D.; Anlauf, K. G.; Leithead, A.; Li, S.-M.; Leaitch, W. R.; Noone, K.

2008-09-01

279

Halide Ion Enhancement of Nitrate Ion Photolysis  

NASA Astrophysics Data System (ADS)

Nitrate ion photochemistry is an important source of NOx in the polar regions. It is uncertain whether coexisting ions such as halides play a role in nitrate photochemistry. The effect of halides on NO3 photolysis was investigated using photolysis experiments in 230 L Teflon chambers that contain deliquesced aerosols of NaBr:NaNO3, KBr:KNO3 and ternary mixtures of NaCl:NaBr:NaNO3. Gas phase NO2 and gaseous halogen products were measured as a function of photolysis time using long path FTIR, NOx chemiluminescence and API-MS (atmospheric pressure ionization mass spectrometry). Experiments were conducted with NO3- held at a constant 0.5 M and with the amount of total halide concentration varying from 0.25 M to 4 M. Studies on NaBr:NaNO3 mixtures suggest that as the bromide ion to nitrate ion ratio increases, there is an enhancement in the rate of production of NO2 in the nitrate-bromide mixtures over that formed in the photolysis of NaNO3. Molecular dynamic (MD) simulations provide molecular level insight into the ions near the air-water interface in the aqueous halide-nitrate mixtures. These studies suggest that the presence of sodium halides at the air-water interface may encourage some nitrate ions to approach the top layers of water, allowing for more efficient escape of photoproducts than is seen in the absence of halides. Experiments on mixtures of KBr:KNO3 are being conducted to determine potential cation effects. In addition, ternary mixtures of NaCl:NaBr:NaNO3 are being examined to determine the effects of mixtures of halides on production of NO2 and gaseous halogen products. The implications of this photochemistry for tropospheric chemistry will be discussed.

Richards, N. K.; Wingen, L. M.; Callahan, K. M.; Tobias, D. J.; Finlayson-Pitts, B. J.

2009-12-01

280

Electrolytic removal of nitrate from crop residues.  

PubMed

The Controlled Ecological Life Support System (CELSS) resource recovery system, which is a waste-processing system,uses aerobic and anaerobic bioreactors to recover plants nutrients and secondary foods from the inedible biomass. Crop residues contain a significant amount of nitrate. There are actually two major problems concerning nitrate: 1) both CELSS biomass production and resource recovery consume large quantities of nitric acid, and 2) nitrate causes a variety of problems in both aerobic and anaerobic bioreactors. The nitrate anion causes several problems in the resource recovery system in such a way that removal prior to the process is highly desirable. The technique proposed to remove nitrate from potato inedible biomass leachate and to satisfy the nitric acid demand was a four-compartment electrolytic cell. In order to establish the electrolytic cell performance variables, experiments were carried out using potato crop residue aqueous leachate as the diluate solution. The variables studied were the potato biomass leachate composition and electrical properties, preparation of compartment solutions to be compatible with the electrolytic system, limiting current density, nutrients removal rates as a function of current density, fluid hydrodynamic conditions, applied voltage, and process operating time during batch recirculation operation. Results indicated that the limiting current density (maximum operating current density) was directly proportional to the solution electrical conductivity an a power function of the linear fluid velocity in the range between 0.083 and 0.403 m/s. During the electrolytic cell once-through operation, the nitrate, potassium, and other nutrient removal rates were proportional to the current density and were inversely proportional to fluid velocity. The removal of monovalent ions was found to be higher than divalent ones. Under batch recirculation operation at constant applied voltage of 4.5 and 8.5 V, it was found that the nutrient removal rates were independent of applied voltage, but were proportional to the ions concentration and operating time. PMID:11676458

Colon, G; Sager, J C

2001-01-01

281

INFRARED SPECTRA OF URANYL NITRATE HYDRATES AND RUBIDIUM URANYL NITRATE  

Microsoft Academic Search

The infrared spectra of uranyl nitrate di-, tri-, and hexahydrate have ; been examined from 3700 to 700 cm⁻¹, with nitrogen of normal isotopic ; composition and enriched in N¹⁵, and most of the bands are assigned. The ; spectrum of uranyl nitrate hexahydrate is in most respects that of a typical ; ionic nitrate. The spectra of uranyl nitrate

Bryan M. Gatehouse; Alan E. Comyns

1958-01-01

282

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

283

The Chilean nitrate deposits.  

USGS Publications Warehouse

The nitrate deposits in the arid Atacama desert of northern Chile consist of saline-cemented surficial material, apparently formed in and near a playa lake that formerly covered the area. Many features of their distribution and chemical composition are unique. The author believes the principal sources of the saline constituents were the volcanic rocks of late Tertiary and Quaternary age in the Andes and that the nitrate is of organic origin. Possible sources of the nitrate, iodate, perchlorate and chromate are discussed. -J.J.Robertson

Ericksen, G. E.

1983-01-01

284

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

285

The effect of fluoride and aluminum on the anion exchange of plutonium from nitric acid  

SciTech Connect

Anion exchange in nitric acid is a prominent aqueous process used to recover and purify plutonium from impure nuclear materials. This process is sensitive to fluoride ion, which complexes plutonium in competition with the anionic nitrato complex that is strongly sorbed on the anion exchange column. Fluoride interference traditionally has been counteracted by adding a masking agent, such as aluminum, that forms competing complexes with fluoride. The interfering effect of fluoride is known to be a function not only of the fluoride-to-aluminum ratio but also of the fluoride-to-plutonium ratio. This report summarizes a Los Alamos study of the effect of 25 fluoride-aluminum-plutonium conmbinations on the anion exchange sorption of plutonium. Five aluminum-to-plutonium ratios ranging from 0.10 to 10 were each evaluated at five fluoride-to-aluminum ratios that ranged from 0 to 6. The fluoride-to-plutonium ratio has a greater influence on plutonium sorption than does the fluoride-to-aluminum ratio. Aluminum was less effective as a masking agent than had been assumed, because measurable fluoride interference occurred at all levels of added aluminum.

Marsh, S.F.

1987-07-01

286

Lithium metal reduction of plutonium oxide to produce plutonium metal  

SciTech Connect

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 recaptured product lithium oxides with anhydrous hydrochloric acid to produce lithium chloride salt; and decomposing product lithium chloride salt by electrolysis to regenerate lithium metal.

Coops, M.S.

1992-06-02

287

Stereoregular Polyvinyl Nitrate.  

National Technical Information Service (NTIS)

Isotactic polyvinyl nitrate (PVN) was prepared to investigate the effect of stereorgularity on the physical properties of PVN. The isotatic PVN had a higher softening point and was more difficult to stabilize than regular PVN. (Author)

R. A. Strecker

1980-01-01

288

Oxidation of plutonium dioxide.  

PubMed

The physics and chemistry of the actinide elements form the scientific basis for rational handling of nuclear materials. In recent experiments, most unexpectedly, plutonium dioxide has been found to react with water to form higher oxides up to PuO(2.27), whereas PuO(2) had always been thought to be the highest stable oxide of plutonium. We perform a theoretical analysis of this complicated situation on the basis of total energies calculated within density functional theory combined with well-established thermodynamic data. The reactions of PuO(2) with either O(2) or H(2)O to form PuO(2+delta) are calculated to be endothermic: that is, in order to occur they require a supply of energy. However, our calculations show that PuO(2+delta) can be formed, as an intermediate product, by reactions with the products of radiolysis of water, such as H(2)O(2). PMID:15034561

Korzhavyi, Pavel A; Vitos, Levente; Andersson, David A; Johansson, Börje

2004-03-14

289

Plutonium recovery from organic materials  

DOEpatents

A method is described for removing plutonium or the like from organic material wherein the organic material is leached with a solution containing a strong reducing agent such as titanium (III) (Ti/sup +3None)/, chromium (II) (Cr/ sup +2/), vanadium (II) (V/sup +2/) ions, or ferrous ethylenediaminetetraacetate (EDTA), the leaching yielding a plutonium-containing solution that is further processed to recover plutonium. The leach solution may also contain citrate or tartrate ion. (Official Gazette)

Deaton, R.L.; Silver, G.L.

1973-12-11

290

PROCESS OF PRODUCING SHAPED PLUTONIUM  

DOEpatents

A process is presented for producing and casting high purity plutonium metal in one step from plutonium tetrafluoride. The process comprises heating a mixture of the plutonium tetrafluoride with calcium while the mixture is in contact with and defined as to shape by a material obtained by firing a mixture consisting of calcium oxide and from 2 to 10% by its weight of calcium fluoride at from 1260 to 1370 deg C.

Anicetti, R.J.

1959-08-11

291

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

292

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

293

CESIUM RECOVERY FROM AQUEOUS SOLUTIONS  

DOEpatents

A process for recovering cesium from aqueous solutions is given in which precipitation on zinc ferricyanide is used. The precipitation is preferably carried out in solutions containing at least 0.0004M zinc ferricyanide, an acidity ranging from 0.2N mineral acid to 0.61N acid deficiency, and 1 to 2.5M aluminum nitrate. (D.L.C.)

Goodhall, C.A.

1960-09-13

294

Protein tyrosine nitration  

PubMed Central

Nitric oxide metabolism in plant cells has a relative short history. Nitration is a chemical process which consists of introducing a nitro group (-NO2) into a chemical compound. in biological systems, this process has been found in different molecules such as proteins, lipids and nucleic acids that can affect its function. This mini-review offers an overview of this process with special emphasis on protein tyrosine nitration in plants and its involvement in the process of nitrosative stress.

Chaki, Mounira; Leterrier, Marina; Barroso, Juan B

2009-01-01

295

MOLDS FOR CASTING PLUTONIUM  

DOEpatents

A coated mold for casting plutonium comprises a mold base portion of a material which remains solid and stable at temperatures as high as the pouring temperature of the metal to be cast and having a thin coating of the order of 0.005 inch thick on the interior thereof. The coating is composed of finely divided calcium fluoride having a particle size of about 149 microns. (AEC)

Anderson, J.W.; Miley, F.; Pritchard, W.C.

1962-02-27

296

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

297

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

SciTech Connect

Approximately 15,000 L of solution containing isotopes of americium and curium (Am/Cm) will undergo stabilization by vitrification at the Savannah River Site (SRS). Prior to vitrification, an in-tank pretreatment will be used to remove metal impurities from the solution using an oxalate precipitation process. Material balance calculations for this process, based on solubility data in pure nitric acid, predict approximately 80 percent of the plutonium in the solution will be lost to waste. Due to the uncertainty associated with the plutonium losses during processing, solubility experiments were performed to measure the recovery of plutonium during pretreatment and a subsequent precipitation process to prepare a slurry feed for a batch melter. A good estimate of the plutonium content of the glass is required for planning the shipment of the vitrified Am/Cm product to Oak Ridge National Laboratory (ORNL).The plutonium solubility in the oxalate precipitation supernate during pretreatment was 10 mg/mL at 35 degrees C. In two subsequent washes with a 0.25M oxalic acid/0.5M nitric acid solution, the solubility dropped to less than 5 mg/mL. During the precipitation and washing steps, lanthanide fission products in the solution were mostly insoluble. Uranium, and alkali, alkaline earth, and transition metal impurities were soluble as expected. An elemental material balance for plutonium showed that greater than 94 percent of the plutonium was recovered in the dissolved precipitate. The recovery of the lanthanide elements was generally 94 percent or higher except for the more soluble lanthanum. The recovery of soluble metal impurities from the precipitate slurry ranged from 15 to 22 percent. Theoretically, 16 percent of the soluble oxalates should have been present in the dissolved slurry based on the dilution effects and volumes of supernate and wash solutions removed. A trace level material balance showed greater than 97 percent recovery of americium-241 (from the beta dec ay of plutonium-241) in the dissolved precipitate, a value consistent with the recovery of europium, the americium surrogate.In a subsequent experiment, the plutonium solubility following an oxalate precipitation to simulate the preparation of a slurry feed for a batch melter was 21 mg/mL at 35 degrees C. The increase in solubility compared to the value measured during the pretreatment experiment was attributed to the increased nitrate concentration and ensuing increase in plutonium complexation. The solubility of the plutonium following a precipitant wash with 0.1M oxalic acid was unchanged. The recovery of plutonium from the precipitate slurry was greater than 97 percent allowing an estimation that approximately 92 percent of the plutonium in Tank 17.1 will report to the glass. The behavior of the lanthanides and soluble metal impurities was consistent with the behavior seen during the pretreatment experiment. A trace level material balance showed that 99.9 percent of the americium w as recovered from the precipitate slurry. The overall recovery of americium from the pretreatment and feed preparation processes was greater than 97 percent, which was consistent with the measured recovery of the europium surrogate.

Rudisill, T.S.

1999-08-11

298

Welding Plutonium Storage Containers  

SciTech Connect

The outer can welder (OCW) in the FB-Line Facility at the Savannah River Site (SRS) is a Gas Tungsten Arc Weld (GTAW) system used to create outer canisters compliant with the Department of Energy 3013 Standard, DOE-STD-3013-2000, Stabilization, Packaging, and Storage of Plutonium-Bearing Materials. The key welding parameters controlled and monitored on the outer can welder Data Acquisition System (DAS) are weld amperage, weld voltage, and weld rotational speed. Inner 3013 canisters from the Bagless Transfer System that contain plutonium metal or plutonium oxide are placed inside an outer 3013 canister. The canister is back-filled with helium and welded using the outer can welder. The completed weld is screened to determine if it is satisfactory by reviewing the OCW DAS key welding parameters, performing a helium leak check, performing a visual examination by a qualified weld inspector, and performing digital radiography of the completed weld. Canisters with unsatisfactory welds are cut open and repackaged. Canisters with satisfactory welds are deemed compliant with the 3013 standard for long-term storage.

HUDLOW, SL

2004-04-20

299

METHOD FOR OBTAINING PLUTONIUM METAL AND ALLOYS OF PLUTONIUM FROM PLUTONIUM TRICHLORIDE  

DOEpatents

A process is given for both reducing plutonium trichloride to plutonium metal using cerium as the reductant and simultaneously alloying such plutonium metal with an excess of cerium or cerium and cobalt sufficient to yield the desired nuclear reactor fuel composition. The process is conducted at a temperature from about 550 to 775 deg C, at atmospheric pressure, without the use of booster reactants, and a substantial decontamination is effected in the product alloy of any rare earths which may be associated with the source of the plutonium. (AEC)

Reavis, J.G.; Leary, J.A.; Maraman, W.J.

1962-11-13

300

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

301

Determination of nitrate ion content in recirculating water in petroleum refineries and petrochemical plants  

SciTech Connect

A method for determining nitrate ions, using a 2,6-diacetaminopyridine solution in concentrated sulfuric acid, was investigated. Potassium nitrate solutions with nitrate ion contents of 1 mg/ml, including a 2% aqueous solution of sulfamic acid, a 0.5% solution of antimony trioxide in concentrated sulfuric acid, were used. The solutions were mixed with a 1-4 ml sample of recirculating water in two 25 ml flasks. The optical density of the solution was measured relative to the zero standard of the scale of the calibration curve. Nitrate ion content was measured by the calibration curve, from data obtained in a series of 25-ml volumetric flasks.

Sukhova, N.S.; Bokova, Z.I.

1987-11-01

302

Crystallization of sodium nitrate from radioactive waste  

SciTech Connect

From the 1940s to the 1980s, the Institute of Physical Chemistry of the Russian Academy of Sciences (IPC/RAS) conducted research and development on processes to separate acetate and nitrate salts and acetic acid from radioactive wastes by crystallization. The research objective was to decrease waste volumes and produce the separated decontaminated materials for recycle. This report presents an account of the IPC/RAS experience in this field. Details on operating conditions, waste and product compositions, decontamination factors, and process equipment are described. The research and development was generally related to the management of intermediate-level radioactive wastes. The waste solutions resulted from recovery and processing of uranium, plutonium, and other products from irradiated nuclear fuel, neutralization of nuclear process solutions after extractant recovery, regeneration of process nitric acid, equipment decontamination, and other radiochemical processes. Waste components include nitric acid, metal nitrate and acetate salts, organic impurities, and surfactants. Waste management operations generally consist of two stages: volume reduction and processing of the concentrates for storage, solidification, and disposal. Filtration, coprecipitation, coagulation, evaporation, and sorption were used to reduce waste volume. 28 figs., 40 tabs.

Krapukhin, V.B.; Krasavina, E.P. Pikaev, A.K. [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Physical Chemistry

1997-07-01

303

Plutonium Immobilization Can Loading Concepts  

Microsoft Academic Search

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

E. Kriikku; C. Ward; M. Stokes; B. Randall; J. Steed; R. Jones; L. Rogers; J. Fiscus; G. Dyches

1998-01-01

304

Plutonium Immobilization Project -- Can loading  

Microsoft Academic Search

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,

Kriikku

2000-01-01

305

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

306

Preventing pollution from plutonium processing  

Microsoft Academic Search

The plutonium processing facility at Los Alamos has adopted the strategic goal of becoming a facility that processes plutonium in a way that produces only environmentally benign waste streams. Pollution prevention through source reduction and environmentally sound recycling are being pursued. General approaches to waste reductions are administrative controls, modification of process technologies, and additional waste polishing. Recycling of waste

K. K. S. Pillay

1995-01-01

307

Preventing pollution from plutonium processing  

Microsoft Academic Search

The plutonium processing facility at Los Alamos has adopted the strategic goal of becoming a facility that processes plutonium in a way that produces only environmentally benign waste streams. Pollution prevention through source reduction and environmentally sound recycling are being pursued. General approaches to waste reductions are administrative controls, modification of process technologies, and additional waste polishing. Recycling of waste

Pillay; K. K. S

1993-01-01

308

Aging phenomenon in metallic plutonium  

Microsoft Academic Search

Today, as with weapons science issues, the monitoring of plutonium aging becomes an important issue for surveillance. The reasons for this are many-fold. First, and perhaps most important, plutonium is radioactive, primarily through the process of alpha decay. This process has many consequences. One pragmatic one is that the alpha particles ejected near the surface can be used with an

M. F. Stevens; J. C. Martz

1998-01-01

309

THERMAL EXPANSION OF PLUTONIUM CARBIDES  

Microsoft Academic Search

The reaction of plutonium hydride with carbon produced a mixture of ; plutonium monocarbide and plutcnium sesquicarbide. A wrapped container enabled ; the thin-walled quartz capillary containing the specimen to be handled in a ; gloved box and to be removed without stray alpha-contamination. Welding of the ; specimen rotating msgnet in the powder camera and limitation of the temperature

Pallmer

1962-01-01

310

Criticality Calculations Using the Isopiestic Density Law of Actinide Nitrates  

SciTech Connect

Up to now, criticality safety experts used density laws fitted on experimental data and applied them outside the measurement range. Depending on the case, such an approach could be wrong for nitrate solutions. Seven components are concerned: UO{sub 2}(NO{sub 3}){sub 2}, U(NO{sub 3}){sub 4}, Pu(NO{sub 3}){sub 4}, Pu(NO{sub 3}){sub 3}, Th(NO{sub 3}){sub 4}, Am(NO{sub 3}){sub 3}, and HNO{sub 3}. To obviate this problem, a new methodology based on the thermodynamic concept of mixtures of binary electrolytes solutions (one electrolyte + water) at constant water activity, a so-called 'isopiestic' solution, has been developed by the Institute de Radioprotection et de Surete Nucleaire (IRSN) to calculate the nitrate solutions density. This paper presents its qualification by using criticality experiments. The theory and the implementation are also given.Qualification results of the uranyl and plutonium nitrate solutions show that the new density law (also called the isopiestic law) is in good agreement with the benchmarks. Thus, no bias is put into evidence for the uranium solutions, and a small negative bias equal to 0.2% is found for the plutonium solutions.Moreover, the isopiestic law corrects the observed 1% overestimation of k{sub eff} due to the empirical IRSN Leroy and Jouan density law for uranium solutions and the observed 3.4% underestimation of k{sub eff} due to the ARH-600 density law for plutonium solutions.The isopiestic density law has been implemented in CIGALES V2.0, the graphical user interface of the French criticality safety package CRISTAL that calculates the atom densities of nuclides (and writes the input file for CRISTAL computations)

Leclaire, Nicolas P. [Institut de Radioprotection et de Surete Nucleaire (France); Anno, Jacques A. [Institut de Radioprotection et de Surete Nucleaire (France); Courtois, Gerard [Institut de Radioprotection et de Surete Nucleaire (France); Dannus, Pascal [Institut National des Sciences et Techniques Nucleaires (France); Poullot, Gilles [Institut de Radioprotection et de Surete Nucleaire (France); Rouyer, Veronique [Institut de Radioprotection et de Surete Nucleaire (France)

2003-12-15

311

Search for Plutonium Fluorescence.  

National Technical Information Service (NTIS)

The possible fluorescence of aqueous Pu in its various oxidation states at room temperature was investigated, over the wavelength range of 300 to 800 nm. For each oxidation state, absorption spectral measurements were made of the experimental solutions, b...

M. A. Lyster R. L. Fellows J. P. Young

1975-01-01

312

Plutonium Multiple Recycling In PWRs  

SciTech Connect

Reprocessing and recycling open the road to a sustainable management of nuclear materials and an environment friendly management of nuclear waste. However, long or very long term recycling implies fast neutron reactors. High burn-ups of irradiated standard UO{sub 2} fuel as well as recycling of plutonium fuel in thermal reactors lead to a 'degradation' of plutonium that means a low fissile content, which is hardly compatible with recycling in LWRs. Thus the question of plutonium management has been raised; although there are some limitations, a truly large variety of options do exist; no one of the presently selected ways of plutonium management is a dead end road. Among these various options, some are fully compatible with the existing reactors and may be considered for the mid term future; they offer a competitive management of plutonium during the transition from thermal to fast reactors. (authors)

Nigon, Jean-Louis [COGEMA, DRD, 2 rue Paul Dautier 78141 Velizy - Villacoublay Cedex (France); Lenain, Richard [SERMA, CEA Saclay (France); Zaetta, Alain [SPRC - CEA Cadarache (France)

2002-07-01

313

Probing Phonons in Plutonium  

NASA Astrophysics Data System (ADS)

The phonon spectra of plutonium and its alloys have been sought after in the past few decades following the discovery of this actinide element in 1941, but with no success. This was due to a combination of the high neutron absorption cross section of 239Pu, the common isotope, and non-availability of large single crystals of any Pu-bearing materials. We have recent designed a high resolution inelastic x-ray scattering experiment using a bright synchrotron x-ray beam at the European Sychrotron Radiation Facility (ESRF), Grenoble and mapped the full phonon dispersion curves of an fcc delta-phase polycrystalline Pu-Ga alloy (1). Several unusual features including, a large elastic anisotropy, a small shear elastic modulus C', a Kohn-like anomaly in the T1[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. Our 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 d-plutonium.(2) This work was performed in collaboration with Dr. M. Krisch (ESRF)) and Prof. T.-C. Chiang (UIU), and 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. Joe Wong et al. Science, vol.301, 1078 (2003) 2. X. Dai et al. Science, vol.300, 953 (2003)

Wong, Joe

2004-03-01

314

Phototransformation of fibrate drugs in aqueous media  

Microsoft Academic Search

The photochemical conversion of bezafibrate, gemfibrozil, fenofibrate and fenofibric acid has been examined in aqueous media. Irradiation with a solar simulator in distilled water caused about 10% degradation for the first three drugs after 200 hr, while fenofibric acid was completely degraded after 100 hr. Experiments have also been performed in the presence of nitrates or humic acids, considered as environmental photosensitizers,

M. Cermola; M. DellaGreca; M. R. Iesce; L. Previtera; M. Rubino; F. Temussi; M. Brigante

2005-01-01

315

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

316

[Pharmacology of nitrates].  

PubMed

Nitrates (nitroglycerin, isosorbide dinitrate and isosorbide 5-mononitrate) are drugs used in the treatment of angina pectoris and in the prevention of myocardial ischaemia. By providing nitric oxide (NO), which, in turn, increases the level of cGMP and decreases (Ca)i, they induce effects of vasodilatation and anti-platelet aggregation. In patients suffering from endothelial dysfunction, they therefore act like exogenous NO providers. At low doses, they act as venous vasodilators by decreasing the tension (preload) and volume of the ventricle, as well as myocardial oxygen requirements (MVO2). The reduction of ventricular tension and volume also indirectly increases subendocardial blood flow. In the coronary vessels, they produce epicardial vasodilatation (all the more marked the smaller the calibre of the vessels), increase collateral blood flow and, through stenoses, induce reduction of coronary tone and the excess pressure due to vasospasm. At higher doses, the vasodilator effect is exerted on arteries and, although it reduces peripheral vascular resistance (afterload) and blood pressure, it can also produce reflex tachycardia which annihilates the reduction of MVO2. Finally, nitrates exert anti-platelet aggregation effects. All these properties account for the beneficial effects of nitrates in acute or chronic coronary ischaemic syndromes, in patients suffering from left ventricular dysfunction, during the acute phase of myocardial infarction and in post-myocardial infarction ventricular remodelling. There are many pharmaceutical formulations allowing administration of nitrates via a variety of routes. However, the efficacy of repeated nitrate administration is limited by the appearance of tolerance, which can be prevented by observing short periods without nitrates (8-24 hours). The use of sustained-release formulations, with a single daily dose, ensures a maximum anti-ischaemic effect, reduces the risk of tolerance and facilitates the patient's compliance with treatment, which makes it the treatment of choice in angina patients. PMID:9452771

Tamargo Menendez, J; Delpón, E

317

PROBABLE VOLATILIZATION OF PLUTONIUM DURING A FIRE  

Microsoft Academic Search

Fire hazards involving plutonium are discussed. The available ; experimental information was evaluated and compared with theoretical ; volatilization rates in order to make an estimate of the amount of plutonium ; released to the atmosphere in a fire. It was determined that the probable ; maximum release of plutonium is 0.08%. The most likely mechanism for releasing ; plutonium

1961-01-01

318

Cloning and Nitrate Induction of Nitrate Reductase mRNA  

Microsoft Academic Search

Nitrate is the major source of nitrogen taken from the soil by higher plants but requires reduction to ammonia prior to incorporation into amino acids. The first enzyme in the reducing pathway is a nitrate-inducible enzyme, nitrate reductase (EC 1.6.6.1). A specific polyclonal antiserum raised against purified barley nitrate reductase has been used to immunoprecipitate in vivo labeled protein and

Chi-Lien Cheng; Julia Dewdney; Andris Kleinhofs; Howard M. Goodman

1986-01-01

319

Dissolution Behavior of Plutonium Containing Zirconia-Magnesia Ceramics  

SciTech Connect

This study explores the dissolution properties of zirconia-magnesia ceramics containing plutonium as the basis of an inert atrix nuclear fuel. The magnesium oxide phase remains pure MgO, while the zirconia incorporates a small amount of magnesium oxide along with all of the plutonium oxide and erbium oxide. The performance of the material under reactor and repository environments was examined. Reactor conditions are examined using a pressure vessel to expose the material to 300 degrees C water. To assess the performance of the material as a waste form it was submerged in 90 degrees C water for 1000 h. In both aqueous dissolution studies there was minimal release of less than 0.8 wt.% of plutonium from the material. To examine the potential for recycling, the dissolution behavior of the fuel matrix was examined in acidic solutions: pure nitric acid and a nitric acid-hydrofluoric acid-peroxide solution. Both acidic media exhibit potential for dissolving plutonium from the zirconia matrix. The experiments performed in this study are meant to lay a foundation for the chemical performance of zirconia-magnesia inert matrix fuel containing fissile material and burnable poison.

Kiel Holliday; Thomas Hartmann; Gary Cerefice; Ken Czerwinski

2012-03-01

320

On NO3-H2O interactions in aqueous solutions and at interfaces  

SciTech Connect

Constrained molecular dynamics technique was employed to investigate the transport of a nitrate ion across the water liquid/vapor interface. We developed the nitrate ion-water polarizable potential capable of describing well the solvation properties of the hydrated nitrate ion. The computed free energy profile for the transfer of the nitrate ion across the air/water interface increases monotonically as the nitrate ion approaches the Gibbs dividing surface from the bulk liquid side. The computed density profiles of 1M KNO3 salt solution slab indicate that the nitrate and potassium ions are both found below the aqueous interface. Upon analyzing the results, we can conclude that the probability of finding the nitrate anion at the aqueous interface is quite small.

Dang, Liem X.; Chang, Tsun-Mei; Roeselova, Martina; Garrett, Bruce C.; Tobias, Douglas J.

2006-02-14

321

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

322

RECENT ADVANCES IN THE BASIC CHEMISTRY OF PLUTONIUM, AMERICIUM AND CURIUM  

Microsoft Academic Search

The oxidation-reduction potentials of plutonium in acid solutions were ; determined enabling the estimation of equilbrium relationships among the aqueous ; plutoniumn species from electromotive force, spectrophotomet-ric, and kinetic ; data. Advances in the chemistry of americium and curium included the discovery ; and isolation of new valence states and characterization of the metals and ; compounds. The results of

S. W. Rabideau; L. B. Asprey; T. K. Keenan; T. W. Newton

1958-01-01

323

Improved Recovery and Purification of Plutonium at Los Alamos Using Macroporous Anion Exchange Resin.  

National Technical Information Service (NTIS)

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 a...

S. F. Marsh M. J. Mann

1987-01-01

324

Synthesis and Structural Characterization of a Molecular Plutonium(IV) Compound Constructed from Dimeric Building Blocks  

SciTech Connect

Single crystals of Na8Pu2(O2)2(CO3)6•12H2O, exhibiting mu2, eta2-O2 ligands in unprecedented Pu(IV) dimeric units, were obtained at ambient temperature from aqueous Plutonium(IV) peroxide carbonate solution.

Runde, Wolfgang; Brodnax, Lia F.; Goff, George S.; Peper, Shane M.; Taw, Felicia L.; Scott, Brian L.

2007-04-01

325

Preliminary studies on the spatial-temporal microdistribution of inhaled soluble plutonium in the lungs of dogs  

SciTech Connect

The pulmonary microdistribution of inhaled soluble plutonium in four beagle dogs was studied in autoradiographs of histologic sections and transmission electron micrographs of lungs. Dogs were exposed to a single nose-only aerosol of /sup 239/Pu nitrate with a post-exposure time ranging from 1 month to 42 months. At one month after the exposure, the plutonium was dispersed throughout the lung section, with a higher percentage of the activity found on alveolar macrophages and alveolar septa. However, a nonrandom localization of the plutonium was observed as time passed. The focal concentrations were primarily in nodular or diffuse interstitial fibrotic tissues typically contiguous with subpleural, peribronchial, or perivascular areas. More than 50% of the total activity was in the form of single-tracks at one month exposure, and this percentage increased with time. In summary, this preliminary study suggests an initial random dispersion of soluble plutonium with increased concentration of activity to nonrandom focal locations with time.

Cho, M.W.; Dagle, G.E.

1987-01-01

326

Simultaneous determination of nitrite, nitrate and ascorbic acid in canned vegetable juices by reverse?phase ion?interaction HPLC  

Microsoft Academic Search

A simple ion?interaction C18 reverse?phase high performance liquid chromatographic method was developed for simultaneous determination of nitrite, nitrate and ascorbic acid in canned vegetable juices. The method makes use of 0.010 m octylammonium ortho?phosphate as the ion interacting reagent and 20% (v\\/v) aqueous methanol as the mobile phase. The content of nitrite, nitrate (expressed as nitrite ion and nitrate ion,

C. F. Cheng; C. W. Tsang

1998-01-01

327

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

328

Batch Crystallization of Uranyl Nitrate  

Microsoft Academic Search

Batch crystallization of uranyl nitrate is carried out in order to obtain fundamental data required for the development of reprocessing involving crystallization. Particular attention is paid to the development of a method for predicting the concentrations of uranium and nitric acid in the mother liquor and the amount of uranyl nitrate crystals produced. Initial concentrations of uranyl nitrate and nitric

Takahiro CHIKAZAWA; Toshiaki KIKUCHI; Atsuhiro SHIBATA; Tomozo KOYAMA; Shunji HOMMA

2008-01-01

329

Reduced-size plutonium sample processing and packaging for the PAT-2 package  

SciTech Connect

A light-water container for the air transport of plutonium safeguards samples, the PAT-2 package, has been developed in the USA and is now licensed by the US NRC (Certificate of Compliance) and the US DOT (IAEA Certificate of Competent Authority). The very limited available space in this package for plutonium-bearing samples required the design of small-size canisters to meet the needs of international safeguards. The suitability of a new small canister and vial for powder and solution samples has been tested in an intralaboratory experiment. The results of the experiment, based on the concept of pre-weighed samples, show that the tested canister and quartz vial can be used successfully for containing small size PuO/sub 2/ powder samples of homogeneous source material, as well as for dried aliguands of plutonium nitrate solutions.

Kuhn, E.; Deron, S.; Aigner, H.; Andersen, J.A.

1982-01-01

330

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

331

Microdistribution and long-term retention of 239Pu (NO3)4 in the respiratory tracts of an acutely exposed plutonium worker and experimental beagle dogs.  

PubMed

The long-term retention of inhaled soluble forms of plutonium raises concerns as to the potential health effects in persons working in nuclear energy or the nuclear weapons program. The distributions of long-term retained inhaled plutonium-nitrate [(239)Pu (NO(3))(4)] deposited in the lungs of an accidentally exposed nuclear worker (Human Case 0269) and in the lungs of experimentally exposed beagle dogs with varying initial lung depositions were determined via autoradiographs of selected histologic lung, lymph node, trachea, and nasal turbinate tissue sections. These studies showed that both the human and dogs had a nonuniform distribution of plutonium throughout the lung tissue. Fibrotic scar tissue effectively encapsulated a portion of the plutonium and prevented its clearance from the body or translocation to other tissues and diminished dose to organ parenchyma. Alpha radiation activity from deposited plutonium in Human Case 0269 was observed primarily along the subpleural regions while no alpha activity was seen in the tracheobronchial lymph nodes of this individual. However, relatively high activity levels in the tracheobronchial lymph nodes of the beagles indicated the lymphatic system was effective in clearing deposited plutonium from the lung tissues. In both the human case and beagle dogs, the appearance of retained plutonium within the respiratory tract was inconsistent with current biokinetic models of clearance for soluble forms of plutonium. Bound plutonium can have a marked effect on the dose to the lungs and subsequent radiation exposure has the potential to increase cancer risk. PMID:22962267

Nielsen, Christopher E; Wilson, Dulaney A; Brooks, Antone L; McCord, Stacey L; Dagle, Gerald E; James, Anthony C; Tolmachev, Sergei Y; Thrall, Brian D; Morgan, William F

2012-09-07

332

Nitrate reductase regulation: Effects of nitrate and light on nitrate reductase mRNA accumulation  

Microsoft Academic Search

Summary  Regulation of nitrate reductase mRNA by light and nitrate was studied in barley seedlings using a partial cDNA clone as a\\u000a probe. Nitrate reductase mRNA was detected in roots and leaves within 40 min after supplying nitrate to the roots and reached\\u000a peak accumulation at 2 h in the roots and at 12 h in the leaves. In the absence

James M. Melzer; Andris Kleinhofs; Robert L. Warner

1989-01-01

333

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

334

Efficacies of LICAM(C) and DTPA for the Decorporation of Inhaled Transportable Forms of Plutonium and Americium from the Rat  

Microsoft Academic Search

Fhe efficacies of N 1, N5, N10, N14-tetrakis (2,3-dihydroxy-4-carboxybenzoyl)-tetra-azatetradecane LICAM(C)] and diethylenetriaminepenta-acetic acid (DTPA) (30 ?mol\\/kg body wt.) have been nvestigated for plutonium (Pu) decorporation after inhalation as the nitrate or tributyl phosphate TBP) complexes and the data compared with those obtained after its intravenous injection as the :itrate. The efficacy of removal of americium (Am) inhaled as the nitrate

G. N. Stradling; J. W. Stather; S. A. Gray; J. C. Moody; M. Ellender; A. Hodgson

1986-01-01

335

Plutonium waste incineration using pyrohydrolysis.  

National Technical Information Service (NTIS)

Waste generated by Savannah River Site (SRS) plutonium operations includes a contaminated organic waste stream. A conventional method for disposing of the organic waste stream and recovering the nuclear material is by incineration. When the organic materi...

M. L. Meyer

1991-01-01

336

METHOD OF DISSOLVING MASSIVE PLUTONIUM  

DOEpatents

Massive plutonium can be dissolved in a hot mixture of concentrated nitric acid and a small quantity of hydrofluoric acid. A preliminary oxidation with water under superatmospheric pressure at 140 to 150 deg C is advantageous

Facer, J.F.; Lyon, W.L.

1960-06-28

337

Plutonium Diffusivity in Compacted Bentonite.  

National Technical Information Service (NTIS)

Measurement on plutonium diffusivity in water-saturated compacted bentonite was carried out. Representative specimens of sodium bentonite were taken from Tsukinuno and Kuroishi mines situated in northeast Japan. Tsukinuno bentonite was divided into three ...

K. Idemitsu K. Ishiguro Y. Yusa N. Sasaki N. Tsunoda

1989-01-01

338

TERNARY ALLOY-CONTAINING PLUTONIUM  

DOEpatents

Ternary alloys of uranium and plutonium containing as the third element either molybdenum or zirconium are reported. Such alloys are particularly useful as reactor fuels in fast breeder reactors. The alloy contains from 2 to 25 at.% of molybdenum or zirconium, the balance being a combination of uranium and plutonium in the ratio of from 1 to 9 atoms of uranlum for each atom of plutonium. These alloys are prepared by melting the constituent elements, treating them at an elevated temperature for homogenization, and cooling them to room temperature, the rate of cooling varying with the oomposition and the desired phase structure. The preferred embodiment contains 12 to 25 at.% of molybdenum and is treated by quenching to obtain a body centered cubic crystal structure. The most important advantage of these alloys over prior binary alloys of both plutonium and uranium is the lack of cracking during casting and their ready machinability.

Waber, J.T.

1960-02-23

339

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

340

Actinide recovery using aqueous biphasic extraction: Initial developmental studies  

SciTech Connect

Aqueous biphasic extraction systems are being developed to treat radioactive wastes. The separation technique involves the selective partitioning of either solutes or colloid-size particles between two scible aqueous phases. Wet grinding of plutonium residues to an average particle size of one micron will be used to liberate the plutonium from the bulk of the particle matrix. The goal is to produce a plutonium concentrate that will integrate with existing and developing chemical recovery processes. Ideally, the process would produce a nonTRU waste stream. Coupling physical beneficiation with chemical processing will result in a substantial reduction in the volume of mixed wastes generated from dissolution recovery processes. As part of this program, we will also explore applications of aqueous biphasic extraction that include the separation and recovery of dissolved species such as metal ions and water-soluble organics. The expertise and data generated in this work will form the basis for developing more cost-effective processes for handling waste streams from environmental restoration and waste management activities within the DOE community. This report summarizes the experimental results obtained during the first year of this effort. Experimental efforts were focused on elucidating the surface and solution chemistry variables which govern partitioning behavior of plutonium and silica in aqueous biphasic extraction systems. Additional efforts were directed toward the development of wet grinding methods for producing ultrafine particles with diameters of one micron or less.

Chaiko, D.J.; Mensah-Biney, R.; Mertz, C.J.; Rollins, A.N.

1992-08-01

341

Sulfate, nitrate declines noted  

NASA Astrophysics Data System (ADS)

An analysis of more than 4000 samples of precipitation that were collected weekly from 1978 through 1983 at 19 sites in 13 states showed no clear pattern of changes in overall acidity, according to a recent report by the U.S. Geological Survey (USGS) of the Department of the Interior. The analysis did, however, reveal significant declines in sulfate and nitrate concentrations during that 5-year period.USGS hydrologists said that sulfate and nitrate, sometimes used as indirect indicators of the acidity of precipitation, showed widespread and substantial downward trends in the eastern United States. (All but three of the 19 stations are located east of the Mississippi River.) At the five stations in Ohio, Pennsylvania, and West Virginia, for example, sulfate concentrations declined 25% to 40% during the 5-year period. Only two of those five stations showed statistically significant trends in pH; these were decreases in acidity comparable to the decreases in sulfate.

342

Adsorption of plutonium oxide nanoparticles.  

PubMed

Adsorption of monodisperse cubic plutonium oxide nanoparticles ("Pu-NP", [Pu(38)O(56)Cl(x)(H(2)O)(y)]((40-x)+), with a fluorite-related lattice, approximately 1 nm in edge size) to the muscovite (001) basal plane from aqueous solutions was observed in situ (in 100 mM NaCl background electrolyte at pH 2.6). Uptake capacity of the surface quantified by ?-spectrometry was 0.92 ?g Pu/cm(2), corresponding to 10.8 Pu per unit cell area (A(UC)). This amount is significantly larger than that of Pu(4+) needed for satisfying the negative surface charge (0.25 Pu(4+) for 1 e(-)/A(UC)). The adsorbed Pu-NPs cover 17% of the surface area, determined by X-ray reflectivity (XR). This correlates to one Pu-NP for every 14 unit cells of muscovite, suggesting that each particle compensates the charge of the unit cells onto which it adsorbs as well as those in its direct proximity. Structural investigation by resonant anomalous X-ray reflectivity distinguished two different sorption states of Pu-NPs on the surface at two different regimes of distance from the surface. A fraction of Pu is distributed within 11 Å from the surface. The distribution width matches the Pu-NP size, indicating that this species represents Pu-NPs adsorbed directly on the surface. Beyond the first layer, an additional fraction of sorbed Pu was observed to extend more broadly up to more than 100 Å from the surface. This distribution is interpreted as resulting from "stacking" or aggregation of the nanoparticles driven by sorption and accumulation of Pu-NPs at the interface although these Pu-NPs do not aggregate in the solution. These results are the first in situ observation of the interaction of nanoparticles with a charged mineral-water interface yielding information important to understanding the environmental transport of Pu and other nanophase inorganic species. PMID:22216888

Schmidt, Moritz; Wilson, Richard E; Lee, Sang Soo; Soderholm, L; Fenter, P

2012-01-25

343

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

344

Structure and spectroscopy of hydrated neptunyl(vi) nitrate complexes.  

PubMed

Complexation between hexavalent neptunium and nitrate was studied in aqueous nitric acid solution using optical absorption, vibrational and X-ray absorption spectroscopies. Distributions of aqueous [NpO2](2+), [NpO2(NO3)](+) and [NpO2(NO3)2] species were obtained as a function of nitric acid concentration between 0 and 14 M. The crystal structure of [NpO2(NO3)2(H2O)2]·H2O was determined. PMID:24042456

Lindqvist-Reis, Patric; Apostolidis, Christos; Walter, Olaf; Marsac, Remi; Banik, Nidhu Lal; Skripkin, Mikhail Yu; Rothe, Jörg; Morgenstern, Alfred

2013-10-15

345

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

346

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

347

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...

348

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...

349

Roentgenoluminescence of hexahydrate of uranyl nitrate in phosphoric acid solution  

NASA Astrophysics Data System (ADS)

The fluorescence (FL) and roentgenoluminescence (XRL) spectra of yellow aqueous solution of hexahydrate of uranyl nitrate phosphoric acid solution have been measured. The XRL spectrum was compared with the XRL of the green alkali alumino-phosphate glasses doped with uranium. It was shown that both the FL and XRL were due to uranyl groups. The radiative transitions are ascribed to3?1u ?1?{g/+}.

Ožvoldová, M.

1992-08-01

350

Roentgenoluminescence of hexahydrate of uranyl nitrate in phosphoric acid solution  

Microsoft Academic Search

The fluorescence (FL) and roentgenoluminescence (XRL) spectra of yellow aqueous solution of hexahydrate of uranyl nitrate phosphoric acid solution have been measured. The XRL spectrum was compared with the XRL of the green alkali alumino-phosphate glasses doped with uranium. It was shown that both the FL and XRL were due to uranyl groups. The radiative transitions are ascribed to3?1u ?1?g+.

M. Ozvoldová

1992-01-01

351

Bismuth nitrate pentahydrate-induced novel nitration of eugenol  

PubMed Central

Background Eugenol, the main constituent of clove oil possesses a number of medicinal activities. To enhance the medicinal property, structural modification is required. On the other hand, bismuth nitrate pentahydrate has been established as an excellent eco-friendly nitrating agent for several classes of organic compounds. Results Bismuth nitrate pentahydrate-induced nitration of eugenol has been investigated very thoroughly. Twenty five different conditions have been studied. The microwave-induced solvent-free reaction has been identified as the best condition. Conclusions Spectral analyses confirm that 5-nitroeugenol is the sole product in all the cases. No oxidized or isomerized product could be detected.

2011-01-01

352

49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.  

Code of Federal Regulations, 2010 CFR

...nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

2010-10-01

353

49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.  

Code of Federal Regulations, 2010 CFR

...nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

2009-10-01

354

Nitrate Reductase from Monoraphidium braunii  

PubMed Central

Homogeneous nitrate reductase (EC 1.6.6.2) from Monoraphidium braunii was obtained by means of affinity chromatography in blue-Sepharose and gel filtration. After electrophoresis in polyacrylamide, gel slices containing pure nitrate reductase were disrupted and injected into previously unimmunized rabbits. The antiserum produced after several weeks was found to inhibit the different activities of nitrate reductase to a similar degree. Monospecificity of the antiserum was demonstrated by Ouchterlony double diffusion and crossed immunoelectrophoresis. The antibodies were purified by immunoabsorption to Sepharose-bound nitrate reductase. The intracellular location of nitrate reductase in green algae was examined by applying an immunocytochemical method to M. braunii cells. Ultrathin frozen sections were first treated with immunopurified anti-nitrate reductase monospecific antibodies, followed by incubation with colloidal gold-labeled goat antirabbit immunoglobulin G as a marker. The enzyme was specifically located in the pyrenoid region of the chloroplast. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5

Lopez-Ruiz, Antonio; Roldan, Jose Manuel; Verbelen, Jean Pierre; Diez, Jesus

1985-01-01

355

Double shell tanks plutonium inventory assessment  

SciTech Connect

This report provides an evaluation that establishes plutonium inventory estimates for all DSTs based on known tank history information, the DST plutonium inventory tracking system, tank characterization measurements, tank transfer records, and estimated average concentration values for the various types of waste. These estimates use data through December 31, 1994, and give plutonium estimates as of January 1, 1995. The plutonium inventory values for the DSTs are given in Section 31. The plutonium inventory estimate is 224 kg for the DSTs and 854 kg for the SSTs for a total of 1078 kg. This value compares favorably with the total plutonium inventory value of 981 kg obtained from the total plutonium production minus plutonium recovery analysis estimates.

Tusler, L.A.

1995-05-31

356

Determination of Particle Size Distribution of Salt Crystals in Aqueous Slurries.  

National Technical Information Service (NTIS)

A method for determining particle size distribution of water-soluble crystals in aqueous slurries is described. The salt slurries, containing sodium salts of predominantly nitrate, but also nitrite, sulfate, phosphate, aluminates, carbonate, and hydroxide...

A. G. Miller

1977-01-01

357

Plutonium focus area  

SciTech Connect

To ensure research and development programs focus on the most pressing environmental restoration and waste management problems at the U.S. Department of Energy (DOE), the Assistant Secretary for the Office of Environmental Management (EM) established a working group in August 1993 to implement a new approach to research and technology development. As part of this new approach, EM developed a management structure and principles that led to the creation of specific Focus Areas. These organizations were designed to focus the scientific and technical talent throughout DOE and the national scientific community on the major environmental restoration and waste management problems facing DOE. The Focus Area approach provides the framework for intersite cooperation and leveraging of resources on common problems. After the original establishment of five major Focus Areas within the Office of Technology Development (EM-50, now called the Office of Science and Technology), the Nuclear Materials Stabilization Task Group (EM-66) followed the structure already in place in EM-50 and chartered the Plutonium Focus Area (PFA). The following information outlines the scope and mission of the EM, EM-60, and EM-66 organizations as related to the PFA organizational structure.

NONE

1996-08-01

358

Effects of nitrate supply on plant growth, nitrate accumulation, metabolic nitrate concentration and nitrate reductase activity in three leafy vegetables  

Microsoft Academic Search

Three leafy vegetables, rape (Brassica campestris L.), Chinese cabbage (Brassica chinensis var. Oleifera Makino et Nenoto) and spinach (Spinacia oleracea L.), were grown in plastic pots with 5kg soil per pot at five nitrate supply rates, 0.00 (N1), 0.15 (N2), 0.30 (N3), 0.45 (N4), and 0.60 (N5)gNkg?1 soil to investigate the effects of nitrate supply on plant growth, nitrate accumulation

Bao-Ming Chen; Zhao-Hui Wang; Sheng-Xiu Li; Gen-Xuan Wang; Hai-Xing Song; Xi-Na Wang

2004-01-01

359

Preconceptual design for separation of plutonium and gallium by ion exchange  

SciTech Connect

The disposition of plutonium from decommissioned nuclear weapons, by incorporation into commercial UO{sub 2}-based nuclear reactor fuel, is a viable means to reduce the potential for theft of excess plutonium. This fuel, which would be a combination of plutonium oxide and uranium oxide, is referred to as a mixed oxide (MOX). Following power generation in commercial reactors with this fuel, the remaining plutonium would become mixed with highly radioactive fission products in a spent fuel assembly. The radioactivity, complex chemical composition, and large size of this spent fuel assembly, would make theft difficult with elaborate chemical processing required for plutonium recovery. In fabricating the MOX fuel, it is important to maintain current commercial fuel purity specifications. While impurities from the weapons plutonium may or may not have a detrimental affect on the fuel fabrication or fuel/cladding performance, certifying the effect as insignificant could be more costly than purification. Two primary concerns have been raised with regard to the gallium impurity: (1) gallium vaporization during fuel sintering may adversely affect the MOX fuel fabrication process, and (2) gallium vaporization during reactor operation may adversely affect the fuel cladding performance. Consequently, processes for the separation of plutonium from gallium are currently being developed and/or designed. In particular, two separation processes are being considered: (1) a developmental, potentially lower cost and lower waste, thermal vaporization process following PuO{sub 2} powder preparation, and (2) an off-the-shelf, potentially higher cost and higher waste, aqueous-based ion exchange (IX) process. While it is planned to use the thermal vaporization process should its development prove successful, IX has been recommended as a backup process. This report presents a preconceptual design with material balances for separation of plutonium from gallium by IX.

DeMuth, S.F.

1997-09-30

360

Zone refining of plutonium metal  

SciTech Connect

The purpose of this study was to investigate zone refining techniques for the purification of plutonium metal. The redistribution of 10 impurity elements from zone melting was examined. Four tantalum boats were loaded with plutonium impurity alloy, placed in a vacuum furnace, heated to 700{degrees}C, and held at temperature for one hour. Ten passes were made with each boat. Metallographic and chemical analyses performed on the plutonium rods showed that, after 10 passes, moderate movement of certain elements were achieved. Molten zone speeds of 1 or 2 inches per hour had no effect on impurity element movement. Likewise, the application of constant or variable power had no effect on impurity movement. The study implies that development of a zone refining process to purify plutonium is feasible. Development of a process will be hampered by two factors: (1) the effect on impurity element redistribution of the oxide layer formed on the exposed surface of the material is not understood, and (2) the tantalum container material is not inert in the presence of plutonium. Cold boat studies are planned, with higher temperature and vacuum levels, to determine the effect on these factors. 5 refs., 1 tab., 5 figs.

NONE

1997-05-01

361

Plutonium Proliferation: The Achilles Heel of Disarmament  

SciTech Connect

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.

Leventhal, Paul (President, Nuclear Control Institute, Washington D.C.)

2001-02-07

362

49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation...176.410 Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. (a) This...

2009-10-01

363

49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation...176.410 Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. (a) This...

2010-10-01

364

Glycine lithium nitrate crystals  

NASA Astrophysics Data System (ADS)

Crystals of glycine lithium nitrate with non-linear optical properties have been grown in a solution by slow evaporation at room temperature. The crystal shows a good thermal stability from room temperature to 175 °C where the crystal begins to degrade. This property is desirable for future technological applications. Also, a good performance on the second harmonic generation was found, characterizing the emitted dominant wavelength by a customized indirect procedure using luminance and chromaticity measured data based on the CIE-1931 standard. Additionally, the 532 nm signal was detected by using a variant to the Kurtz and Perry method.

González-Valenzuela, R.; Hernández-Paredes, J.; Medrano-Pesqueira, T.; Esparza-Ponce, H. E.; Jesús-Castillo, S.; Rodriguez-Mijangos, R.; Terpugov, V. S.; Alvarez-Ramos, M. E.; Duarte-Möller, A.

365

Reversible electric field induced nonferroelectric to ferroelectric phase transition in single crystal nanorods of potassium nitrate  

NASA Astrophysics Data System (ADS)

Single-crystal rods of the ?-phase of potassium nitrate were grown with [010] uniform crystallographic orientation inside a matrix of aluminum oxide nanopores. The pores were prepared by anodization of polished aluminum substrates. The potassium nitrate single crystals were grown inside the pores from a supersaturated aqueous solution at various temperatures. Dielectric polarization measurements of the porous film filled with the potassium nitrate crystals show an electric field induced reversible transition from the nonferroelectric ?-phase to the ferroelectric ?-phase at about 200 kV/cm. The ferroelectric ?-phase has a coercive field of about 169 kV/cm and remnant polarization of about 0.216 ?C/cm2.

Yadlovker, Doron; Berger, Shlomo

2007-10-01

366

Plutonium immobilization -- Can loading. Revision 1  

Microsoft Academic Search

The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP adds the excess plutonium to ceramic pucks, loads the pucks into cans, and places the cans into DWPF canisters. This paper discusses the PIP process steps, the can loading conceptual design, can loading equipment design, and can loading work completed.

Kriikku

2000-01-01

367

Production and destination of British civil plutonium  

Microsoft Academic Search

The amount of plutonium produced by the Magnox reactors belonging to the CEGB and SSEB is estimated using three different methods which give similar results for total plutonium production. The difference between this total and the UK civil plutonium inventory is 6.3 +\\/- 0.8 tonne. This balance was apparently sent to the United States in exchange for fissile material for

K. W. J. Barnham; D. Hart; J. Nelson; R. A. Stevens

1985-01-01

368

Decorporation approach following rat lung contamination with a moderately soluble compound of plutonium using local and systemic Ca-DTPA combined chelation.  

PubMed

Decorporation efficacy of prompt pulmonary delivery of DTPA dry powder was assessed following lung contamination with plutonium nitrate and compared to an intravenous injection of DTPA solution and a combined administration of both DTPA compounds. In addition, efficacy of a delayed treatment was assessed. In case of either early or late administration, insufflated DTPA was more efficient than intravenously injected DTPA in reducing the plutonium lung burden due to its high local concentration. Prompt treatment with DTPA powder was also more effective in limiting extrapulmonary deposits by removing the early transportable fraction of plutonium from lungs prior its absorption into blood. Translocation of DTPA from lungs to blood may also contribute to the decrease in extrapulmonary retention, as shown by reduced liver deposit after delayed pulmonary administration of DTPA. Efficacy of DTPA dry powder was further increased by the combined intravenous administration of DTPA solution for reducing extrapulmonary deposits of plutonium and promoting its urinary excretion. According to our results, the most effective treatment protocol for plutonium decorporation was the early pulmonary delivery of DTPA powder supplemented by an intravenous injection of DTPA solution. Following inhalation of plutonium as nitrate chemical form, this combined chelation therapy should provide a more effective method of treatment than conventional intravenous injection alone. At later stages following lung contamination, pulmonary administration of DTPA should also be considered as the treatment of choice for decreasing the lung burden. PMID:22799632

Grémy, Olivier; Tsapis, Nicolas; Bruel, Sylvie; Renault, Daniel; Van der Meeren, Anne

2012-07-16

369

Disposal criticality analysis for immobilized plutonium: Internal configurations  

SciTech Connect

The analysis for immobilized Pu follows the disposal criticality analysis methodology. In this study the focus is on determining the range of chemical compositions of the configurations which can occur following the aqueous degradation processes, particularly with respect to the concentrations of uranium, plutonium, and the principal neutron absorber, gadolinium. The principal analysis tool is a mass balance program that computes the amounts of plutonium, uranium, gadolinium, and chromium in solution as a function of time with inputs from a range of possible waste form dissolution rates, stainless steel corrosion rates, and compound solubilities for the neutronically significant elements. For the waste forms and degradation modes considered here, it is possible to preclude the possibility of criticality by maintaining a plutonium loading limit. Since the presence of hafnium is shown to increase this loading limit, the defense-in-depth policy would suggest the maximization of the amount of Hf as a backup criticality control material. At the end of 1997, after this study was completed, the ceramic waste form was downselected and a new formulation was developed, with the amount of Hf increased to the point where internal criticality may no longer be possible. In addition, recent calculations indicate that GdPO{sub 4} is insoluble over a much broader range of pH than is Gd{sub 2}O{sub 3}, so that its use as the Gd carrier in the waste form would provide an extra margin of defense-in-depth.

Gottlieb, P. [TRW Environmental Safety Systems, Las Vegas, NV (United States); Massari, J.R. [Framatome Cogema Fuels, Las Vegas, NV (United States); Cloke, P.L. [SAIC, Las Vegas, NV (United States)

1998-03-01

370

Spectroscopic and Electrochemical Studies of Selected Lanthanides and Actinides in Concentrated Aqueous Carbonate and Carbonate-Hydroxide Solutions and in Molten Dimethyl Sulfone.  

National Technical Information Service (NTIS)

Electrochemical and spectroscopic studies of neptunium, plutonium, americium, californium, and terbium in concentrated aqueous carbonate and carbonate-hydroxide solutions have been carried out. Changes in the absorption spectra of Np(VII), Np(V), Pu(VI), ...

P. G. Varlashkin

1985-01-01

371

The biological hazards of plutonium.  

PubMed

The health hazards associated with exposure to low levels of plutonium are reviewed since, though the world may escape a nuclear war, there may be virtually permanent contamination of the biosphere by plutonium from a number of sources. It would seem that it is possible to offer workers in the nuclear industry an acceptable level of protection but that low levels of pollution around such sites may build up until there is a hazard for people in the vicinity. The cases of childhood leukaemia found in the vicinity of the Sellafield facility may or may not be related to contamination in the area; however, plutonium is a potent carcinogen, and the foetus seems to be particularly vulnerable to it. The disposal of nuclear waste must be monitored more closely, and it is suggested that the International Atomic Energy Agency should take on this added responsibility. PMID:8047050

Freeman, S E; Ormiston-Smith, H M

372

Nitrates in myocardial infarction.  

PubMed

Until two decades ago nitroglycerin was contraindicated in acute myocardial infarction (MI). Studies in the canine model demonstrated that low-dose intravenous (i.v.) infusion, carefully titrated to decrease mean blood pressure by 10% but not below 80 mmHg, during early stages of acute MI produced marked reduction of left ventricular (LV) preload, improvement in regional perfusion, and limitation of infarct size and remodeling. However, more i.v. nitroglycerin to decrease blood pressure further resulted in a paradoxical J-curve effect, with hypoperfusion and increased infarct size. Clinical studies have confirmed that low-dose i.v. nitroglycerin infusion for the first 48 hours after acute MI is safe, not only for improving performance in LV failure, but also for limiting ischemic injury, infarct size, remodeling, and infarct-related complications, including deaths in-hospital and up to 1 year. Recent studies suggest that more prolonged therapy with nitrates spanning the healing phase of acute anterior Q-wave MI can further limit LV remodeling and preserve function. Preliminary results of the recently completed ISIS-4 megatrial suggest, however, that long-term nitrate in patients with suspected MI in the 1990s does not improve survival significantly. PMID:7848898

Jugdutt, B I

1994-08-01

373

Nitrate Reductase Activity Is Required for Nitrate Uptake into Fungal but Not Plant Cells  

Microsoft Academic Search

The ability to transport net nitrate was conferred upon transformant cells of the non-nitrate-assimilating yeast Pichia pastoris after the introduction of two genes, one encoding nitrate reductase and the other nitrate transport. It was observed that cells of this lower eukaryote transformed with the nitrate transporter gene alone failed to display net nitrate transport despite having the ability to produce

Shiela E. Unkles; Rongchen Wang; Ye Wang; Anthony D. M. Glass; Nigel M. Crawford; James R. Kinghorn

2004-01-01

374

Molecular Control of Nitrate Reductase and Other Enzymes Involved in Nitrate Assimilation  

Microsoft Academic Search

Nitrate acts as both a nutrient and a signal in plants. Nitrate induces gene expression of enzymes for its metabolism into amino acids but also has other effects on plant metabolism and development. Familiar nitrate-induced enzymes are nitrate and nitrite reductases, nitrate transporters, glutamine synthetase, glutamate synthase, ferredoxin and ferredoxin NADP+ reductase. Microarray analysis of nitrate-stimulated gene expression has identified

Wilbur H. Campbell

375

The nitrate to ammonia and ceramic (NAC) process for the denitration and immobilization of low-level radioactive liquid waste (LLW)  

Microsoft Academic Search

Hazardous radioactive liquid waste is the legacy of more than 50 years of plutonium production associated with the United States' nuclear weapons program. It is estimated that more than 245,000 tons of nitrate wastes are stored at facilities such as the single-shell tanks (SST) at the Hanford Site in the state of Washington, and the Melton Valley storage tanks at

Ivan Muguercia

1997-01-01

376

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

377

Physicochemical properties of nitrate aerosols: implications for the atmosphere.  

PubMed

As aerosols, such as sea salt and mineral dust, are transported through the atmosphere they undergo heterogeneous reactions with nitrogen oxides to form nitrate salts. The nitrate salt can have quite different physicochemical properties than the original aerosol, resulting in an aerosol that will markedly differ in its climate impact, heterogeneous chemistry, and photoactivity. In this Feature Article, we will review some aspects of the importance of aqueous nitrate aerosols as well as describe a new multi-analysis aerosol reactor system (MAARS) that is used to measure the physicochemical properties of these atmospherically relevant aerosols. Here we show measurements of the hygroscopic properties, cloud condensation nuclei activity, and FTIR extinction of nitrate salt aerosol. In particular, we have measured the hygroscopic growth of 100 nm size-selected nitrate particles including NaNO3, Ca(NO3)2, Mg(NO3)2, and a 1:1 mixture of Ca(NO3)2 and Mg(NO3)2 as a function of relative humidity (RH) at 298 K. Using Köhler theory, we have quantified the water content of these particles with increasing RH. FTIR extinction measurements of the full size distribution of each of the nitrate aerosols are analyzed to yield information about the local solvation environment of the nitrate ions and the long-wavelength light scattering of the particles at different RH. Furthermore, we have measured and compared the cloud condensation nuclei (CCN) activity of CaCO3, a large component of mineral dust aerosol, and Ca(NO3)2, a product of atmospherically aged CaCO3 through reaction with nitrogen oxides, at supersaturations from 0.1% to 0.9%. These quantitative physicochemical data are needed if we are to better understand the chemistry as well as the climate effects of atmospheric aerosols as they are entrained, transported, reacted, and aged in the atmosphere. Our studies here focus on aqueous nitrate salts, the products of the reaction of nitrogen oxides with sea salt and mineral dust aerosol. PMID:17048810

Gibson, Elizabeth R; Hudson, Paula K; Grassian, Vicki H

2006-10-26

378

Extraction of Plutonium From Spiked INEEL Soil Samples Using the Ligand-Assisted Supercritical Fluid Extraction (LA-SFE) Technique  

SciTech Connect

In order to investigate the effectiveness of ligand-assisted supercritical fluid extraction for the removal of transuranic contaminations from soils an Idaho National Engineering and Environmental Laboratory (INEEL) silty-clay soil sample was obtained from near the Radioactive Waste Management Complex area and subjected to three different chemical preparations before being spiked with plutonium. The spiked INEEL soil samples were subjected to a sequential aqueous extraction procedure to determine radionuclide portioning in each sample. Results from those extractions demonstrate that plutonium consistently partitioned into the residual fraction across all three INEEL soil preparations whereas americium partitioned 73% into the iron/manganese fraction for soil preparation A, with the balance partitioning into the residual fraction. Plutonium and americium were extracted from the INEEL soil samples using a ligand-assisted supercritical fluid extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction efficiencies ranging from 14% to 19%. After a second round wherein the initial extraction parameters were changed, the plutonium extraction efficiencies increased to 60% and as high as 80% with the americium level in the post-extracted soil samples dropping near to the detection limits. The third round of experiments are currently underway. These results demonstrate that the ligand-assisted supercritical fluid extraction technique can effectively extract plutonium from the spiked INEEL soil preparations.

Fox, R.V.; Mincher, B.J. (INEEL); Holmes, R.G.G. (British Nuclear Fuels, Inc.)

1999-08-01

379

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

380

Plutonium recovery from carbonate wash solutions  

SciTech Connect

Periodically higher than expected levels of plutonium are found in carbonate solutions used to wash second plutonium cycle solvent. The recent accumulation of plutonium in carbonate wash solutions has led to studies to determine the cause of that plutonium accumulation, to evaluate the quality of all canyon solvents, and to develop additional criteria needed to establish when solvent quality is acceptable. Solvent from three canyon solvent extraction cycles was used to evaluate technology required to measure tributyl phosphate (TBP) degradation products and was used to evaluate solvent quality criteria during the development of plutonium recovery processes. 1 fig.

Gray, J.H.; Reif, D.J.; Chostner, D.F.; Holcomb, H.P.

1991-12-31

381

Mortality of nitrate fertiliser workers  

Microsoft Academic Search

An epidemiological cohort study was conducted to investigate the mortality patterns among a group of workers engaged in the production of nitrate based fertilisers. This study was designed to test the hypothesis that individuals exposed to high concentrations of nitrates might be at increased risk of developing cancers, particularly gastric cancer. A total of 1327 male workers who had been

S Al-Dabbagh; D Forman; D Bryson; I Stratton; R Doll

1986-01-01

382

Nitration reaction modification of asphalt  

SciTech Connect

An experimental design was prepared to study the nitration reaction of asphalts at various concentrations by Fourier Transform Infrared Spectroscopy (FT-IR) and physical methods. After selection of a usable treatment level (1% by weight), the nitration reaction was performed on eight asphalts. These asphalts were evaluated by physical methods and for elastic recovery and by FT-IR.

Boucher, J.L.; Ihsiung Wang; Romine, R.A. (Southwestern Labs., Inc., Houston, TX (United States))

1990-07-01

383

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

384

TREATMENT OF AMMONIUM NITRATE SOLUTIONS  

DOEpatents

The treatment of waste solutions obtained in the processing of neutron- irradiated uranium containing fission products and ammonium nitrate is described. The object of this process is to provide a method whereby the ammonium nitrate is destroyed and removed from the solution so as to permit subsequent concentration of the solution.. In accordance with the process the residual nitrate solutions are treated with an excess of alkyl acid anhydride, such as acetic anhydride. Preferably, the residual nitrate solution is added to an excess of the acetic anhydride at such a rate that external heat is not required. The result of this operation is that the ammonium nitrate and acetic anhydride react to form N/sub 2/ O and acetic acid.

Boyer, T.W.; MacHutchin, J.G.; Yaffe, L.

1958-06-10

385

Burning weapons-grade plutonium in reactors  

SciTech Connect

As a result of massive reductions in deployed nuclear warheads, and their subsequent dismantlement, large quantities of surplus weapons- grade plutonium will be stored until its ultimate disposition is achieved in both the US and Russia. Ultimate disposition has the following minimum requirements: (1) preclude return of plutonium to the US and Russian stockpiles, (2) prevent environmental damage by precluding release of plutonium contamination, and (3) prevent proliferation by precluding plutonium diversion to sub-national groups or nonweapons states. The most efficient and effective way to dispose of surplus weapons-grade plutonium is to fabricate it into fuel and use it for generation of electrical energy in commercial nuclear power plants. Weapons-grade plutonium can be used as fuel in existing commercial nuclear power plants, such as those in the US and Russia. This recovers energy and economic value from weapons-grade plutonium, which otherwise represents a large cost liability to maintain in safeguarded and secure storage. The plutonium remaining in spent MOX fuel is reactor-grade, essentially the same as that being discharged in spent UO{sub 2} fuels. MOX fuels are well developed and are currently used in a number of LWRs in Europe. Plutonium-bearing fuels without uranium (non-fertile fuels) would require some development. However, such non-fertile fuels are attractive from a nonproliferation perspective because they avoid the insitu production of additional plutonium and enhance the annihilation of the plutonium inventory on a once-through fuel cycle.

Newman, D.F.

1993-06-01

386

PLUTONIUM SOLUBILITY IN SIMULATED SAVANNAH RIVER SITE WASTE SOLUTIONS  

SciTech Connect

To address the accelerated disposition of the supernate and salt portions of Savannah River Site (SRS) high level waste (HLW), solubility experiments were performed to develop a predictive capability for plutonium (Pu) solubility. A statistically designed experiment was used to measure the solubility of Pu in simulated solutions with salt concentrations and temperatures which bounded those observed in SRS HLW solutions. Constituents of the simulated waste solutions included: hydroxide (OH{sup -}), aluminate (Al(OH){sub 4}{sup -}), sulfate (SO{sub 4}{sup 2-}), carbonate (CO{sub 3}{sup 2-}), nitrate (NO{sub 3}{sup -}), and nitrite (NO{sub 2}{sup -}) anions. Each anion was added to the waste solution in the sodium form. The solubilities were measured at 25 and 80 C. Five sets of samples were analyzed over a six month period and a partial sample set was analyzed after nominally fifteen months of equilibration. No discernable time dependence of the measured Pu concentrations was observed except for two salt solutions equilibrated at 80 C which contained OH{sup -} concentrations >5 mol/L. In these solutions, the Pu solubility increased with time. This observation was attributed to the air oxidation of a portion of the Pu from Pu(IV) to the more soluble Pu(V) or Pu(VI) valence states. A data driven approach was subsequently used to develop a modified response surface model for Pu solubility. Solubility data from this study and historical data from the literature were used to fit the model. The model predicted the Pu solubility of the solutions from this study within the 95% confidence interval for individual predictions and the analysis of variance indicated no statistically significant lack of fit. The Savannah River National Laboratory (SRNL) model was compared with predicted values from the Aqueous Electrolyte (AQ) model developed by OLI Systems, Inc. and a solubility prediction equation developed by Delegard and Gallagher for Hanford tank waste. The agreement between measured or values predicted by the SRNL model and values predicted by the OLI AG model was very poor. The much higher predicted concentrations by the OLI AQ model appears to be the result of the model predicting the predominate Pu oxidation state is Pu(V) which is reported as unstable below sodium hydroxide (NaOH) concentrations of 6 M. There was very good agreement between the predicted Pu concentrations using the SRNL model and the model developed by Delegard and Gallagher with the exception of solutions that had very high OH{sup -} (15 M) concentrations. The lower Pu solubilities in these solutions were attributed to the presence of NO{sub 3}{sup -} and NO{sub 2}{sup -} which limit the oxidation of Pu(IV) to Pu(V).

Rudisill, T.; Hobbs, D.; Edwards, T.

2010-09-27

387

Enhanced Surface Photochemistry in Chloride-Nitrate Ion Aerosol Mixtures  

NASA Astrophysics Data System (ADS)

Heterogeneous reactions of sea salt aerosol with various oxides of nitrogen often lead to replacement of chloride ion by nitrate ion. Photolysis of aqueous nitrate at wavelengths > 290 nm leads to the production of nitrogen dioxide, hydroxyl radicals and other oxidants. The photochemistry of aerosols containing NO3- and Cl-, however, has not been investigated. Aerosols containing mixtures of NaCl and NaNO3 were used as a model system for processed sea salt aerosol. Photolysis experiments (?max = 306 nm) were performed in 55 L Teflon chambers that contained deliquesced aerosols and production of gas phase NO2 was measured as a function of time using chemiluminescence detection. Simple alkanes were added in some experiments to probe OH radical and Cl atom production. Molecular dynamics simulations were also carried out on mixed aqueous NaCl and NaNO3 slabs to help understand ion solvation in these mixed salt systems. The simulations showed that as the Cl- to NO3- ratio increases, nitrate ions are drawn toward the interface due to the large double layer of interfacial Cl- and subsurface Na+. The systems explored both experimentally and computationally included pure NaNO3 and mixtures of Cl- and NO3- in molar ratios of 1:9, 1:1, and 9:1. The photolysis experiments showed an enhanced yield of gas phase NO2 as the chloride to nitrate ratio increased. We attribute the observed enhanced NO2 yields to an increased interfacial concentration of under-coordinated nitrate ion as the ratio of Cl- to NO3- increases. The implications of these enhanced NO2 yields as sea salt aerosols become processed in the atmosphere will also be discussed.

Wingen, L. M.; Moskun, A. C.; Thomas, J. L.; Roeselova, M.; Tobias, D. J.; Finlayson-Pitts, B. J.

2007-12-01

388

Experimental Study of the Recovery of Plutonium from Non-Combustible Wastes. Final Report, April 1983-April 1985.  

National Technical Information Service (NTIS)

Removal of loose Pu0 sub 2 from non-combustible plutonium contaminated waste by Arklone (1,1,2 trichloro, 1,2,2-trifluoro ethane) has been demonstrated on a laboratory scale. While aqueous containing media are generally more effective decontaminants, Arkl...

H. E. Chamberlain J. T. Datton S. C. Gaudie J. D. Wilkins R. K. Dawson

1985-01-01

389

Mortality of nitrate fertiliser workers.  

PubMed

An epidemiological cohort study was conducted to investigate the mortality patterns among a group of workers engaged in the production of nitrate based fertilisers. This study was designed to test the hypothesis that individuals exposed to high concentrations of nitrates might be at increased risk of developing cancers, particularly gastric cancer. A total of 1327 male workers who had been employed in the production of fertilisers between 1946 and 1981 and who had been occupationally exposed to nitrates for at least one year were followed up until 1 March 1981. In total, 304 deaths were observed in this group and these were compared with expected numbers calculated from mortality rates in the northern region of England, where the factory was located. Analysis was also carried out separately for a subgroup of the cohort who had been heavily exposed to nitrates--that is, working in an environment likely to contain more than 10 mg nitrate/m3 for a year or longer. In neither the entire cohort nor the subgroup was any significant excess observed for all causes of mortality or for mortality from any of five broad categories of cause or from four specific types of cancer. A small excess of lung cancer was noted more than 20 years after first exposure in men heavily exposed for more than 10 years. That men were exposed to high concentrations of nitrate was confirmed by comparing concentrations of nitrates in the saliva of a sample of currently employed men with control men, employed at the same factory but not in fertiliser production. The men exposed to nitrate had substantially raised concentrations of nitrate in their saliva compared with both controls within the industry and with men in the general population and resident nearby. The results of this study therefore weight against the idea that exposure to nitrates in the environment leads to the formation in vivo of material amounts of carcinogens. PMID:3015194

Al-Dabbagh, S; Forman, D; Bryson, D; Stratton, I; Doll, R

1986-08-01

390

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

391

Electronic Spectra and the Mechanism of Complexing of Uranyl Nitrate in Water–Acetone Solutions  

Microsoft Academic Search

Based on the analysis of electronic absorption and luminescence spectra, the processes of complexing in an aqueous solution of uranyl nitrate hexahydrate (UO2(NO3)2·6H2O) on gradual addition of small amounts of acetone have been investigated. In a pure aqueous solution, uranyl exists as the UO2·5H2O complex. It is shown that addition of acetone to the solution leads to displacement of some

A. A. Zazhogin; A. P. Zazhogin; A. I. Komyak; A. I. Serafimovich

2003-01-01

392

Nitrates for unstable angina.  

PubMed

The term unstable angina encompasses heterogeneous clinical syndromes. Fissuring of an atherosclerotic coronary artery plaque with superimposed platelet deposition, with or without additional thrombus formation, is invariably responsible for a prolonged episode of angina at rest, increasing frequency of angina at rest, or with minimal exertion of less than 4 weeks in duration and early postinfarction angina. Plaque progression, rather than plaque fissuring, is the most likely mechanism for progressive reduction in walking distance due to angina in patients who previously have stable angina. Coronary artery spasm is responsible for Prinzmetal's variant angina, but its exact role in other forms of unstable angina is unknown. The mainstay of treatment of unstable angina (prolonged episode of angina at rest and recent onset angina at rest, or with minimal exertion with a crescendo pattern) is aspirin, heparin, or both. Both aspirin and intravenous (i.v.) heparin or their combination reduce early mortality and the incidence of acute myocardial infarction in patients hospitalized with unstable angina. However, these agents do not promptly relieve chest pain. There are no placebo-controlled studies evaluating the usefulness of nitrates in unstable angina. In open-label studies, continuous therapy with i.v. nitroglycerin (NTG) for 24 hours or longer has been shown to relieve chest pain in patients with rest angina refractory to therapy with other antianginal agents, including long-acting nitrates. Recurrence of chest pain in patients receiving i.v. NTG is a common problem and probably represents development of pharmacologic tolerance, but this can be overridden by dose escalation; protracted tolerance during short-term use of i.v. NTG is usually not a problem.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7873468

Thadani, U; Opie, L H

1994-10-01

393

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

394

Americium extraction from plutonium metal  

NASA Astrophysics Data System (ADS)

A single stage process using MgCl2 in CaCl2 has been demonstrated to remove 90% of the americium from plutonium with no transfer of impurities to the product metal except magnesium, which is readily removed in a vacuum casting operation. .

Watson, R. F.

2000-07-01

395

REVIEW OF PLUTONIUM OXIDATION LITERATURE  

Microsoft Academic Search

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

Korinko

2009-01-01

396

Japanese utilities` plutonium utilization program  

Microsoft Academic Search

Japan`s 10 utility companies are working and will continue to work towards establishing a fully closed nuclear fuel cycle. The key goals of which are: (1) reprocessing spent fuel; (2) recycling recovered uranium and plutonium; and (3) commercializing fast breeder technology by around the year 2030. This course of action by the Japanese electric power industry is in full accordance

Matsuo; Yuichiro

1996-01-01

397

Plutonium waste incineration using pyrohydrolysis  

SciTech Connect

Waste generated by Savannah River Site (SRS) plutonium operations includes a contaminated organic waste stream. A conventional method for disposing of the organic waste stream and recovering the nuclear material is by incineration. When the organic material is burned, the plutonium remains in the incinerator ash. Plutonium recovery from incinerator ash is highly dependent on the maximum temperature to which the oxide is exposed. Recovery via acid leaching is reduced for a high fired ash (>800{degree}C), while plutonium oxides fired at lower decomposition temperatures (400--800{degrees}C) are more soluble at any given acid concentration. To determine the feasibility of using a lower temperature process, tests were conducted using an electrically heated, controlled-air incinerator. Nine nonradioactive, solid, waste materials were batch-fed and processed in a top-heated cylindrical furnace. Waste material processing was completed using a 19-liter batch over a nominal 8-hour cycle. A processing cycle consisted of 1 hour for heating, 4 hours for reacting, and 3 hours for chamber cooling. The water gas shift reaction was used to hydrolyze waste materials in an atmosphere of 336% steam and 4.4% oxygen. Throughput ranged from 0.14 to 0.27 kg/hr depending on the variability in the waste material composition and density.

Meyer, M.L.

1991-01-01

398

Plutonium waste incineration using pyrohydrolysis  

SciTech Connect

Waste generated by Savannah River Site (SRS) plutonium operations includes a contaminated organic waste stream. A conventional method for disposing of the organic waste stream and recovering the nuclear material is by incineration. When the organic material is burned, the plutonium remains in the incinerator ash. Plutonium recovery from incinerator ash is highly dependent on the maximum temperature to which the oxide is exposed. Recovery via acid leaching is reduced for a high fired ash (>800{degree}C), while plutonium oxides fired at lower decomposition temperatures (400--800{degrees}C) are more soluble at any given acid concentration. To determine the feasibility of using a lower temperature process, tests were conducted using an electrically heated, controlled-air incinerator. Nine nonradioactive, solid, waste materials were batch-fed and processed in a top-heated cylindrical furnace. Waste material processing was completed using a 19-liter batch over a nominal 8-hour cycle. A processing cycle consisted of 1 hour for heating, 4 hours for reacting, and 3 hours for chamber cooling. The water gas shift reaction was used to hydrolyze waste materials in an atmosphere of 336% steam and 4.4% oxygen. Throughput ranged from 0.14 to 0.27 kg/hr depending on the variability in the waste material composition and density.

Meyer, M.L.

1991-12-31

399

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

400

Ultraviolet absorption spectrum of peroxyacetyl nitrate and peroxypropionyl nitrate. [Peroxypropionyl nitrate  

SciTech Connect

The UV absorption spectrum was measured for peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN) at 298 +/- 1 K in the 200-400-nm wavelength region. From this, the absorption cross sections for PAN and PPN have been calculated. Solar photolysis rates for PAN and PPN are estimated on the basis of the measured and extrapolated cross sections. 2 tables.

Senum, G.I.; Lee, Y.N.; Gaffney, J.S.

1984-03-29

401

Effect of nitrate ions on the efficiency of sonophotochemical phenol degradation.  

PubMed

A sonophotochemical oxidation process has been used for the treatment of an aqueous solution of phenol. The aim of this work is to evaluate the effect of nitrate ions on hydroxyl radical production and on phenol oxidation. It has been demonstrated that ultrasound can produce NOx (nitrate and nitrite), with a production rate of 2.2?Mmin(-1). The photolysis of nitrate can significantly improve the hydroxyl radical production. The apparent rate constant for hydroxyl radical production increased from 0.0015min(-1) to 0.0073min(-1) while increasing initial nitrate concentration from 0 to 0.5mM. The concentration of hydroxyl radical was directly proportional to the initial nitrate concentration. Using US/UV process, the apparent reaction rate constant of phenol degradation in the presence of nitrate reached 0.020min(-1), which was relatively lower than the value obtained (0.027min(-1)) in the absence of nitrate. It appeared that, nitrate ions can inhibit the sonochemical degradation of organic compounds such as phenol. PMID:23993458

Zaviska, François; Drogui, Patrick; El Hachemi, Errachid M; Naffrechoux, Emmanuel

2013-08-13

402

Nitrate determination using anion exchange membrane and mid-infrared spectroscopy.  

PubMed

This study investigates the combined use of an anion exchange membrane and transmittance mid-infrared spectroscopy for determining nitrate concentration in aqueous solutions and soil pastes. The method is based on immersing a small piece (2 cm(2)) of anion exchange membrane into 5 mL of solution or soil paste for 30 minutes, after which the membrane is removed, rinsed, and wiped dry. The absorbance spectrum of the charged membrane is then used to determine the amount of nitrate sorbed on the membrane. At the levels tested, the presence of carbonate or phosphate does not affect the nitrate sorption or the spectrum of the charged membrane in the vicinity of the nitrate band. Sulfate affects the spectrum of the charged membrane but does not prevent nitrate determination. For soil pastes, nitrate sorption is remarkably independent of the soil composition and is not affected by the level of soil constituents such as organic matter, clay, and calcium carbonate. Partial least squares analysis of the membrane spectra shows that there exists a strong correlation between the nitrate charge and the absorbance in the 1000-1070 cm(-1) interval, which includes the v(1) nitrate band located around 1040 cm(-1). The prediction errors range from 0.8 to 2.1 mueq, which, under the specific experimental conditions, corresponds to approximately 2 to 6 ppm N-NO(3)(-) on a solution basis or 2 to 5 mg [N]/kg [dry soil] on a dry soil basis. PMID:17002826

Linker, Raphael; Shaviv, Avi

2006-09-01

403

Nitrate therapy in heart failure.  

PubMed

Nitrates are drugs of first choice in patients with acute heart failure. Acute pulmonary edema can be successfully treated with single or repeated doses of sublingual nitroglycerin. In cases of prolonged acute heart failure, e.g. in the setting of acute myocardial infarction, nitroglycerin or isosorbide dinitrate can be given by the intravenous route for up to 24 h. Patients with acute myocardial infarction usually benefit from nitrate therapy if filling pressures are high and/or left ventricular function is compromised. Nitrate therapy can be considered safe if arterial blood pressure is maintained above 95 mm Hg. With these precautions nitrates can reduce infarct size and the incidence of complications as well as improve long-term prognosis. In the chronic treatment concern has risen with regard to possible nitrate tolerance. Thus, therapy schedules allowing for nitrate-poor phases are generally recommended. Therapy schedules with constant-rate delivery of drugs achieved with patches or intravenous administration of nitrates should be used with caution. PMID:1760830

Schneider, W; Bussmann, W D; Hartmann, A; Kaltenbach, M

1991-01-01

404

Nitrate Reductase from Squash: cDNA Cloning and Nitrate Regulation  

Microsoft Academic Search

The assimilation of nitrate in plants involves the reduction of nitrate to ammonia in two steps. The first step requires nitrate reductase, a nitrate-inducible enzyme. When seedlings of squash (Cucurbita maxima L.) were treated with nitrate, both nitrate reductase activity and protein were induced in the cotyledons. Poly(A)+ RNA was prepared from cotyledons of nitrate-treated seedlings and was used to

Nigel M. Crawford; Wilbur H. Campbell; Ronald W. Davis

1986-01-01

405

PROCESS FOR SEGREGATING URANIUM FROM PLUTONIUM AND FISSION-PRODUCT CONTAMINATION  

DOEpatents

An aqueous nitric acid solution containing uranium, plutonium, and fission product values is contacted with an organic extractant comprised of a trialkyl phosphate and an organic diluent. The relative amounts of trialkyl phosphate and uranium values are controlled to achieve a concentration of uranium values in the organic extractant of at least 0.35 moles uranium per mole of trialkyl phosphate, thereby preferentially extracting uranium values into the organic extractant.

Ellison, C.V.; Runion, T.C.

1961-06-27

406

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

407

Determination of soluble styphnate and nitrate in waste-water from lead styphnate primer plants.  

PubMed

Methods are proposed for the determination of soluble styphnate and nitrate in waste-water from lead styphnate primer plants. The styphnate is extracted from the waste-water with methylene chloride and is determined by measurement of the absorbance of the methylene chloride solution at 273 nm. The nitrate is determined in the aqueous solution left after the methylene extraction by measurement of the absorbance at 220 nm. For complete extraction of the styphnate by the methylene chloride, the solution must be moderately acidic (about 6% perchloric acid). The acidity for the determination of the nitrate is not critical. Before the determination of the nitrate in the aqueous extract, it is necessary to boil the solution to eliminate residual methylene chloride which would interfere with the determination of nitrate. PETN is extracted by the methylene chloride but does not interfere with the determination of the styphnate, since it shows no interfering peaks. Chloride, sulphate, phosphate, fluoride and carbonate do not interfere with the determination of styphnate or nitrate. PMID:18961692

Norwitz, G; Gordon, H

1975-07-01

408

Criticality data and validation studies of mixed-oxide fuel pin arrays in Pu+U+Gd nitrate  

Microsoft Academic Search

Critical experiments were performed at the Pacific Northwest Laboratory's Critical Mass Laboratory in 1987 and 1988 with a heterogeneous array of mixed-oxide (MOX) fuel pins immersed in mixed plutonium-uranium nitrate solutions. The 996 fuel pins, on a 1.40-cm-square pitch, were configured in a cylindrical array. The solution heavy metal concentrations ranged from 4 to 468 g\\/[ell] and had a Pu\\/Pu

G. R. Smolen; R. C. Lloyd; Tadakuni Matsumoto

1994-01-01

409

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

National Technical Information Service (NTIS)

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 de...

R. D. Scheele T. D. Cooper S. A. Jones J. R. Ewalt J. A. Compton D. S. Trent M. K. Edwards A. E. Kozelisky P. A. Scott M. J. Minette

2005-01-01

410

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

Technology Transfer Automated Retrieval System (TEKTRAN)

Slow release nitrogen (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 conventional aqueous urea-ammonium nitrate (UAN) [(NH2)2CO, NH4NO3]...

411

Comparative ease of separation of mixtures of selected nuisance anions (nitrate, nitrite, sulfate, phosphate) using Octolig®  

Microsoft Academic Search

Mixtures of sodium salts of nitrate, nitrite, sulfate, and phosphate were prepared in relative amounts present in atomic waste containers with a view to effect removal by chromatography over Octolig®, commercially available material with polyethylenediamine moieties covalently attached to high-surface area silica gel. Separation was attempted using aqueous solutions and column chromatography with Octolig®. It is presumed that this material

Frederick W. Stull; Dean F. Martin

2009-01-01

412

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.

1993-01-01

413

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

414

Phase equilibria and critical phenomena in the potassium nitrate-water-diethylamine ternary system  

NASA Astrophysics Data System (ADS)

Phase equilibria and critical phenomena in the potassium nitrate-water-diethylamine ternary system were studied by the visual polythermal method over the temperature range 40 150°C. The corresponding boundary binary liquid system was characterized by stratification with the lower critical temperature of solution. The introduction of potassium nitrate into the water-diethylamine system lowered its lower critical temperature of solution from 146.1 to 48.1°C and decreased the mutual solubility of the components. The diethylamine distribution coefficients between the aqueous and organic monotectic equilibrium phases at various temperatures were calculated. The effect of the salting out of diethylamine from aqueous solutions under the action of potassium nitrate was found to strengthen as the temperature increased. The constructed isotherms of the phase states of the system substantiated the generalized topological scheme of the transformation of phase diagrams of salt-binary solvent ternary systems with salting out.

Il'in, K. K.; Kurskii, V. F.; Cherkasov, D. G.; Sinegubova, S. I.

2008-03-01

415

Draft Guidance on Miconazole Nitrate  

Center for Biologics Evaluation and Research (CBER)

Text Version... Draft Guidance on Miconazole Nitrate This draft guidance, once finalized, will represent the Food and Drug Administration's (FDA's) current thinking ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

416

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

417

Modeling of distribution and speciation of plutonium in the Urex extraction system  

SciTech Connect

The PUREX extraction process is used worldwide to recover uranium and plutonium from dissolved spent nuclear fuel using the tributylphosphate-nitric acid extraction system. In the recent decade, significant research progress was achieved with the aim to modify this system by addition of a salt-free agent to optimize stripping of plutonium from the tributylphosphate (TBP) extraction product (UREX). Experimental results on the extraction of Pu(IV) with and without acetohydroxamic acid in the HNO{sub 3}/TBP (30 vol %) were used for the development of a thermodynamic model of distribution and speciation of Pu(IV) in this separation process. Extraction constants for several sets of nitric acid, nitrate, and acetohydroxamic acid concentrations were used to model the obtained data. The extraction model AMUSE (Argonne Model for Universal Solvent Extraction) was employed in our calculations. (authors)

Paulenova, A.; Tkac, P. [Radiation Center, Oregon State University, Corvallis, OR 97331-5903 (United States); Vandegrift, G.F.; Krebs, J.F. [Argonne National Laboratory, Chemical Sciences and Engineering Division, Argonne, IL 60439-4837 (United States)

2008-07-01

418

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

419

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

420

Surprising coordination for plutonium in the first plutonium(III) borate.  

PubMed

The first plutonium(III) borate, Pu(2)[B(12)O(18)(OH)(4)Br(2)(H(2)O)(3)]·0.5H(2)O, has been prepared by reacting plutonium(III) with molten boric acid under strictly anaerobic conditions. This compound contains a three-dimensional polyborate network with triangular holes that house the plutonium(III) sites. The plutonium sites in this compound are 9- and 10-coordinate and display atypical geometries. PMID:21341700

Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

2011-02-22

421

PRECIPITATION METHOD FOR THE SEPARATION OF PLUTONIUM AND RARE EARTHS  

DOEpatents

A method of purifying plutonium is given. Tetravalent plutonium is precipitated with thorium pyrophosphate, the plutonium is oxidized to the tetravalent state, and then impurities are precipitated with thorium pyrophosphate.

Thompson, S.G.

1960-04-26

422

10 CFR 71.63 - Special requirement for plutonium shipments.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Special requirement for plutonium shipments. 71.63 Section 71.63...Standards § 71.63 Special requirement for plutonium shipments. Shipments containing plutonium must be made with the contents in...

2013-01-01

423

Thermodynamic quantities of surface formation of aqueous electrolyte solutions  

Microsoft Academic Search

In this work the surface tension of the aqueous solutions of alkali metal sulfate, magnesium sulfate, and magnesium nitrate have been measured with an expectation that the effect of sulfate salts on the air\\/water surface differs from that of typical electrolyte because of their peculiar results of surface potential data. The results show that the slope of surface tension–concentration curves

Norihiro Matubayasi; Susumu Tsuchihashi; Ryuji Yoshikawa

2009-01-01

424

Multi-generational stewardship of plutonium  

SciTech Connect

The post-cold war era has greatly enhanced the interest in the long-term stewardship of plutonium. The management of excess plutonium from proposed nuclear weapons dismantlement has been the subject of numerous intellectual discussions during the past several years. In this context, issues relevant to long-term management of all plutonium as a valuable energy resource are also being examined. While there are differing views about the future role of plutonium in the economy, there is a recognition of the environmental and health related problems and proliferation potentials of weapons-grade plutonium. The long-term management of plutonium as an energy resource will require a new strategy to maintain stewardship for many generations to come.

Pillay, K.K.S. [Los Alamos National Lab., NM (United States). Nuclear Materials Technology Div.

1997-10-01

425

SEPARATION OF PLUTONIUM HYDROXIDE FROM BISMUTH HYDROXIDE  

DOEpatents

An tmproved method is described for separating plutonium hydroxide from bismuth hydroxide. The end product of the bismuth phosphate processes for the separation amd concentration of plutonium is a inixture of bismuth hydroxide amd plutonium hydroxide. It has been found that these compounds can be advantageously separated by treatment with a reducing agent having a potential sufficient to reduce bismuth hydroxide to metalltc bisinuth but not sufficient to reduce the plutonium present. The resulting mixture of metallic bismuth and plutonium hydroxide can then be separated by treatment with a material which will dissolve plutonium hydroxide but not metallic bismuth. Sodiunn stannite is mentioned as a preferred reducing agent, and dilute nitric acid may be used as the separatory solvent.

Watt, G.W.

1958-08-19

426

Photosynthetic nitrate assimilation in cyanobacteria.  

PubMed

Nitrate uptake and reduction to nitrite and ammonium are driven in cyanobacteria by photosynthetically generated assimilatory power, i.e., ATP and reduced ferredoxin. High-affinity nitrate and nitrite uptake takes place in different cyanobacteria through either an ABC-type transporter or a permease from the major facilitator superfamily (MFS). Nitrate reductase and nitrite reductase are ferredoxin-dependent metalloenzymes that carry as prosthetic groups a [4Fe-4S] center and Mo-bis-molybdopterin guanine dinucleotide (nitrate reductase) and [4Fe-4S] and siroheme centers (nitrite reductase). Nitrate assimilation genes are commonly found forming an operon with the structure: nir (nitrite reductase)-permease gene(s)-narB (nitrate reductase). When the cells perceive a high C to N ratio, this operon is transcribed from a complex promoter that includes binding sites for NtcA, a global nitrogen-control regulator that belongs to the CAP family of bacterial transcription factors, and NtcB, a pathway-specific regulator that belongs to the LysR family of bacterial transcription factors. Transcription is also affected by other factors such as CnaT, a putative glycosyl transferase, and the signal transduction protein P(II). The latter is also a key factor for regulation of the activity of the ABC-type nitrate/nitrite transporter, which is inhibited when the cells are incubated in the presence of ammonium or in the absence of CO(2). Notwithstanding significant advance in understanding the regulation of nitrate assimilation in cyanobacteria, further post-transcriptional regulatory mechanisms are likely to be discovered. PMID:16143847

Flores, Enrique; Frías, José E; Rubio, Luis M; Herrero, Antonia

2005-01-01

427

Analysis of nitrate in food extracts using a thermostable formate linked nitrate reductase enzyme system  

Microsoft Academic Search

A method for reduction of nitrate to nitrite for determination of nitrate is described, using a thermostable formate linked nitrate reductase enzyme system (FLNR). The reduction of nitrate to nitrite was found to be quantitative in water and in various food samples containing nitrate. The method is suggested as an alternative for the cadmium reduction method.

Sigurður Baldursson; Jakob K. Kristjánsson

1990-01-01

428

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

429

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

430

Fabrication of Fuel Pellets from Plutonium Dioxide  

Microsoft Academic Search

Fuel based on plutonium dioxide, which is sintered at high temperature and is produced at the Industrial Association Mayak, is supposed to be investigated in an upgraded IBR-2M reactor (Joint Institute of Nuclear Research). Oxalate precipitation of plutonium dioxide powder is done from a nitric-acid solution of plutonium with concentration from 7 to 24 g\\/liter. The oxalate hexahydrate Pu(C 2

A. I. Bobylev; S. N. Elsukov; S. I. Rovnyi; I. V. Manakov; A. V. Kobyakov; M. V. Pechenkina

2004-01-01

431

PROCESS FOR THE RECOVERY OF PLUTONIUM  

DOEpatents

A process for the separation of plutonium from uranlum and other associated radioactlve fission products ls descrlbed conslstlng of contacting an acid solution containing plutonium in the tetravalent state and uranium in the hexavalent state with enough ammonium carbonate to form an alkaline solution, adding cupferron to selectlvely form plutonlum cupferrlde, then recoverlng the plutonium cupferride by extraction with a water lmmiscible organic solvent such as chloroform.

Potratz, H.A.

1958-12-16

432

Air transport of plutonium metal : content expansion initiative for the Plutonium Air Transportable (PAT1) packaging  

Microsoft Academic Search

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

Paul T. Mann; Michael L. Caviness; Richard Hiroyuki Yoshimura

2010-01-01

433

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

Microsoft Academic Search

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

Michael L Caviness; Paul T Mann; Richard H Yoshimura

2010-01-01

434

Phase equilibria and salting-out effects in a cesium nitrate-triethylamine-water system at 5-25°C  

NASA Astrophysics Data System (ADS)

Phase equilibria and critical phenomena in a cesium nitrate-water-triethylamine system in which the constituent binary liquid system is stratified at the lower critical solution temperature (LCST) is studied in a range of 5-25°C by the visual polythermal method. It is found that introducing cesium nitrate into the water-triethylamine system leads to a slight reduction in the LCST (from 18.3 to 16.3°C) and to a decrease in the mutual solubility of the components. The distribution coefficients of triethylamine between aqueous and the organic phases of the monotectic state at different temperatures are calculated. It is found that the salting-out of triethylamine from aqueous solutions by cesium nitrate increases with rising temperature. The results of the salting-out effect of sodium, potassium, and cesium nitrates on a water-triethylamine binary system are compared.

Il'in, K. K.; Cherkasov, D. G.

2013-04-01

435

Electrochemical investigation into the mechanism of plutonium reduction in electrorefining  

Microsoft Academic Search

Currently impure plutonium metal is purified at Los Alamos National Laboratory by a molten salt electrorefining process. Electrorefining is an effective method for producing high-purity plutonium metal (> 99.95%). In general this process involves the oxidation of impure plutonium metal from a molten plutonium anode or a solvent metal\\/plutonium anode, transport of plutonium ions through a molten salt electrolyte, and

L. E. McCurry; G. M. M. Moy

1987-01-01

436

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

437

The chlorination of plutonium dioxide  

Microsoft Academic Search

We investigated the conversion of PuOâ to PuClâ with a number of chlorinating agents, sources of PuOâ, and reaction conditions, including temperature. We examined Clâ, HCl, CClâ, Clâ-CClâ, and HCl-CClâ as potential chlorinating agents. Our study showed tyhat Clâ-CClâ was the superior chlorinating agent. Using this agent, low-fired PuOâ--formed by calcining plutonium (III) oxalate at temperatures below 500\\/degree\\/C--is more reactive

C. Snyder; M. H. West; M. D. Ferran; K. W. Fife

1988-01-01

438

Plutonium transmutation in thorium fuel cycle  

SciTech Connect

The HELIOS spectral code was used to study the application of the thorium fuel cycle with plutonium as a supporting fissile material in a once-through scenario of the light water reactors PWR and VVER-440 (Russian design). Our analysis was focused on the plutonium transmutation potential and the plutonium radiotoxicity course of hypothetical thorium-based cycles for current nuclear power reactors. The paper shows a possibility to transmute about 50% of plutonium in analysed reactors. Positive influence on radiotoxicity after 300 years and later was pointed out. (authors)

Necas, Vladimir [Slovak University of Technology, Faculty of Electrical Engineering and Information Technology, Department of Nuclear Physics and Technology, Ilkovicova 3, SK-812 19 Bratislava (Slovakia); Breza, Juraj [Slovak University of Technology, Faculty of Electrical Engineering and Information Technology, Department of Nuclear Physics and Technology, Ilkovicova 3, SK-812 19 Bratislava (Slovakia)]|[VUJE, Inc., Okruzna 5, SK-918 64 Trnava (Slovakia); Darilek, Petr [VUJE, Inc., Okruzna 5, SK-918 64 Trnava (Slovakia)

2007-07-01

439

METHOD OF REDUCING PLUTONIUM WITH FERROUS IONS  

DOEpatents

A process is presented for separating hexavalent plutonium from fission product values. To a nitric acid solution containing the values, ferrous ions are added and the solution is heated and held at elevated temperature to convert the plutonium to the tetravalent state via the trivalent state and the plutonium is then selectively precipitated on a BiPO/sub 4/ or LaF/sub 3/ carrier. The tetravalent plutonium formed is optionally complexed with fluoride, oxalate, or phosphate anion prior to carrier precipitation.

Dreher, J.L.; Koshland, D.E.; Thompson, S.G.; Willard, J.E.

1959-10-01

440

Assay of low-level plutonium effluents  

SciTech Connect

In the plutonium recovery section at the Los Alamos National Laboratory, an effluent solution is generated that contains low plutonium concentration and relatively high americium concentration. Nondestructive assay of this solution is demonstrated by measuring the passive L x-rays following alpha decay. Preliminary results indicate that an average deviation of 30% between L x-ray and alpha counting can be achieved for plutonium concentrations above 10 mg/L and Am/Pu ratios of up to 3; for plutonium concentrations less than 10 mg/L, the average deviation is 40%. The sensitivity of the L x-ray assay is approx. 1 mg Pu/L.

Hsue, S.T.; Hsue, F.; Bowersox, D.F.

1981-01-01

441

Solubility of tributyl phosphate and its degradation products in concentrated uranyl nitrate solutions and of uranyl nitrate in tributyl phosphate at elevated temperatures  

Microsoft Academic Search

Solubility of UO2(NO3)2, TBP, and its degradation products in the organic and aqueous phases of the system TPB-H2O-HNO3-UO2(NO3)2 at 25–128°C over the uranyl nitrate concentration range 200–1200 g 1-1 is studied. The solubility of TBP and its degradation products in uranyl nitrate hexahydrate melt decreases in the order H2MBP > HDBP > TBP > H3PO4. At the boiling point of

V. N. Usachev; G. S. Markov

2004-01-01

442

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

443

Uptake and translocation of plutonium in two plant species using hydroponics  

Microsoft Academic Search

This study presents determinations of the uptake and translocation of Pu in Indian mustard (Brassica juncea) and sunflower (Helianthus annuus) from Pu contaminated solution media. The initial activity levels of Pu were 18.50 and 37.00 Bq ml?1 for Pu-nitrate [239Pu(NO3)4] and for Pu-citrate [239Pu(C6H5O7)+] in nutrient solution. Plutonium-diethylenetriaminepentaacetic acid (DTPA; [239Pu-C14H23O10N3] solution was prepared by adding 0, 5, 10, and

J. H Lee; L. R Hossner; M Attrep Jr; K. S Kung

2002-01-01

444

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

445

Effect of nitrate pulses on the nitrate-uptake rate, synthesis of mRNA coding for nitrate reductase, and nitrate-reductase activity in the roots of barley seedlings  

Microsoft Academic Search

Using pulses of nitrate, instead of the permanent presence of external nitrate, to induce the nitrate-assimilating system in Hordeum vulgare L., we demonstrated that nitrate can be considered as a trigger or signal for the induction of nitrate uptake, the appearance of nitratereductase activity and the synthesis of mRNA coding for nitrate reductase. Nitrate pulses stimulated the initial rate of

Rudolf Tischner; Barbara Waldeck; Sham S. Goyal; William D. Rains

1993-01-01

446

Development program to recycle and purify plutonium-238 oxide fuel from scrap  

SciTech Connect

Nuclear Materials Technology (NMT) Division has initiated a development program to recover and purify plutonium-238 oxide from impure sources. A glove box line has been designed and a process flowsheet developed to perform this task on a large scale. The initial effort has focused on purification of {sup 238}PuO{sub 2} fuel that fails to meet General Purpose Heat Source (GPHS) specifications because of impurities. The notable non-actinide impurities were silicon and phosphorus, but aluminum, chromium, iron and nickel were also near or in excess of limits specified by GPHS fuel powder specifications. Among actinide impurities, uranium is of paramount concern because {sup 234}U is the daughter of {sup 2238}Pu by alpha decay, and is the largest actinide impurity. An aqueous method based on nitric acid was selected for purification of the {sup 238}PuO{sub 2} fuel. All aqueous processing used high purity reagents, and was performed in PTFE apparatus to minimize introduction of new contaminants. Impure {sup 238}PuO{sub 2} was first dissolved in refluxing HNO{sub 3}/HF and then the solution was filtered. The dissolved {sup 238}Pu was adjusted to the trivalent state by an excess of reducing reagents to compensate for radiolytic effects, precipitated as plutonium(III) oxalate, and recovered by filtration. The plutonium(III) oxalate was subsequently calcined to convert the plutonium to the oxide. Decontamination factors for silicon, phosphorus and uranium were excellent. Decontamination factors for aluminum, chromium, iron and nickel were very good. The purity of the {sup 238}PuO{sub 2} recovered from this operation was significantly better than specifications. Efforts continue to develop the capability for efficient, safe, cost-effective, and environmentally acceptable methods to recover and purify {sup 238}PuO{sub 2} fuel in a glovebox environment. Plutonium-238 materials targeted for recovery includes impure oxide and scrap items that are lean in {sup 238}Pu values.

Schulte, L.D.; Silver, G.L.; Avens, L.R.; Jarvinen, G.D.; Espinoza, J.; Foltyn, E.M.; Rinehart, G.H.

1996-12-31

447

Development program to recycle and purify plutonium-238 oxide fuel from scrap  

NASA Astrophysics Data System (ADS)

Nuclear Materials Technology (NMT) Division of Los Alamos National Laboratory (LANL) has initiated a development program to recover & purify plutonium-238 oxide from impure sources. A glove box line has been designed and a process flowsheet developed to perform this task on a large scale. Our initial effort has focused on purification of 238PuO2 fuel that fails to meet General Purpose Heat Source (GPHS) specifications because of impurities. The most notable non-actinide impurity was silicon, but aluminum, chromium, iron and nickel were also near or in excess of limits specified by GPHS fuel powder specifications. 234U was by far the largest actinide impurity observed in the feed material because it is the daughter product of 238Pu by alpha decay. An aqueous method based on nitric acid was selected for purification of the 238PuO2 fuel. All aqueous processing used high purity reagents, and was performed in PTFE apparatus to minimize introduction of new contaminants. Impure 238PuO2 was finely milled, then dissolved in refluxing HNO3/HF and the solution filtered. The dissolved 238Pu was adjusted to the trivalent state by an excess of reducing reagents to compensate for radiolytic effects, precipitated as plutonium(III) oxalate, and recovered by filtration. The plutonium(III) oxalate was subsequently calcined to convert the plutonium to the oxide. Decontamination factors for silicon, phosphorus and uranium were excellent. Decontamination factors for aluminum, chromium, iron and nickel were very good. The purity of the 238PuO2 recovered from this operation was significantly better than specifications. Efforts continue to develop the capability for efficient, safe, cost-effective, and environmentally acceptable methods to recover and purify 238PuO2 fuel in a glove box environment. Plutonium-238 materials targeted for recovery includes impure oxide and scrap items that are lean in 238Pu values.

Schulte, Louis D.; Silver, Gary L.; Avens, Larry R.; Jarvinen, Gordon D.; Espinoza, Jacob; Foltyn, Elizabeth M.; Rinehart, Gary H.

1997-01-01

448

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

449

Radiochemical studies on the isotope plutonium-241  

Microsoft Academic Search

A large number of plutonium isotopes have been prepared and studied during the course of the Manhattan project and subsequent operations. Plutonium isotopes from mass 232 to 243 have been characterized and their radiations measured. Of these isotopes, the group of mass 238 to 242 are of particular importance due to their production in appreciable quantities by neutron irradiation of

Chetham-Brode

1953-01-01

450

The Electrochromatography of Seawater Containing Dissolved Plutonium.  

National Technical Information Service (NTIS)

Electrochromatographic techniques were used to determine the chemical form of plutonium in seawater. If either Pu (III), Pu (IV) or PuO2(++) was added to a 0.7M NaCl-0.0023 M Na2CO3 solution, it was found that in each case about 30% of the plutonium would...

W. E. Lingren

1966-01-01

451

Plutonium Immobilization Project -- Robotic canister loading  

Microsoft Academic Search

The Plutonium Immobilization Program (PIP) is a joint venture between the Savannah River Site (SRS), Lawrence Livermore National Laboratory (LLNL), Argonne National Laboratory (ANL), and Pacific Northwest National Laboratory (PNNL). 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 and making it unattractive for reuse. Since

2000-01-01

452

Corrosion of delta Plutonium by Water.  

National Technical Information Service (NTIS)

Corrosion of delta-stabilized (1 wt % Ga) WR plutonium was studied in water, synthetic sea water, tap water, and distilled water. The product is a dark blue-green residue, suggesting a mixture of hydrated trivalent and tetravalent plutonium hydroxides. Th...

A. E. Hodges J. M. Haschke

1979-01-01

453

Burning weapons-grade plutonium in reactors  

Microsoft Academic Search

As a result of massive reductions in deployed nuclear warheads, and their subsequent dismantlement, large quantities of surplus weapons- grade plutonium will be stored until its ultimate disposition is achieved in both the US and Russia. Ultimate disposition has the following minimum requirements: (1) preclude return of plutonium to the US and Russian stockpiles, (2) prevent environmental damage by precluding

1993-01-01

454

Plutonium Immobilization Program: Can-in-Canister  

SciTech Connect

'The end of the cold war brought about a potential new danger, the existence of surplus weapons grade plutonium in the U.S. and Russia. Bilateral disposition programs provide the preferred long-term solution. This paper presents an overview of the U.S. approach to plutonium immobilization using the Can-in-Canister technology.'

Rankin, D.T.

1999-07-14

455

Surplus Plutonium Disposition Final Environmental Impact Statement  

SciTech Connect

In December 1996, the U.S. Department of Energy (DOE) published the ''Storage and Disposition of Weapons-Usable Fissile Materials Final Programmatic Environmental Impact Statement (Storage and Disposition PEIS)'' (DOE 1996a). That PEIS analyzes the potential environmental consequences of alternative strategies for the long-term storage of weapons-usable plutonium and highly enriched uranium (HEU) and the disposition of weapons-usable plutonium that has been or may be declared surplus to national security needs. The Record of Decision (ROD) for the ''Storage and Disposition PEIS'', issued on January 14, 1997 (DOE 1997a), outlines DOE's decision to pursue an approach to plutonium disposition that would make surplus weapons-usable plutonium inaccessible and unattractive for weapons use. DOE's disposition strategy, consistent with the Preferred Alternative analyzed in the ''Storage and Disposition PEIS'', allows for both the immobilization of some (and potentially all) of the surplus plutonium and use of some of the surplus plutonium as mixed oxide (MOX) fuel in existing domestic, commercial reactors. The disposition of surplus plutonium would also involve disposal of both the immobilized plutonium and the MOX fuel (as spent nuclear fuel) in a potential geologic repository.

N /A

1999-11-19

456

49 CFR 175.704 - Plutonium shipments.  

Code of Federal Regulations, 2012 CFR

...aboard the aircraft on the main deck or the lower cargo compartment in the aft-most location that is possible for cargo of its size and weight, and no other cargo may be stowed aft of packages containing plutonium. (c) A package of plutonium...

2012-10-01

457

49 CFR 175.704 - Plutonium shipments.  

Code of Federal Regulations, 2011 CFR

...aboard the aircraft on the main deck or the lower cargo compartment in the aft-most location that is possible for cargo of its size and weight, and no other cargo may be stowed aft of packages containing plutonium. (c) A package of plutonium...

2011-10-01

458

The hydrofluorination of uranium and plutonium  

NASA Astrophysics Data System (ADS)

The preparation of uranium and plutonium deposits by vacuum deposition of their fluorides has a number of advantages over other methods, but requires anhydrous fluorides, which are preferably prepared using the dry hydrofluorination process. However this process depends on the way the starting materials have been prepared. Both for uranium and plutonium oxides preparation via the oxalate way is recommended.

Eykens, R.; Pauwels, J.; van Audenhove, J.

1985-06-01

459

MOLTEN PLUTONIUM FUELED FAST BREEDER REACTOR  

Microsoft Academic Search

A description is given of a nuclear fast reactor fueled with molten ; plutonium containing about 20 kg of plutonium in a tantalum container, cooled by ; circulating liquid sodium at about 600 to 650 deg C, having a large negative ; temperature coefficient of reactivity, and control rods and movable reflector for ; criticality control. (AEC)

R. M. Kiehn; L. D. P. King; R. E. Peterson; E. O. Jr. Swickard

1962-01-01

460

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

461

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

462

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

463

Impact of MCNP unresolved resonance probability-table treatment on uranium and plutonium benchmarks  

SciTech Connect

Versions of MCNP up through and including MCNP 4B have not accurately modeled neutron self-shielding effects in the unresolved resonance energy region. Recently, a probability-table treatment has been incorporated into a developmental version of MCNP. MCNP results are presented for a variety of uranium and plutonium critical benchmarks, calculated with and without the probability-table treatment. The results from these calculations, along with their associated standard deviations, are presented. Four conclusions can be drawn from these results. First, not surprisingly, the only benchmarks that are substantially affected are those that have a significant fraction of their interactions within the unresolved resonance region of the principal uranium and plutonium isotopes that are present. For example, the unreflected metal spheres and the graphite-reflected IEU sphere have spectra that are too hard to produce large reactivity changes, while the fluoride and nitrate solutions have spectra that are too thermal. Second, the reactivity impact of the improvement is essentially negligible for {sup 235}U in these systems. The spectral peaks for all of the HEU benchmarks except GODIVA occur within the unresolved resonance region, but the probability-table treatment does not produce a statistically significant change in reactivity for any of them. Third, the probability-table method can produce substantial increases in reactivity for those benchmarks that include proportionately large amounts of {sup 238}U and high fluxes within the unresolved resonance region. Finally, the probability-table method also can produce significant reactivity changes for plutonium benchmarks with intermediate spectra. However, the magnitude of those changes is considerably smaller than for some of the cases with {sup 238}U. There are competing reactivity effects among the different plutonium isotopes, and in addition, the unresolved resonance range for the plutonium isotopes is not as broad as that for {sup 238}U.

Mosteller, R.D.; Little, R.C. [Los Alamos National Lab., NM (United States)

1998-12-31

464

Conversion of actinide and RE oxides into nitrates and their recovery into fluids  

SciTech Connect

The conditions for uranium oxides completely convert into uranyl nitrate hexahydrate in nitrogen tetra-oxide media (75 deg. C, 0,5-3,0 MPa, [UO{sub x}]:[H{sub 2}O]:[NO{sub 2}]=1:8:6) were found out. The conversion of Pu contained simulator of oxide spent nuclear fuel of thermal reactors was successfully demonstrated. The possibility of uranium recovery up to 95% from TR SNF without plutonium separation from FP is practically showed, what corresponds with Non-proliferation Treaty. (authors)

Bondin, V.V.; Bychkov, S.I.; Efremov, I.G.; Revenko, Y.A. [Mining Chemical Combine - MCC, 53 ul. Lenina, 662972, Zheleznogorsk (Russian Federation); Babain, V.A.; Murzin, A.A.; Romanovsky, V.N; Fedorov, Y.S.; Shadrin, A.Y.; Ryabkova, N.V.; Li, E.N. [Khlopin Radium Institute - KRI, 28, 2nd Murinsky ave, 194021, St. Petersburg (Russian Federation)

2007-07-01

465

Treatment of plutonium process residues by molten salt oxidation  

SciTech Connect

Molten Salt Oxidation (MSO) is a thermal process that can remove more than 99.999% of the organic matrix from combustible {sup 238}Pu material. Plutonium processing residues are injected into a molten salt bed with an excess of air. The salt (sodium carbonate) functions as a catalyst for the conversion of the organic material to carbon dioxide and water. Reactive species such as fluorine, chlorine, bromine, iodine, sulfur, phosphorous and arsenic in the organic waste react with the molten salt to form the corresponding neutralized salts, NaF, NaCl, NaBr, NaI, Na{sub 2}SO{sub 4}, Na{sub 3}PO{sub 4} and NaAsO{sub 2} or Na{sub 3}AsO4. Plutonium and other metals react with the molten salt and air to form metal salts or oxides. Saturated salt will be recycled and aqueous chemical separation will be used to recover the {sup 238}Pu. The Los Alamos National Laboratory system, which is currently in the conceptual design stage, will be scaled down from current systems for use inside a glovebox.

Stimmel, J.; Wishau, R.; Ramsey, K.B.; Montoya, A.; Brock, J. [Los Alamos National Lab., NM (United States); Heslop, M. [Naval Surface Warfare Center (United States). Indian Head Div.; Wernly, K. [Molten Salt Oxidation Corp. (United States)

1999-04-01

466

New Fecal Method for Plutonium and Americium  

SciTech Connect

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

Maxwell, S.L. III

2000-06-27

467

PROCESS FOR THE RECOVERY OF PLUTONIUM  

DOEpatents

An improvement is presented in the process for recovery and decontamination of plutonium. The carrier precipitate containing plutonium is dissolved and treated with an oxidizing agent to place the plutonium in a hexavalent oxidation state. A lanthanum fluoride precipitate is then formed in and removed from the solution to carry undesired fission products. The fluoride ions in the reniaining solution are complexed by addition of a borate sueh as boric acid, sodium metaborate or the like. The plutonium is then reduced and carried from the solution by the formation of a bismuth phosphate precipitate. This process effects a better separation from unwanted flssion products along with conccntration of the plutonium by using a smaller amount of carrier.

Ritter, D.M.

1959-01-13

468

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

469

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

470

Acetonyltriphenyl-phospho-nium nitrate.  

PubMed

Crystals of the title salt, C(21)H(20)OP(+)·NO(3) (-), are composed of acetonyltriphenyl-phospho-nium cations and nitrate anions that mainly inter-act through electrostatic forces. The P atom in the cation has a slightly distorted tetra-hedral 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. PMID:23424568

Diop, Tidiane; Diop, Libasse; Ku?eráková, Monika; Dušek, Michal

2013-01-31

471

ADSORPTION-BISMUTH PHOSPHATE METHOD FOR SEPARATING PLUTONIUM  

DOEpatents

A process is given for separating plutonium from uranium and fission products. Plutonium and uranium are adsorbed by a cation exchange resin, plutonium is eluted from the adsorbent, and then, after oxidation to the hexavalent state, the plutonium is contacted with a bismuth phosphate carrier precipitate.

Russell, E.R.; Adamson, A.W.; Boyd, G.E.

1960-06-28

472

Assessment of PWR plutonium burners for nuclear energy centers  

Microsoft Academic Search

The purpose of the study was to explore the performance and safety characteristics of PWR plutonium burners, to identify modifications to current PWR designs to enhance plutonium utilization, to study the problems of deploying plutonium burners at Nuclear Energy Centers, and to assess current industrial capability of the design and licensing of such reactors. A plutonium burner is defined to

A. J. Frankel; N. L. Shapiro

1976-01-01

473

Protection against oral and gastrointestinal diseases: Importance of dietary nitrate intake, oral nitrate reduction and enterosalivary nitrate circulation  

Microsoft Academic Search

Over the last 20 years, dietary nitrate has been implicated in the formation of methemoglobin and carcinogenic nitrosamines in humans. This has led to restrictions of nitrate and nitrite levels in food and drinking water. However, there is no epidemiological evidence for an increased risk of gastric and intestinal cancer in population groups with high dietary vegetable or nitrate intake.

Callum Duncan; Hong Li; Roelf Dykhuizen; Rennie Frazer; Peter Johnston; Gillian MacKnight; Lorna Smith; Kathryn Lamza; Hamish McKenzie; Les Batt; Denise Kelly; Michael Golden; Nigel Benjamin; Carlo Leifert

1997-01-01

474

Uptake, allocation and signaling of nitrate.  

PubMed

Plants need to acquire nitrogen (N) efficiently from the soil for growth. Nitrate is one of the major N sources for higher plants. Therefore, nitrate uptake and allocation are key factors in efficient N utilization. Membrane-bound transporters are required for nitrate uptake from the soil and for the inter- and intracellular movement of nitrate inside the plants. Four gene families, nitrate transporter 1/peptide transporter (NRT1/PTR), NRT2, chloride channel (CLC), and slow anion channel-associated 1 homolog 3 (SLAC1/SLAH), are involved in nitrate uptake, allocation, and storage in higher plants. Recent studies of these transporters or channels have provided new insights into the molecular mechanisms of nitrate uptake and allocation. Interestingly, several of these transporters also play versatile roles in nitrate sensing, plant development, pathogen defense, and/or stress response. PMID:22658680

Wang, Ya-Yun; Hsu, Po-Kai; Tsay, Yi-Fang

2012-05-31

475

21 CFR 172.170 - Sodium nitrate.  

Code of Federal Regulations, 2010 CFR

...ADDITION TO FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified foods in accordance with the following prescribed conditions: (a) It is used...

2009-04-01

476

21 CFR 172.170 - Sodium nitrate.  

Code of Federal Regulations, 2010 CFR

...ADDITION TO FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified foods in accordance with the following prescribed conditions: (a) It is used...

2010-01-01

477

BAM Media M101: Motility Nitrate Medium  

Center for Food Safety and Applied Nutrition (CFSAN)

... Food. ... Tryptose, 10 g. Heart infusion agar (Difco), 8 g. Potassium (or sodium) nitrate, 1 g. Glucose, 0.5 g. ... NOTE: Make sure nitrates are nitrite-free. ... More results from www.fda.gov/food/foodscienceresearch/laboratorymethods

478

21 CFR 172.160 - Potassium nitrate.  

Code of Federal Regulations, 2013 CFR

...CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing agent in the...

2013-04-01

479

Cryoscopic Studies of the Uranyl Sulfate–Water, Uranyl Nitrate–Water, and Uranyl Nitrate–Nitric Acid–Water Systems  

Microsoft Academic Search

Freezing point lowerings of aqueous solutions of uranyl sulfate in the concentration range m = 0.40 mol-kg-1 and the activity and osmotic coefficients, which were calculated using the Pitzer equations for 2:2 electrolytes, are presented. Crystallization temperatures are reported for 0 to 13 molar nitric acid and 10–150 g uranium per liter uranyl nitrate–nitric acid–water solutions.

Alexander Apelblat

1999-01-01

480