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1

Chromium in aqueous nitrate plutonium process streams: Corrosion of 316 stainless steel and chromium speciation  

SciTech Connect

According to the measurements made in this study, the only situation in which chromium (+6) could exist in a plutonium process solution is one in which a feed containing chromium is dissolved in a glass pot dissolver in high nitric acid concentration and at high temperature. But when the resulting feed is prepared for ion exchange, the chemical treatment reduces chromium to the +3 state. Any solution being processed through the evaporator will only contain chromium in the +3 state and any chromium salts remaining in the evaporator bottoms will be chromium +3 salts.

Smith, W.H.; Purdy, G.

1994-08-01

2

Production of Plutonium Metal from Aqueous Solutions  

SciTech Connect

The primary separation of plutonium from irradiated uranium by the Purex solvent extraction process at the Savannah River Plant produces a dilute plutonium solution containing residual fission products and uranium. A cation exchange process is used for concentration and further decontamination of the plutonium, as the first step in the final preparation of metal. This paper discusses the production of plutonium metal from the aqueous solutions.

Orth, D.A.

2003-01-16

3

PROCESS FOR EXTRACTING NEPTUNIUM AND PLUTONIUM FROM NITRIC ACID SOLUTIONS OF SAME CONTAINING URANYL NITRATE WITH A TERTIARY AMINE  

Microsoft Academic Search

A process of selectively extracting plutonium nitrate and neptunium ; nitrate with an organic solution of a tertiary amine, away from uranyl nitrate ; present in an aqueous solution in a maximum concentration of 1M is described. ; The nitric acid concentration is adjusted to about 4M and nitrous acid is added ; prior to extraction. (AEC)

Sheppard

1962-01-01

4

Quantitative description by means of linear free energy ratios of the effect of the aqueous phase concentration composition on extraction. IV. Extraction of tetravalent plutonium and neptunium from nitric acid solutions with amine nitrates  

Microsoft Academic Search

By means of a computer, a large mass of published data has been processed concerning the dependences of the distribution coefficients of tetravalent plutonium and neptunium between nitric acid aqueous solutions and extractants of the amine class, on the nitric acid concentration in the aqueous phase. More than 40 series of systems for plutonium and more than 20 for neptunium

E. A. Mezhov; V. N. Rubisov; V. N. Shesterikov; V. S. Shmidt

2009-01-01

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

Catalyzed reduction of nitrate in aqueous solutions  

SciTech Connect

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 advantageous for reduction of nitrate in sodium nitrate solutions. Objective of this seed money study was to determine minimum conditions for reduction. Proposed procedure was batchwise heating of aqueous solutions in closed vessels with monitoring of temperatures and pressures. A simple, convenient apparatus and procedure were demonstrated for observing formation of gaseous products and collecting samples for analyses. The test conditions were 250{degree}C and 1000 psi max. Any useful reduction of sodium nitrate to sodium hydroxide as the primary product was not found. The nitrate present at pHs < 4 as HNO{sub 3} or NH{sub 4}NO{sub 3} is easily decomposed, and the effect of nitromethane at these low pHs was confirmed. When acetic acid or formic acid was added, 21 to 56% of the nitrate in sodium nitrate solutions was reduced by methanol or formaldehyde. With hydrazine and acetic acid, 73 % of the nitrate was decomposed to convert NaNO{sub 3} to sodium acetate. With hydrazine and formic acid, 36% of the nitrate was decomposed. If these products are more acceptable for final disposal than sodium nitrate, the reagents are cheap and the conversion conditions would be practical for easy use. Ammonium acetate or formate salts did not significantly reduce nitrate in sodium nitrate solutions.

Haas, P.A.

1994-08-01

7

Exclusion of Nitrate from Frozen Aqueous Solutions  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

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

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

10

SULFATE AND NITRATE COATINGS ON MINERAL DUSTS: CRYSTALLINE OR AQUEOUS?  

E-print Network

SULFATE AND NITRATE COATINGS ON MINERAL DUSTS: CRYSTALLINE OR AQUEOUS? Scot T. Martin, Hui 02138, USA Keywords: Phase transition; Atmospheric Aerosols; Ammonium sulfate; Ammonium nitrate Observational evidence shows that mineral dusts in Asian outflows become coated by sulfates and nitrates. Layer

11

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

12

Chemical treatment of aqueous plutonium wastes  

Microsoft Academic Search

Chemical precipitation processes have been used for the removal of microconcentrations of Pu (approx. 4 nM to 4 ..mu..m) since the late 1940's; however, previous experiments have been empirically oriented. In order to provide a rational approach to the chemical treatment, aqueous Pu chemistry was reviewed to determine the species most likely to be present in alkaline conditions where chemical

Drago

1980-01-01

13

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

NASA Astrophysics Data System (ADS)

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

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

1999-10-01

14

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

15

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 fuel pins surrounded by plutonium-uranium nitrate solutions. The objectives of these experiments are to provide criticality data for a heterogeneous system of fuel pins moderated with plutonium-uranium solutions, 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. 4 refs., 1 fig., 1 tab.

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

1989-01-01

16

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

17

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

Microsoft Academic Search

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

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

2010-01-01

18

Supporting Information Nitrate Ions and Ion Pairing at the Air-Aqueous Interface  

E-print Network

1 Supporting Information Nitrate Ions and Ion Pairing at the Air-Aqueous Interface Man Xu, Cheng Y of the nitrate symmetric stretch peak as a function of molarity. Molarity units (dividing by volume) allows comparisons of transition moment strengths at different concentrations. Table S1. Nitrate concentrations

19

Aqueous polymer-nitrate solution deposition of YBCO films  

NASA Astrophysics Data System (ADS)

High critical current density YBa 2Cu 3O 7-x (YBCO) films were prepared by solution deposition of aqueous non-fluorine precursors. Non-fluorine polymer-assisted deposition (PAD) processes utilizing rheology modifiers and chelating agents were used to produce 50 nm films with a critical current density ( Jc) over 3 MA/cm 2 and 400 nm films with Jc > 1 MA/cm 2.Tc measurements indicated that films have Tc values near 90 K. The total heat treatment time to produce these high performance films was less than 4 h. Rheology modifiers such as polyvinyl alcohol (PVA) and hydroxyethyl cellulose (HEC) were used to increase the thickness of deposited films independent of the solution cation concentration. Chelating agents such as polyethylene glycol (PEG) and sucrose increased the barium ion solubility. Nitrate crystallization during deposition was controlled through rapid drying with vacuum and coating with hot solutions.

Patta, Y. R.; Wesolowski, D. E.; Cima, M. J.

2009-02-01

20

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

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

Characterization of aqueous silver nitrate solutions for leakage tests  

PubMed Central

Objectives To determine the pH over a period of 168 h and the ionic silver content in various concentrations and post-preparation times of aqueous silver nitrate solutions. Also, the possible effects of these factors on microleakage test in adhesive/resin restorations in primary and permanent teeth were evaluated. Material and Methods A digital pHmeter was used for measuring the pH of the solutions prepared with three types of water (purified, deionized or distilled) and three brands of silver nitrate salt (Merck, Synth or Cennabras) at 0, 1, 2, 24, 48, 72, 96 and 168 h after preparation, and storage in transparent or dark bottles. Ionic silver was assayed according to the post-preparation times (2, 24, 48, 72, 96, 168 h) and concentrations (1, 5, 25, 50%) of solutions by atomic emission spectrometry. For each sample of each condition, three readings were obtained for calculating the mean value. Class V cavities were prepared with enamel margins on primary and permanent teeth and restored with the adhesive systems OptiBond FL or OptiBond SOLO Plus SE and the composite resin Filtek Z-250. After nail polish coverage, the permanent teeth were immersed in 25% or 50% AgNO3 solution and the primary teeth in 5% or 50% AgNO3 solutions for microleakage evaluation. ANOVA and the Tukey's test were used for data analyses (?=5%). Results The mean pH of the solutions ranged from neutral to alkaline (7.9±2.2 to 11.8±0.9). Mean ionic silver content differed depending on the concentration of the solution (4.75±0.5 to 293±15.3 ppm). In the microleakage test, significant difference was only observed for the adhesive system factor (p=0.000). Conclusions Under the tested experimental conditions and based on the obtained results, it may be concluded that the aqueous AgNO3 solutions: have neutral/alkaline pH and service life of up to 168 h; the level of ionic silver is proportional to the concentration of the solution; even at 5% concentration, the solutions were capable of indicating loss of marginal seal in the composite restorations; the 3-step conventional adhesive system had better performance regarding microleakage in enamel on primary and permanent teeth. PMID:21625743

COSTA, José Ferreira; SIQUEIRA, Walter Luiz; LOGUERCIO, Alessandro Dourado; REIS, Alessandra; de OLIVEIRA, Elizabeth; ALVES, Cláudia Maria Coelho; BAUER, José Roberto de Oliveira; GRANDE, Rosa Helena Miranda

2011-01-01

23

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

24

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

25

VIBRATIONAL SUM FREQUENCY AND RAMAN SPECTROSCOPIC STUDIES OF AIR-AQUEOUS INTERFACES AND SOLUTIONS OF NITRATE SALTS, AND  

E-print Network

OF NITRATE SALTS, AND AIR-SILICA SURFACE ADSORPTION STUDIES DISSERTATION Presented in Partial Fulfillment Nitrate ions are ubiquitous in aqueous-phase atmospheric aerosols as well as surface and ground waters understanding of nitrate ions at the air- aqueous interface is of prime importance with respect to understanding

26

Extraction of trivalent rare-earth metal nitrates from concentrated aqueous salt solutions by triisoamyl phosphate  

Microsoft Academic Search

Equations are proposed for describing isotherms of extraction of trivalent rare earth metal nitrates from concentrated aqueous salt solutions by neat triisoamyl phosphate, which allow for variations in the activity coefficients of the components in organic phase over a wide range of its compositions. The phase extraction constants have been determined, with a hypothetical 1 mol kg⁻¹ aqueous solution of

A. K. Pyartman; V. A. Keskinov; E. A. Puzikov

1995-01-01

27

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

28

Criticality experiments with mixed plutonium-uranium nitrate solution at plutonium fraction of 0. 5, 0. 4, and 0. 2 in slab and cylindrical geometry  

SciTech Connect

The objective of these experiments is to provide criticality data for (Pu + U) solutions for use in optimizing the physical size of equipment used in nuclear reprocessing plants. Prior to these measurements, little criticality data were available for mixed plutonium-uranium solutions in slab and cylindrical geometry. 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 of the Pacific Northwest Laboratory. Criticality measurements were made with (Pu + U) nitrate solutions in slab and cylindrical geometry. The concentration of (Pu + U) in the nitrate solution was varied and ranged between 105 and 468 g (Pu + U)/l. The ratio of plutonium to (Pu + U) in the solution also was varied with measurements being made at 0.5, 0.4, and 0.2.

Lloyd, R.C.; Funabashi, H.

1988-01-01

29

Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions  

E-print Network

1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Plutonium by Controlled-Potential Coulometry Plutonium by Amperometric Titration with Iron(II) Plutonium by Diode Array Spectrophotometry Free Acid by Titration in an Oxalate Solution 8 to 15 Free Acid by Iodate Precipitation-Potentiometric Titration Test Method 16 to 22 Uranium by Arsenazo I Spectrophotometric Test Method 23 to 33 Thorium by Thorin Spectrophotometric Test Method 34 to 42 Iron by 1,10-Phenanthroline Spectrophotometric Test Method 43 to 50 Impurities by ICP-AES Chloride by Thiocyanate Spectrophotometric Test Method 51 to 58 Fluoride by Distillation-Spectrophotometric Test Method 59 to 66 Sulfate by Barium Sulfate Turbidimetric Test Method 67 to 74 Isotopic Composition by Mass Spectrom...

American Society for Testing and Materials. Philadelphia

2010-01-01

30

Method of separating thorium from plutonium  

DOEpatents

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

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

1984-07-10

31

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

32

Nitrates  

MedlinePLUS

... prescription instructions. Why do I need to take nitrates? Nitrates are used to treat the chest pain associated ... symptoms of congestive heart failure (CHF) . How do nitrates work? Nitrates are a vasodilator . Vasodilators widen (dilate) ...

33

Fission rate measurements at the vessel/reflector interface of a dilute plutonium-uranium nitrate solution in cylindrical geometry  

SciTech Connect

As part of the Criticality Data Development Program between the US Dept. of Energy (DOE) and the Power Reactor and Nuclear Fuel Development Corporation of Japan, neutron reaction rate measurements are being made on selected critical assemblies at the DOE Hanford Critical Mass Laboratory. Fission rate measurements made on the surface of a large water-reflected cylinder of plutonium-uranium nitrate solution are presented.

Bierman, S.R.; Fukumura, N.

1987-01-01

34

Removal of nitrate from aqueous solution using cetylpyridinium bromide (CPB) modified zeolite as adsorbent.  

PubMed

Surfactant modified zeolites (SMZ) with different coverage types were prepared by loading the cetylpyridinium bromide (CPB) onto the surface of the natural zeolites. The adsorption behavior of nitrate on SMZ was investigated. Natural zeolite and SMZ with monolayer CPB coverage were inefficient for the removal of nitrate from aqueous solution. However, SMZ with patchy bilayer or bilayer CPB coverage was efficient in nitrate removal, and the nitrate adsorption capacity of SMZ increased with its CPB loading. For typical SMZ with bilayer CPB coverage, the nitrate adsorption process was well described by the pseudo-second-order kinetic model, and the experimental isotherm data fitted well with the Langmuir, Freundlich and Dubinin-Redushkevich isotherm models. Thermodynamic parameters such as Gibbs free energy change, enthalpy change and entropy change were calculated and the results showed that the adsorption of nitrate on SMZ was spontaneous and exothermic in nature. The presence of competing anions such as chloride, sulfate and bicarbonate ions slightly reduced the nitrate adsorption efficiency. Anionic exchange and electrostatic interaction were proven to be the main mechanisms that govern the adsorption of nitrate on SMZ. PMID:21237561

Zhan, Yanhui; Lin, Jianwei; Zhu, Zhiliang

2011-02-28

35

Criticality data and validation studies of plutonium-uranium nitrate solutions in cylindrical and slab geometry  

SciTech Connect

A series of critical experiments was performed with mixed plutonium-uranium nitrate solutions in two cylinders and in a variable thickness slab tank. The solution concentrations ranged from 12 to 174 g Pu/[ell] with Pu/Pu+U ratios of 0.5, 0.4, and 0.2. The criticality data were used to validate two versions of the SCALE computer code system (SCALE-4 and SCALE-2). Calculations were performed with the 27-energy-group cross-section library, derived form the Evaluated Nuclear Data File B-Version IV. The average calculated k[sub eff] for all geometries (39 experiments) is 1.006 ([sigma] = 0.006), calculated with SCALE-4, and 1.004 ([sigma] = 0.007), calculated with SCALE-2. Overall, the range of calculated k[sub eff] varied from 0.989 to 1.019. These experiments covered a wide range of parameters, with variations in physical chemical, and neutronic parameters.

Smolen, G.R. (Oak Ridge National Lab., TN (United States). Computing and Telecommunications Div.); Lloyd, R.C. (Pacific Northwest Lab., Richland, WA (United States)); Funabashi, Hideyuki (Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan))

1994-09-01

36

Density and Sound Velocity Studies of Aqueous Solutions of Tetradecyltrimethylammonium Nitrate at Different Temperatures  

Microsoft Academic Search

The density and ultrasound velocity of aqueous solutions of tetradecyltrimethylammonium nitrate were measured in the temperature range of 15 to 35°C in 5°C intervals. The concentration range covered the premicellar and micellar regimes. By assuming a pseudophase separation model for the micellar system, we applied the densitometric data to estimate the apparent molar volumes and the apparent thermal expansibility coefficients

J. J. Galán; J. L. Del Castillo; A. González-Pérez; J. Czapkiewicz; J. R. Rodríguez

2003-01-01

37

Electrosurface properties of microcrystalline cellulose dispersions in aqueous solutions of aluminum chloride, nitrate, and sulfate  

Microsoft Academic Search

The method of microelectrophoresis is employed to study the dependence of the ?-potential of microcrystalline cellulose particles\\u000a on the concentration (10?6–10?3 M) and pH (2–11) of aqueous aluminum chloride, nitrate, and sulfate solutions. It is shown that, in the absence of aluminum\\u000a salts, the isoelectric point (IEP) of the particles is independent on the nature of acid anions and is

P. M. Mosur; Yu. M. Chernoberezhskii; A. V. Lorentsson

2008-01-01

38

Criticality experiments with mixed plutonium-uranium nitrate solution at plutonium fractions of 0. 2, 0. 5, and 1. 0 in annular cylindrical geometry  

SciTech Connect

The objective of these criticality experiments is to provide criticality data for Pu + U solutions for optimizing the physical size of equipment during fissile product conversion and storage and for the design of reprocessing plants. Prior to these measurements, little or no criticality data were available for mixed plutonium-uranium solutions in annular geometry. 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 facility of Pacific Northwest Laboratory. Criticality measurements were made with (Pu + U) nitrate solutions in a water-reflected annular vessel. The concentration of (Pu + U) in the nitrate solution was varied and ranged between 61 and 489 g (Pu + U)/l. The ratio of Pu to (Pu + U) in the solution also was varied, with measurements being made at {approx}0.52, {approx}0.23, {approx}0.97. The measurements provide data essential for validating criticality codes that may be used on configurations similar to those of the experiments.

Lloyd, R.C.; Koyama, T.

1988-01-01

39

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

40

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

41

Water Structure at the Air-Aqueous Interface of Divalent Cation and Nitrate Solutions Man Xu, Rick Spinney, and Heather C. Allen*  

E-print Network

Water Structure at the Air-Aqueous Interface of Divalent Cation and Nitrate Solutions Man Xu, Rick, Columbus, Ohio 43210 ReceiVed: July 24, 2008; ReVised Manuscript ReceiVed: December 4, 2008 The water surface structure of aqueous magnesium, calcium, and strontium nitrate solutions with six to seven water

42

Crystals Formed at 293 K by Aqueous Sulfate-Nitrate-Ammonium-Proton Aerosol Julie C. Schlenker, Adam Malinowski, Scot T. Martin,* Hui-Ming Hung, and Yinon Rudich  

E-print Network

Crystals Formed at 293 K by Aqueous Sulfate-Nitrate-Ammonium-Proton Aerosol Particles Julie C particles are commonly internal mixtures of sulfate, nitrate, ammonium, other inorganic and organic ions, nondissociated organic molecules, and insoluble inclusions, such as soot or mineral dust.7 Sulfate, nitrate

43

Nitrate Anions and Ion Pairing at the Air-Aqueous Interface Man Xu, Cheng Y. Tang, Aaron M. Jubb, Xiangke Chen, and Heather C. Allen*  

E-print Network

Nitrate Anions and Ion Pairing at the Air-Aqueous Interface Man Xu, Cheng Y. Tang, Aaron M. Jubb, Columbus, Ohio 43210 ReceiVed: June 18, 2008; ReVised Manuscript ReceiVed: October 31, 2008 Nitrate ions in a variety of atmospheric reactions. Thus, a fundamental understanding of nitrate ions at the air

44

Plutonium, uranium, nitrate measurements in PUREX process stream by remote fiber optic diode array spectrophotometry  

SciTech Connect

There is increasing interest in the development of real-time or near real-time spectrophotometric measurement of Pu(III), Pu(IV), Pu(VI), uranium, and nitrate in nitric acid in a process stream. A broad foundation for this measurement technique has been built at Savannah River Laboratory for the Savannah River Plant. A project is underway at Pacific Northwest Laboratory to develop the technology for PUREX plant process chemistry. The first application is the Plutionium Stripper Feed, where Pu(IV) concentrations of 10 to 50 g/L are expected, with Pu(III) and Pu(VI) being up to one tenth of that level. Nitrate concentrations of 1 to 3 /und/M are expected. This is the major difference between this application at PUREX and the work progressing at SRL, in which Pu concentrations are considerably less and nitrate levels of are considerably higher. This paper discusses the progress of our work, explains the hardware involved, discusses the use of the chemometric regression method, Partial Least Squares, and discusses the results obtained to date.

Baldwin, D.L.; Stromatt, R.W.

1988-03-01

45

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

Microsoft Academic Search

For water bodies where the nitrate concentrations exceed threshold values environmental agencies can propose measures to either reduce discharges and emissions of nitrate or to remediate nitrate polluted water bodies. Isotope data can support the identification of nitrate pollution sources and natural attenuation processes of nitrate. A review of surface water field studies evaluated the use of isotope data (e.g.

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

2010-01-01

46

Extraction of rare-earth metal(III) nitrates by neutral organophosphorus compounds from concentrated aqueous salt solutions  

Microsoft Academic Search

Equations describing isotherms of extraction of rare-earth metal(III) nitrates by neutral organo-phosphorus compounds over a wide range of component concentrations in aqueous and organic phases have been proposed. Constants of phase extraction and empirical parameters characterizing the influence of organic phase composition on the activity coefficients of the components have been presented.

A. K. Pyartman; E. A. Puzikov

1995-01-01

47

Criticality data and validation studies of plutonium-uranium nitrate solutions in annular geometry  

SciTech Connect

Critical experiments were performed at the Pacific Northwest Laboratory-Critical Mass Laboratory from 1985 to 1987 with mixed Pu + U nitrate solutions in annular geometry. The 25.4-cm-diam central region of the annual vessel contained various inserts, such as a bottle containing fissile solution and borated-concrete and cadmium-covered polyethylene annular inserts. The fissile solution concentrations ranged from 47 to 226 g Pu/[ell] with Pu/Pu + U ratios of 1.0, 0.5, and 0.2. The criticality data were used to validate two versions of the SCALE computer code system (SCALE-4 and SCALE-2). The analyses were performed with the 27-energy-group cross-section library, derived from the Evaluated Nuclear Data File B-Version IV. Computer models were prepared to accurately simulate all significant materials that would affect the system reactivity. The average calculated k[sub eff] for the 18 experiments was 1.008 ([sigma] = 0.006) with SCALE-4 and 1.004 ([sigma] = 0.006) with SCALE-2. Overall, the range of calculated k[sub eff]'s varied from 0.990 to 1.017. The results of the validation calculations indicate that the SCALE computer code system is capable of accurately modeling Pu + U nitrate solutions in annular geometry.

Smolen, G.R. (Oak Ridge National Lab., TN (United States). Computing and Telecommunications Div.); Lloyd, R.C. (Pacific Northwest Lab., Richland, WA (United States)); Koyama, Tomozo (Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan))

1994-09-01

48

The structure of plutonium(IV) oxide as hydrolysed clusters in aqueous suspensions.  

PubMed

The behavior of plutonium still puzzles scientists 70 years after its discovery. There are several factors making the chemistry of plutonium interesting including its ability to keep several oxidation states. Another unique property is that the oxidation states +III, +IV, +V and +VI may exist simultaneously in solution. Another property plutonium shares with some other tetravalent metal ions is the ability to form stable polynuclear complexes or colloids. The structures of freshly prepared and five-year old plutonium(IV) colloids are compared with crystalline plutonium(IV) oxide using Pu L(3)-edge EXAFS. It was shown that as the plutonium colloids age they do in fact shrink in size, contrary to previous expectations. The aged colloidal particles are indeed very small with only 3-4 plutonium atoms, and with a structure very similar to solid plutonium(IV) oxide, but with somewhat shorter mean Pu-O bond and Pu···Pu distances indicating a partial oxidation. The very small size of the colloidal particles is further supported by the fact that they do not sediment on heavy ultra-centrifugation. PMID:23175453

Ekberg, Christian; Larsson, Kristian; Skarnemark, Gunnar; Ödegaard-Jensen, Arvid; Persson, Ingmar

2013-02-14

49

Hydroxyl radical, sulfate radical and nitrate radical reactivity towards crown ethers in aqueous solutions  

NASA Astrophysics Data System (ADS)

Reaction rate constants of crown ethers (12-crown-4, 15-crown-5, 18-crown-6) and their analogs 1,4-dioxane (6C2) with some important oxidative radicals, hydroxyl radical (rad OH), sulfate radical (SO4rad -) and nitrate radical (NO3rad ), were determined in various aqueous solutions by pulse radiolysis and laser photolysis techniques. The reaction rate constants for 6C2 and crown ethers with rad OH and SO4rad - increase with the number of hydrogen atoms in the ethers, indicating that the hydrogen-atom abstraction is a dominant reaction between crown ethers and these two radicals. The presence of cations in solution has negligible effect on the rate constants of crown ether towards rad OH and SO4rad -. However, for the NO3rad , the rate constants are not proportional to the number of hydrogen atoms in ethers, and 12-crown-4 (12C4) is the most reactive compared with other crown ethers. Except 12C4 and 6C2, the cations in the aqueous solution affect the reactivities of 15-crown-5 (15C5) and 18-crown-6 (18C6). The cations with high binding stability for crown ether would improve the reactivity of 15C5. For the studied crown ethers, the reaction rate constants of these oxidative radicals have the order rad OH>SO4rad ->NO3rad . Furthermore, the formation of radicals after the reaction of crown ethers with sulfate radical could be observed in the range of 260-280 nm using laser photolysis and pulse radiolysis. This is the first report on the kinetic behavior of crown ethers with NO3rad , and it would be helpful for the understanding of stability of crown ethers in the processing of spent nuclear fuel.

Wan, L. K.; Peng, J.; Lin, M. Z.; Muroya, Y.; Katsumura, Y.; Fu, H. Y.

2012-05-01

50

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

51

Release of nitrous Acid and nitrogen dioxide from nitrate photolysis in acidic aqueous solutions.  

PubMed

Nitrate (NO3¯) is an abundant component of aerosols, boundary layer surface films, and surface water. Photolysis of NO3¯ leads to NO2 and HONO, both of which play important roles in tropospheric ozone and OH production. Field and laboratory studies suggest that NO3¯ photochemistry is a more important source of HONO than once thought, although a mechanistic understanding of the variables controlling this process is lacking. We present results of cavity-enhanced absorption spectroscopy measurements of NO2 and HONO emitted during photodegradation of aqueous NO3¯ under acidic conditions. Nitrous acid is formed in higher quantities at pH 2-4 than expected based on consideration of primary photochemical channels alone. Both experimental and modeled results indicate that the additional HONO is not due to enhanced NO3¯ absorption cross sections or effective quantum yields, but rather to secondary reactions of NO2 in solution. We find that NO2 is more efficiently hydrolyzed in solution when it is generated in situ during NO3¯ photolysis than for the heterogeneous system where mass transfer of gaseous NO2 into bulk solution is prohibitively slow. The presence of nonchromophoric OH scavengers that are naturally present in the environment increases HONO production 4-fold, and therefore play an important role in enhancing daytime HONO formation from NO3¯ photochemistry. PMID:25271384

Scharko, Nicole K; Berke, Andrew E; Raff, Jonathan D

2014-10-21

52

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

53

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

54

Criticality experiments with dilute plutonium-uranium nitrate solution at plutonium fractions of 0. 2 and 0. 5 in cylindrical geometry  

SciTech Connect

The objective of these experiments is to obtain data on the minimum fissil concentration for criticality from measurements on a large (low neutron leakage) cylindrical vessel. The limiting concentration is fundamental data unique to the particular fuel mixture studied and is important for criticality control. Prior to these measurements, no data existed concerning the effect of dissolved uranium on the minimum critical concentration of plutonium. These data can be applied whenever mixtures of plutonium and uranium exist, in the head end of a fuel reprocessing plant through the first solvent extraction cycle, in storage vessels, and during product conversion when a coprocessing scheme is used. A series of critical experiments was completed in large cylindrical geometry with mixed plutonium-uranium solutions with a water reflector. The concentrations were 22 and 53 g (Pu + U)/l with a plutonium-to-total-heavy-metal (HM) ratio (plutonium plus uranium) of 0.52 or 0.23, respectively. These experiments were a part of the Criticality Data Development Program between the US Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan.

Lloyd, R.C.; Matsumoto, T.

1987-01-01

55

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

56

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

2010-11-15

57

An Electronic Tongue Designed to Detect Ammonium Nitrate in Aqueous Solutions  

PubMed Central

An electronic tongue has been developed to monitor the presence of ammonium nitrate in water. It is based on pulse voltammetry and consists of an array of eight working electrodes (Au; Pt; Rh; Ir; Cu; Co; Ag and Ni) encapsulated in a stainless steel cylinder. In a first step the electrochemical response of the different electrodes was studied in the presence of ammonium nitrate in water in order to further design the wave form used in the voltammetric tongue. The response of the electronic tongue was then tested in the presence of a set of 15 common inorganic salts; i.e.; NH4NO3; MgSO4; NH4Cl; NaCl; Na2CO3; (NH4)2SO4; MgCl2; Na3PO4; K2SO4; K2CO3; CaCl2; NaH2PO4; KCl; NaNO3; K2HPO4. A PCA plot showed a fairly good discrimination between ammonium nitrate and the remaining salts studied. In addition Fuzzy Art map analyses determined that the best classification was obtained using the Pt; Co; Cu and Ni electrodes. Moreover; PLS regression allowed the creation of a model to correlate the voltammetric response of the electrodes with concentrations of ammonium nitrate in the presence of potential interferents such as ammonium chloride and sodium nitrate. PMID:24145916

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

2013-01-01

58

Micellar properties of tetradecyltrimethylammonium nitrate in aqueous solutions at various temperatures and in water-benzyl alcohol mixtures at 25 °C  

Microsoft Academic Search

The micellar properties of tetradecyltrimethylammonium nitrate (C14TANO 3) in aqueous solutions in the temperature range of 10 to 35 °C and in aqueous solutions of benzyl alcohol (BzOH) at 25 °C were studied conductometrically. The specific conductivity data served for the evaluation of critical micelle concentration, cmc, and the degree of ionization of the micelles, ?, of the surfactant. From the temperature

A González-Pérez; J. Czapkiewicz; J. L. Del Castillo; J. R. Rodríguez

2004-01-01

59

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

SciTech Connect

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

Nielsen, Christopher E. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Wang, Xihai [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Robinson, Robert J. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Brooks, Antone L. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Lovaglio, Jamie A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Patton, Kristin M. [Battelle Toxicology Northwest, Richland, WA (United States); McComish, Stacey [United States Transuranium and Uranium Registries, Washington State University, College of Pharmacy, Richland, WA (United States); Tolmachev, Sergei Y. [United States Transuranium and Uranium Registries, Washington State University, College of Pharmacy, Richland, WA (United States); Morgan, William F. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

2014-01-01

60

NMR AND IR SPECTROMETRY STUDIES OF MONOAMIDE COMPLEXES WITH PLUTONIUM(IV) AND LANTHANIDE(III) NITRATES  

Microsoft Academic Search

Monoamide (E) extractants are potential candidates to replace the tri-n-butyl phosphate (TBP) used in the reprocessing of nuclear fuels. In the present study, we essentially used NMR (13C and 1H) spectroscopy to identify the kinds of structural parameters conditioning the selectivity and efficiency of monoamide extractants. Information on nitrate groups bonded to the metallic ions and to the carbonyl moiety

C. Berthon; C. Chachaty

1995-01-01

61

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

62

A spectrophotometric study of Am(iii) complexation with nitrate in aqueous solution at elevated temperatures.  

PubMed

The complexation of americium(iii) with nitrate was studied at temperatures from 10 to 85 °C in 1 M HNO3-HClO4 by spectrophotometry. The 1?:?1 complex species, AmNO3(2+), was identified and the stability constants were calculated from the absorption spectra recorded for titrations at several temperatures. Specific ion interaction theory (SIT) was used for ionic strength corrections to obtain the stability constants of AmNO3(2+) at infinite dilution and variable temperatures. The absorption spectra of Am(iii) in diluted HClO4 were also reviewed, and the molar absorptivity of Am(iii) at around 503 nm and 813 nm was re-calibrated by titrations with standardized DTPA solutions to determine the concentration of Am(iii). PMID:24999760

Tian, Guoxin; Shuh, David K

2014-09-16

63

Aggregation and sedimentation stability of microcrystalline cellulose suspensions in aqueous aluminum nitrate solutions  

Microsoft Academic Search

The aggregation and sedimentation stability of dilute suspensions of microcrystalline cellulose in aqueous solutions of Al(NO3)3(2 × 10?5–2 × 10?3 mol\\/l) is studied by the photometric method at pH 2–11. It is found that, in the absence of Al(NO3)3, microcrystalline cellulose suspensions are stable with respect to aggregation throughout the pH range in question. The addition\\u000a of Al(NO3)3 induces the

P. M. Mosur; A. V. Lorentsson; Yu. M. Chernoberezhskii

2009-01-01

64

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

Microsoft Academic Search

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

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

2008-01-01

65

Size effect of hematite and corundum inclusions on the efflorescence relative humidities of aqueous ammonium nitrate particles  

E-print Network

ammonium nitrate particles Jeong-Ho Han Department of Environmental Chemistry, Atmospheric Science Division for a mechanism of heterogeneous nucleation that proceeds by chemisorption of nitrate at the surface of the oxide, ammonium nitrate, mineral dusts, coated particles, heterogeneous nucleation 1. Introduction [2

66

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

SciTech Connect

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

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

1987-07-01

67

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

68

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

PubMed

Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to investigate the species and structures existing in a series of ZnCl(2)-H(2)O-NaCl solutions with different chloride/zinc ratios and in a solution of ZnCl(2) 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 Zn(2+) is significantly related to the chloride/zinc ratio, and no inner complex formation between Zn(2+) and Cl(-) ions has been detected for low ZnCl(2) concentration (0.1 and 0.2 M). Conversely, in the same concentration range (0.13 M) the ZnCl(2) species do not dissociate in EAN and the Zn(2+) 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. PMID:22029326

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

2011-10-21

69

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

70

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

71

Purification of alkali metal nitrates  

DOEpatents

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

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

1985-05-14

72

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

PubMed

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

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

2014-08-15

73

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

74

Plutonium controversy  

SciTech Connect

The toxicity of plutonium is discussed, particularly in relation to controversies surrounding the setting of radiation protection standards. The sources, amounts of, and exposure pathways of plutonium are given and the public risk estimated. (ACR)

Richmond, C.R.

1980-01-01

75

Plutonium pyrophoricity  

Microsoft Academic Search

A review of the published literature on ignition and burning of plutonium metal was conducted in order to better define the characteristic of pyrophoric plutonium. The major parameter affecting ignition is the surface area\\/mass ratio of the sample. Based on this parameter, plutonium metal can be classified into four categories: (1) bulk metal, (2) film and foils, (3) chips and

Stakebake

1992-01-01

76

Nitrate formation in atmospheric aerosols  

Microsoft Academic Search

Equilibrium nitrate levels in aqueous solution in the presence of sodium chloride, nitric oxide, nitrogen dioxide, sulfur dioxide, carbon dioxide, ammonia, and sulfuric acid are calculated. Nitrate levels in solution are of the order of those observed in the atmosphere when the gaseous concentrations are at typical urban levels. Sulfate levels in such solutions are predicted to be relatively low

Ann E. Orel; John H. Seinfeld

1977-01-01

77

Thermochemical nitrate reduction  

SciTech Connect

A series of preliminary experiments was conducted directed at thermochemically converting nitrate to nitrogen and water. Nitrates are a major constituent of the waste stored in the underground tanks on the Hanford Site, and the characteristics and effects of nitrate compounds on stabilization techniques must be considered before permanent disposal operations begin. For the thermochemical reduction experiments, six reducing agents (ammonia, formate, urea, glucose, methane, and hydrogen) were mixed separately with {approximately}3 wt% NO{sub 3}{sup {minus}} solutions in a buffered aqueous solution at high pH (13); ammonia and formate were also mixed at low pH (4). Reactions were conducted in an aqueous solution in a batch reactor at temperatures of 200{degrees}C to 350{degrees}C and pressures of 600 to 2800 psig. Both gas and liquid samples were analyzed. The specific components analyzed were nitrate, nitrite, nitrous oxide, nitrogen, and ammonia. Results of experimental runs showed the following order of nitrate reduction of the six reducing agents in basic solution: formate > glucose > urea > hydrogen > ammonia {approx} methane. Airnmonia was more effective under acidic conditions than basic conditions. Formate was also effective under acidic conditions. A more thorough, fundamental study appears warranted to provide additional data on the mechanism of nitrate reduction. Furthermore, an expanded data base and engineering feasibility study could be used to evaluate conversion conditions for promising reducing agents in more detail and identify new reducing agents with improved performance characteristics.

Cox, J.L.; Lilga, M.A.; Hallen, R.T.

1992-09-01

78

Nitrate Protocol  

NSDL National Science Digital Library

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

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

2003-08-01

79

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

80

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

Microsoft Academic Search

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

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

2008-01-01

81

Effects of dissolved oxygen on formation of corrosion products and concomitant oxygen and nitrate reduction in zero-valent iron systems with or without aqueous Fe 2+  

Microsoft Academic Search

Batch tests were conducted in zero-valent iron (ZVI or Fe0) systems to investigate oxygen consumption and the effect of dissolved oxygen (DO) on formation of iron corrosion products, nitrate reduction, the reactivity of Fe0, the role Fe2+ (aq) played, and the fate of Fe2+. The study indicates that without augmenting Fe2+ (aq), neither nitrate nor DO could be removed efficiently

Yong H. Huang; Tian C. Zhang

2005-01-01

82

Nitrate reduction  

DOEpatents

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

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

2000-01-01

83

Plutonium aging  

SciTech Connect

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

Olivas, J.D.

1999-03-01

84

Extraction and Purification of Plutonium by a Tertiary Amine; EXTRACTION ET PURIFICATION DU PLUTONIUM PAR UNE AMINE TERTIAIRE  

Microsoft Academic Search

Trilaurylamins diluted with a paraffinic solvent (dodecane) was studied ; as part of the research dealing with the separation and purification of plutonium. ; The physical properties (solubility of nitrates in the amine as a function of ; temperature) and the resistance to radiation of this substance were examined. ; The extraction characteristics of nitric solutions of plutonium, uranium, and

M. de Trentinian; A. Chesne

1960-01-01

85

Plutonium pyrophoricity  

SciTech Connect

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

Stakebake, J.L.

1992-06-02

86

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

Microsoft Academic Search

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.

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

2011-01-01

87

Energy Transfer between Ln(III) Ions in Aqueous Solutions Upon Formation of Labile Binuclear Fluoride and Nitrate Complexes of These Ions  

Microsoft Academic Search

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

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

2000-01-01

88

Evaluation of nitrate destruction methods  

SciTech Connect

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

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

1993-03-30

89

Recovery of plutonium from plutonium-beryllium neutron sources.  

National Technical Information Service (NTIS)

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

M. J. Palmer

1990-01-01

90

Oxidation of Nitric Oxide in Aqueous Solution to Nitrite but not Nitrate: Comparison with Enzymatically Formed Nitric Oxide From L-Arginine  

NASA Astrophysics Data System (ADS)

Nitric oxide (NO) in oxygen-containing aqueous solution has a short half-life that is often attributed to a rapid oxidation to both NO^-_2 and NO^-_3. The chemical fate of NO in aqueous solution is often assumed to be the same as that in air, where NO is oxidized to NO_2 followed by dimerization to N_2O_4. Water then reacts with N_2O_4 to form both NO^-_2 and NO^-_3. We report here that NO in aqueous solution containing oxygen is oxidized primarily to NO^-_2 with little or no formation of NO^-_3. In the presence of oxyhemoglobin or oxymyoglobin, however, NO and NO^-_2 were oxidized completely to NO^-_3. Methemoglobin was inactive in this regard. The unpurified cytosolic fraction from rat cerebellum, which contains constitutive NO synthase activity, catalyzed the conversion of L-arginine primarily to NO^-_3 (NO^-_2/NO^-_3 ratio = 0.25). After chromatography on DEAE-Sephacel or affinity chromatography using 2',5'-ADP-Sepharose 4B, active fractions containing NO synthase activity catalyzed the conversion of L-arginine primarily to NO^-_2 (NO^-_2/NO^-_3 ratio = 5.6) or only to NO^-_2, respectively. Unpurified cytosol from activated rat alveolar macrophages catalyzed the conversion of L-arginine to NO^-_2 without formation of NO^-_3. Addition of 30 ?M oxyhemoglobin to all enzyme reaction mixtures resulted in the formation primarily of NO^-_3 (NO^-_2/NO^-_3 ratio = 0.09 to 0.20). Cyanide ion, which displaces NO^-_2 from its binding sites on oxyhemoglobin, inhibited the formation of NO^-_3, thereby allowing NO^-_2 to accumulate. These observations indicate clearly that the primary decomposition product of NO in aerobic aqueous solution is NO^-_2 and that further oxidation to NO^-_3 requires the presence of additional oxidizing species such as oxyhemoproteins.

Ignarro, Louis J.; Fukuto, Jon M.; Griscavage, Jeannete M.; Rogers, Norma E.; Byrns, Russell E.

1993-09-01

91

Toward a general parameterization of N 2 O 5 reactivity on aqueous particles: the competing effects of particle liquid water, nitrate and chloride  

Microsoft Academic Search

The heterogeneous reaction of N2O5 on mixed organic-inorganic aerosol particles was investigated using an entrained aerosol flow tube coupled to a custom-built chem- ical ionization mass spectrometer. Laboratory results on aqueous particles confirm a strong dependence of the reac- tive uptake coefficient ( ) on particle liquid water, for par- ticle water concentrations below 15 M, and the molar ra-

T. H. Bertram; J. A. Thornton

2009-01-01

92

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

Microsoft Academic Search

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

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

2000-01-01

93

Electrolytic production of uranous nitrate  

SciTech Connect

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

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

1980-04-01

94

Processing of Non-PFP Plutonium Oxide in Hanford Plants  

SciTech Connect

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

Jones, Susan A.; Delegard, Calvin H.

2011-03-10

95

A new isolation procedure of nitrate from freshwater for nitrogen and oxygen isotope analysis  

E-print Network

A new isolation procedure of nitrate from freshwater for nitrogen and oxygen isotope analysis) analysis of nitrate (NO3 ­ ) from aqueous samples can be used to determine nitrate sources and to study N an accurate, fast and inexpensive analysis. Here, we present a new simple method for the isolation of nitrate

Gilli, Adrian

96

Method for aqueous radioactive waste treatment  

DOEpatents

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

Bray, Lane A. (Richland, WA); Burger, Leland L. (Richland, WA)

1994-01-01

97

Energy Transfer between Ln(III) Ions in Aqueous Solutions Upon Formation of Labile Binuclear Fluoride and Nitrate Complexes of These Ions  

NASA Astrophysics Data System (ADS)

The influence of anions on nonradiative electronic energy transfer between lanthanide ions in aqueous solutions is studied. The rate constant k t of energy transfer was found to increase by three orders of magnitude upon addition of salts of hydrofluoric acid to the solution. This effect is caused by the formation of bridge labile binuclear complexes, an excited energy donor-fluorine anion-acceptor, which increase the encounter time between a donor and an acceptor, resulting in the increase in the probability of energy transfer. The independence of k t of the Förster overlap integral in the bridge complex containing F- was explained by the fact that energy transfer occurs in each event of the binuclear complex formation, the maximum rate constant of energy transfer being equal to the rate constant of the binuclear complex association. Bridge complexes formed via the NO{3/-} anion are also considered. These binuclear complexes are unstable, and k t for them is proportional to the Förster overlap integral. In this case, energy transfer occurs not during each event of the complex formation. This allows us to estimate the lower limit of the dissociation constant of the binuclear complex and its stability constant. Thus, the study of influence of various anions on energy transfer represents a new efficient luminescent method for analysis of properties of labile binuclear complexes in solutions.

Sveshnikova, E. B.; Dudar', S. S.; Ermolaev, V. L.

2000-06-01

98

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

99

Method for dissolving delta-phase plutonium  

SciTech Connect

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

1992-12-31

100

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

101

PLUTONIUM-239 AND AMERICIUM-241 UPTAKE BY PLANTS FROM SOIL  

EPA Science Inventory

Alfalfa was grown in soil contaminated with plutonium-239 dioxide (239PuO2) at a concentration of 29.7 nanocuries per gram (nCi/g). In addition to alfalfa, radishes, wheat, rye, and tomatoes were grown in soils contaminated with americium-241 nitrate (241Am(NO3)3) at a concentrat...

102

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

103

Recovery of plutonium from plutonium-beryllium neutron sources  

Microsoft Academic Search

At the Los Alamos National Laboratory, plutonium-beryllium neutron sources have traditionally been processed for plutonium recovery by precipitating the plutonium as plutonium oxalate, calcining to plutonium dioxide, redissolving the oxide and then precipitating as oxalate again. In most cases three dissolutions of the oxide are required to reduce beryllium content enough to meet specifications. We first introduced an ion-exchange process

1990-01-01

104

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

105

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

106

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

107

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

108

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 Section 181.33 Food and Drugs...Prior-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and...

2013-04-01

109

21 CFR 181.33 - Sodium nitrate and potassium nitrate.  

...2014-04-01 2014-04-01 false Sodium nitrate and potassium nitrate. 181.33 Section 181.33 Food and Drugs...Prior-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and...

2014-04-01

110

21 CFR 181.33 - Sodium nitrate and potassium nitrate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Sodium nitrate and potassium nitrate. 181.33 Section 181.33 Food and Drugs...Prior-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and...

2012-04-01

111

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

Microsoft Academic Search

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

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

2004-01-01

112

Determination of plutonium-239 + plutonium-240 and plutonium-241 in environmental samples using low-level liquid scintillation spectrometry.  

PubMed

A radiochemical method for the simultaneous determination of 239Pu + 240Pu and 241Pu in environmental samples has been developed. In the course of the analysis a 236Pu tracer was used for estimating the chemical yield of plutonium isotopes. After suitable pre-treatment of the sample, the plutonium nuclides in solution were coprecipitated with iron(III) hydroxide and calcium oxalate and isolated further from impurities and interfering radionuclides by means of anion-exchange chromatography. Plutonium isotopes in the eluate (NH4I-HCI) were converted into nitrate form and then extracted with 20 ml of 5% bis(2-ethylhexyl) hydrogen phosphate extractive cocktail. The final organic solution was measured spectrometrically using an ultra-low-level liquid scintillation spectrometer, Quantulus (LKB, 1220 Wallac). The chemical yields of plutonium range from 25 to 50% for 100 I of sea-water and 30 to 60% for 40 g of dried soil sample. The counting efficiencies are nearly 100% for 239Pu + 240Pu and 48.8% for 241Pu, respectively. The detection limits were estimated to be 0.20 mBq for 239Pu + 240Pu and 2.2 mBq for 241Pu, respectively. The proposed procedure has been tested for the simultaneous determination of 239Pu + 240Pu and 241Pu in sea-water (Irish Sea, North Sea) and soils (Cumbrian coast, UK; Byelorussia, USSR). PMID:1580376

Yu, Y F; Bjørnstad, H E; Salbu, B

1992-03-01

113

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

SciTech Connect

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

ULLAH, M K

2001-02-26

114

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

115

Alkali metal nitrate purification  

DOEpatents

A process is disclosed for removing contaminants from impure alkali metal nitrates containing them. The process comprises heating the impure alkali metal nitrates in solution form or molten form at a temperature and for a time sufficient to effect precipitation of solid impurities and separating the solid impurities from the resulting purified alkali metal nitrates. The resulting purified alkali metal nitrates in solution form may be heated to evaporate water therefrom to produce purified molten alkali metal nitrates suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of purified alkali metal nitrates.

Fiorucci, Louis C. (Hamden, CT); Morgan, Michael J. (Guilford, CT)

1986-02-04

116

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

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

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

117

Plutonium storage phenomenology  

SciTech Connect

Plutonium has been produced, handled, and stored at Department of Energy (DOE) facilities since the 1940s. Many changes have occurred during the last 40 years in the sources, production demands, and end uses of plutonium. These have resulted in corresponding changes in the isotopic composition as well as the chemical and physical forms of the processed and stored plutonium. Thousands of ordinary food pack tin cans have been used successfully for many years to handle and store plutonium. Other containers have been used with equal success. This paper addressees the exceptions to this satisfactory experience. To aid in understanding the challenges of handling plutonium for storage or immobilization the lessons learned from past storage experience and the necessary countermeasures to improve storage performance are discussed.

Szempruch, R.

1995-12-01

118

Nitrate and Nitrite Reduction by Wolffia arrhiza.  

PubMed

Nitrate reductase was not found to be present in or associated with partially purified, intact chloroplasts aqueously isolated from Wolffia arrhiza. Such chloroplasts are capable of using nitrite but not nitrate as an electron acceptor during light-stimulated electron transport in the absence of additional cytoplasmic components. When nitrite acts as an electron acceptor under these conditions, on the average 1.5 moles of oxygen are evolved per mole of nitrite reduced by the chloroplasts, indicating a probable reduction of nitrite to ammonia. Chloroplasts ruptured by osmotic shock fail to reduce nitrite in the absence of additional components. PMID:16657592

Swader, J A; Stocking, C R

1971-02-01

119

Plutonium radiation surrogate  

DOEpatents

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

Frank, Michael I. (Dublin, CA)

2010-02-02

120

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

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

121

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

122

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

123

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

124

Plutonium: The disposal decision  

Microsoft Academic Search

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

1997-01-01

125

NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN  

SciTech Connect

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

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

2012-05-29

126

Cylodextrin Polymer Nitrate  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

127

Plutonium Disposition Now!  

SciTech Connect

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

Buckner, M.R.

1995-05-24

128

Nitrate content and nitrate reductase activity in Rumex obtusifolius L  

Microsoft Academic Search

The aim of this work was to investigate the effect of nitrogen starvation and subsequent fentilization with nitrate or ammonium on nitrate content and nitrate reductase activity of Rumex obtusifolius L. under natural conditions.

A. Melzer; G. Gebauer; H. Rehder

1984-01-01

129

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

130

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

131

Reduction of uranium (VI) to uranium (IV) by hydrazine in an aqueous nitric acid-30% tri-n-butyl phosphate (TBP) volume emulsion  

SciTech Connect

Tetravalent uranium which has been stabilized with hydrazine is widely used in the extraction technology of regenerating irradiated nuclear fuel as an agent for reduction of plutonium (IV) to plutonium (III). However, it is well known that in two-phase extraction systems of the type aqueous nitric acid solutions of U(IV)-TBP solutions in inert diluents, the U(IV) is insufficiently stable and is oxidized to U(VI) as a result of reaction with nitrous acid which accumulates in the organic phase. The results of kinetic experiments at various concentration of nitric acid, uranyl nitrate, and hydrazine and at various temperatures show that the order of the reduction of U(VI) to U(IV) in the two-phase extraction system emulsion 30% TBP by volume solution in n-paraffins-aqueous nitric acid is zero with respect to uranium and is unity with respect to hydrazine. Typical kinetic curves for the U(VI)-time dependence are given. The kinetic dependences were analyzed in the time range for about 50% completion of reaction.

Solovkin, A.S.; Druzherukov, V.I.

1987-09-01

132

Drinking Water Problems: Nitrates  

E-print Network

High levels of nitrates in drinking water can be harmful for very young infants and susceptible adults. This publication explains how people are exposed to nitrates, what health effects are caused by them in drinking water and how to remove them....

Dozier, Monty; Melton, Rebecca; Hare, Michael; Hopkins, Janie; Lesikar, Bruce J.

2008-03-28

133

THE EXTRACTION OF URANIUM AND PLUTONIUM FROM NITRIC ACID SOLUTIONS BY TERTIARY AMINES  

Microsoft Academic Search

In the extraction of Pu(IV) nitrate from uranium contairing aqueous ; solutions by means of long chain tertiary amines, the partition coefficient of ; Pu(IV) is influenced by the concentration of nitric acid, uranyl nitrate, and by ; the concentration of the amine in the diluent. At high urarium concentration ; extraction of Pu(IV) ceases to be dependent upon the

F. Baroncelli; G. Scibona; M. Zifferero

1963-01-01

134

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

135

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

136

Assessment of the risk of transporting plutonium dioxide and liquid plutonium nitrate by train  

Microsoft Academic Search

The risk analysis model is applied to the assessment of the risk of Pu releases due to transportation accidents and package misclosure and degradation. The transport system and accident environment are described and release sequences postulated. Results are related to the early 1980s, when Pu shipments are expected to be more frequent (18 metric tons Pu shipped by rail per

D. K. Davis; S. W. Heaberlin; J. F. Johnson; P. L. Peterson

1977-01-01

137

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

138

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

...Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2014-07-01

139

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

Code of Federal Regulations, 2013 CFR

...Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2013-07-01

140

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

Code of Federal Regulations, 2011 CFR

...Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2011-07-01

141

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

Code of Federal Regulations, 2012 CFR

...Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2012-07-01

142

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

Code of Federal Regulations, 2010 CFR

...Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2010-07-01

143

Aqueous divalent metalnitrate interactions: hydration versus ion James P. Larentzos,b  

E-print Network

con- ducted to investigate ion pairing in nitrate aqueous solutions, mainly focusing on individual metal­nitrate salts and the effects of concentration, temperature, and solvent.5,11,12,14­18 Few studies cation. We are interested in understanding ion pairing phenomena in aqueous media and at the air

144

Plutonium: An introduction  

SciTech Connect

This report is a summary of the history and properties of plutonium. It presents information on the atoms, comparing chemical and nuclear properties. It looks at the history of the atom, including its discovery and production methods. It summarizes the metallurgy and chemistry of the element. It also describes means of detecting and measuring the presence and quantity of the element.

Condit, R.H.

1993-10-01

145

Atomic spectrum of plutonium  

SciTech Connect

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

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

1984-08-01

146

Quantum Yield of Hydroxyl Radical from Photolysis of Nitrate on Ice  

NASA Astrophysics Data System (ADS)

The photodecomposition of nitrate generates hydroxyl radical (OH) and NOx, thereby altering the chemical composition of the snowpack as well as the overlying atmospheric boundary layer. Nitrate photolysis in aqueous solutions has been extensively studied and proceeds via two pathways:\\ NO3- + h\

Chu, L.; Anastasio, C.

2002-12-01

147

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

148

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

Microsoft Academic Search

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

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

2007-01-01

149

An improved, computer-based, on-line gamma monitor for plutonium anion exchange process control  

SciTech Connect

An improved, low-cost, computer-based system has replaced a previously developed on-line gamma monitor. Both instruments continuously profile uranium, plutonium, and americium in the nitrate anion exchange process used to recover and purify plutonium at the Los Alamos Plutonium Facility. The latest system incorporates a personal computer that provides full-feature multichannel analyzer (MCA) capabilities by means of a single-slot, plug-in integrated circuit board. In addition to controlling all MCA functions, the computer program continuously corrects for gain shift and performs all other data processing functions. This Plutonium Recovery Operations Gamma Ray Energy Spectrometer System (PROGRESS) provides on-line process operational data essential for efficient operation. By identifying abnormal conditions in real time, it allows operators to take corrective actions promptly. The decision-making capability of the computer will be of increasing value as we implement automated process-control functions in the future. 4 refs., 6 figs.

Pope, N.G.; Marsh, S.F.

1987-06-01

150

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

151

Luminescent determination of neptunium and plutonium in the environment  

Microsoft Academic Search

The possibilities of membrane preconcentration of neptunium and plutonium from acidic soil leach have been studied. The elaborated technique involves two steps: liquid extraction of Pu(IV) and Np(IV) by HDEHP from the soil leach and accumulation of these elements by solid supported aqueous membrane with K10P2W17O61 in inner solution. It has been shown that actinide's content in the membrane can

A. P. Novikov; M. N. Mikheeva; O. I. Gracheva; B. F. Myasoedov

1997-01-01

152

Conversion of Uranium Oxide into Nitrate with Nitrogen Dioxide  

Microsoft Academic Search

In order to decrease the amount of aqueous liquid waste discharged from nuclear fuel reprocessing, the conversion of uranium dioxide into its nitrate using liquefied nitrogen dioxide was studied. Uranium dioxide powder was immersed in liquefied nitrogen dioxide at 313 K after a pretreatment by the oxidation of the uranium dioxide with nitrogen dioxide and air at 523 K. Seventy-nine

Kayo Sawada; Daisuke Hirabayashi; Youichi Enokida; Ichiro Yamamoto

2008-01-01

153

Plutonium age dating reloaded  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

154

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

155

SOIL NITRATE TESTS FOR WISCONSIN  

E-print Network

SOIL NITRATE TESTS FOR WISCONSIN CROPPING SYSTEMS L.G. Bundy Dept. of Soil Science University of Wisconsin #12;Why Use Soil Nitrate Tests? · Agronomic and environmental benefits · Predict corn N needs ­ Improved accuracy ­ Site-and year-specific · Minimize nitrate loss #12;#12;Preplant Soil Nitrate Test (PPNT

Balser, Teri C.

156

Surprising Coordination for Plutonium in the First Plutonium (III) Borate  

SciTech Connect

The first plutonium(III) borate, Pu{sub 2}[B{sub 12}O{sub 18}(OH){sub 4}Br{sub 2}(H{sub 2}O){sub 3}]·0.5H{sub 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.

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

2011-01-01

157

Thermal decomposition hazard evaluation of hydroxylamine nitrate.  

PubMed

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

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

2006-03-17

158

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

159

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

160

Huge Seebeck coefficients in non-aqueous electrolytes  

E-print Network

The Seeebeck coefficients of the non-aqueous electrolytes tetrabutylammonium nitrate, tetraoctylphosphonium bromide and tetradodecylammonium nitrate in 1-octanol, 1-dodecanol and ethylene-glycol are measured in a temperature range from T=30 to T=45 C. The Seebeck coefficient is generally of the order of a few hundreds of microvolts per Kelvin for aqueous solution of inorganic ions. Here we report huge values of 7 mV/K at 0.1M concentration for tetrabutylammonium nitrate in 1-dodecanol. These striking results open the question of unexpectedly large kosmotrope or "structure making" effects of tetraalkylammonium ions on the structure of alcohols.

M. Bonetti; S. Nakamae; M. Roger; P. Guenoun

2011-02-11

161

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

162

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

163

Theoretical Study of Plutonium(IV) Complexes Formed within the PUREX Process: A Proposal of a Plutonium Surrogate in Fire Conditions.  

PubMed

We present a relativistic quantum chemical study to determine the best surrogate for plutonium(IV) to be used in experimental investigations of the behavior of plutonium-nitrate-TBP in fire conditions that might occur in the nuclear fuel refining process known as PUREX. In this study geometries and stabilities of Pu(NO3)6(2-) and Pu(NO3)4(TBP)2 complexes were compared to that of equivalent complexes of selected elements from the lanthanide and actinide series (Ce, Th, U) chosen on the basis of similar ionic radii and stability as tetravalent species. PBE and PBE0 DFT functionals have proven to be sufficient and affordable for qualitative studies, performing as good as the wave function based correlated method MP2. On the basis of our results, cerium(IV) appears to be a good surrogate for plutonium(IV). PMID:25290588

Sulka, Martin; Cantrel, Laurent; Vallet, Valérie

2014-10-30

164

Desferrioxamine Inhibits Protein Tyrosine Nitration: Mechanisms and Implications  

PubMed Central

Tissues are exposed to exogenous and endogenous nitrogen dioxide (•NO2), which is the terminal agent in protein tyrosine nitration. Besides iron chelation, the hydroxamic acid (HA) desferrioxamine (DFO) shows multiple functionalities including nitration inhibition. To investigate mechanisms whereby DFO affects 3-nitrotyrosine (3-NT) formation, we utilized gas phase •NO2 exposures, to limit introduction of other reactive species, and a lung surface model wherein red cell membranes (RCM) were immobilized under a defined aqueous film. When RCM were exposed to •NO2 covered by +/? DFO: (i) DFO inhibited 3-NT formation more effectively than other HA and non-HA chelators; (ii) 3-NT inhibition occurred at very low [DFO] for prolonged times; and (iii) 3-NT formation was iron independent but inhibition required DFO present. DFO poorly reacted with •NO2 compared to ascorbate, assessed via •NO2 reactive absorption and aqueous phase oxidation rates, yet limited 3-NT formation at far lower concentrations. DFO also inhibited nitration under aqueous bulk phase conditions, and inhibited 3-NT generated by active myeloperoxidase “bound” to RCM. Per the above and kinetic analyses suggesting preferential DFO versus •NO2 reaction within membranes, we conclude that DFO inhibits 3-NT formation predominantly by facile repair of the tyrosyl radical intermediate, which prevents •NO2 addition, and thus nitration, and potentially influences biochemical functionalities. PMID:22705369

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

2012-01-01

165

Nitrate uptake and nitrate reduction in synchronous Chlorella  

Microsoft Academic Search

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

Rudolf Tischner; Harald Lorenzen

1979-01-01

166

Radiation chemistry of aqueous solutions of actinides  

Microsoft Academic Search

The data on radiolytic transformations of ions of uranium, neptunium, plutonium, americium, curium and transcurium elements in aqueous solutions are generalised. The results of studies on the kinetics of fast reactions of these ions with primary products of water radiolysis (hydrated electron e-aq, H, OH, and O- radicals and H2O2), many inorganic (Cl2-, NO3, SO4-, CO3-, O3- etc.) and organic

Alexei K. Pikaev; Vladimir P. Shilov; Andrei V. Gogolev

1997-01-01

167

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

168

Nitrate and Nitrite Reduction by Wolffia arrhiza1  

PubMed Central

Nitrate reductase was not found to be present in or associated with partially purified, intact chloroplasts aqueously isolated from Wolffia arrhiza. Such chloroplasts are capable of using nitrite but not nitrate as an electron acceptor during light-stimulated electron transport in the absence of additional cytoplasmic components. When nitrite acts as an electron acceptor under these conditions, on the average 1.5 moles of oxygen are evolved per mole of nitrite reduced by the chloroplasts, indicating a probable reduction of nitrite to ammonia. Chloroplasts ruptured by osmotic shock fail to reduce nitrite in the absence of additional components. PMID:16657592

Swader, J. A.; Stocking, C. R.

1971-01-01

169

Electrochemical reduction of nitrate in the presence of an amide  

DOEpatents

The electrochemical reduction of nitrates in aqueous solutions thereof in the presence of amides to gaseous nitrogen (N.sub.2) is described. Generally, electrochemical reduction of NO.sub.3 proceeds stepwise, from NO.sub.3 to N.sub.2, and subsequently in several consecutive steps to ammonia (NH.sub.3) as a final product. Addition of at least one amide to the solution being electrolyzed suppresses ammonia generation, since suitable amides react with NO.sub.2 to generate N.sub.2. This permits nitrate reduction to gaseous nitrogen to proceed by electrolysis. Suitable amides include urea, sulfamic acid, formamide, and acetamide.

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

2002-01-01

170

Conversion of Uranium Oxide into Nitrate with Nitrogen Dioxide  

NASA Astrophysics Data System (ADS)

In order to decrease the amount of aqueous liquid waste discharged from nuclear fuel reprocessing, the conversion of uranium dioxide into its nitrate using liquefied nitrogen dioxide was studied. Uranium dioxide powder was immersed in liquefied nitrogen dioxide at 313 K after a pretreatment by the oxidation of the uranium dioxide with nitrogen dioxide and air at 523 K. Seventy-nine % of the uranium dioxide, whose initial feed amount was 0.3 g, was converted into a water soluble compound. Based on an XRD analysis of the compound, uranyl nitrate trihydrate (UO2(NO3)2·3H2O) was confirmed.

Sawada, Kayo; Hirabayashi, Daisuke; Enokida, Youichi; Yamamoto, Ichiro

171

From separations to reconstitution - a short history of Plutonium in the U.S. and Russia  

SciTech Connect

During the cold war plutonium was produced in reactors in both the US and Russia. It was then separated from the residual uranium and fission products by a variety of precipitation processes, such as Bismuth Phosphate, Redox, Butex, Purex, etc. in the US and uranium acetate and Purex in Russia. After a period of time in the field, plutonium weapons were recycled and the plutonium re-purified and returned to weapons. purification was accomplished by a variety of aqueous and molten salt processes, such as nitric-hydrofluoric acid dissolution followed by anion exchange, Purex modifications, molten salt extraction, electrorefining, etc. in the US and nitric acid dissolution or sodium hydroxide fusion followed by anion exchange in Russia. At the end of the Cold War, plutonium production of weapons-grade plutonium was cut off in the US and is expected to be cut off in Russia shortly after the turn of the century. Now both countries are looking at methods to reconstitute plutonium with fission products to render it no longer useful for nuclear weapons. These methods include immobilization in a ceramic matrix and then encasement in fission product laden glass, irradiation of MOX fuel, and disposal as waste in WIPP in the US and irradiation of MOX fuel in Russia. This paper details the contrast between the treatment of plutonium during the cold war and after the cold war was over.

Gray, L W

1999-04-15

172

EXAFS studies of structural changes in fragile glasses of zinc nitrate and nickel nitrate hydrates.  

PubMed

The ionic structures of aqueous solutions of two sets of transition metal nitrates have been studied in the liquid and glass states by EXAFS spectroscopy. Experiments were carried out on Zn(NO3)2.xH2O, with x=2, 6, 12 and NiNO.9HO over the temperature range 30nitrate hydrates show complex behaviour depending on the concentration. This behaviour is explained in terms of first hydration shell stability and NO3- penetration. This result contrasts with that for the equivalent correlation in nickel nitrate, and is taken as evidence for a more extensive free energy landscape of zinc nitrate hydrates. The results are also consistent with the known hydration properties of Zn2+ and Ni2+, and help explain why Zn2+ is biologically active in solution. PMID:14967238

Ansell, S; Neilson, G W

2004-02-15

173

DISTRIBUTION BEHAVIOR OF NEPTUNIUM AND PLUTONIUM BETWEEN ACID SOLUTIONS AND SOME ORGANIC EXTRACTANTS  

Microsoft Academic Search

The extractive properties of some organonitrogen and organophosphorus ; compounds for neptunium and plutoniuin in aqueous acid solutions were ; investigated under the following conditions: (1) The acid was generally HNO\\/sub ; 3\\/ although HâSOâ and HCl were also studied. (2) The valence of . ; neptunium and plutonium was generally (IV) although Np(V) and (VI) and Pu(lIl) ; and

Boyd Weaver; D. E. Horner

1960-01-01

174

7, 55535593, 2007 Nitrate aerosols  

E-print Network

ACPD 7, 5553­5593, 2007 Nitrate aerosols today and in 2030 S. E. Bauer et al. Title Page Abstract Discussions Nitrate aerosols today and in 2030: importance relative to other aerosol species and tropospheric, 5553­5593, 2007 Nitrate aerosols today and in 2030 S. E. Bauer et al. Title Page Abstract Introduction

Paris-Sud XI, Université de

175

Low temperature oxidation of plutonium  

SciTech Connect

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

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

2013-05-15

176

Tracking sources of unsaturated zone and groundwater nitrate contamination using nitrogen and oxygen stable isotopes at the Hanford site, Washington.  

PubMed

The nitrogen and oxygen isotopic compositions of nitrate in pore water extracts from unsaturated zone (UZ) core samples and groundwater samples indicate at least four potential sources of nitrate in groundwaters at the U.S. DOE Hanford Site in south-central Washington. Natural sources of nitrate identified include microbially produced nitrate from the soil column (delta15N of 4 - 8 per thousand, delta18O of -9 to 2 per thousand) and nitrate in buried caliche layers (delta15N of 0-8 per thousand, delta 18O of -6to 42 per thousand). Isotopically distinctindustrial sources of nitrate include nitric acid in low-level disposal waters (delta15N approximately per thousand, delta 18O approximately 23%o) per thousandnd co-contaminant nitrate in high-level radioactive waste from plutonium processing (6'5delta1of 8-33 % o, per thousand18delta oO -9 to 7%0). per thousandThe isotopic compositions of nitrate from 97 groundwater wells with concentrations up to 1290 mg/L NO3- have been analyzed. Stable isotope analyses from this study site, which has natural and industrial nitrate sources, provide a tool to distinguish nitrate sources in an unconfined aquiferwhere concentrations alone do not. These data indicate that the most common sources of high nitrate concentrations in groundwater at Hanford are nitric acid and natural nitrate flushed out of the UZ during disposal of low-level wastewater. Nitrate associated with high-level radioactive UZ contamination does not appear to be a major source of groundwater nitrate at this time. PMID:15952359

Singleton, Michael J; Woods, Katharine N; Conrad, Mark E; Depaolo, Donald J; Dresel, P Evan

2005-05-15

177

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

178

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

179

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

180

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

181

Ammonium nitrate explosive systems  

SciTech Connect

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.

Coburn, M.D.; Stinecipher, M.M.

1981-11-17

182

Microdistribution and Long-Term Retention of 239Pu (NO3)4 in the Respiratory Tracts of an Acutely Exposed Plutonium Worker and Experimental Beagle Dogs  

SciTech Connect

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 [239Pu (NO3)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 histological lung, lymph node, trachea, and nasal turbinate tissue sections. These studies showed that both the human and dogs had a non-uniform 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 sub-pleural 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 increase in cancer risk.

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

2012-11-01

183

Sulfide remediation by pulsed injection of nitrate into a low temperature Canadian heavy oil reservoir.  

PubMed

Sulfide formation by oil field sulfate-reducing bacteria (SRB) can be diminished by the injection of nitrate, stimulating the growth of nitrate-reducing bacteria (NRB). We monitored the field-wide injection of nitrate into a low temperature (approximately 30 degrees C) oil reservoir in western Canada by determining aqueous concentrations of sulfide, sulfate, nitrate, and nitrite, as well as the activities of NRB in water samples from 3 water plants, 2 injection wells, and 15 production wells over 2 years. The injection water had a low sulfate concentration (approximately 1 mM). Nitrate (2.4 mM, 150 ppm) was added at the water plants. Its subsequent distribution to the injection wells gave losses of 5-15% in the pipeline system, indicating that most was injected. Continuous nitrate injection lowered the total aqueous sulfide output of the production wells by 70% in the first five weeks, followed by recovery. Batchwise treatment of a limited section of the reservoir with high nitrate eliminated sulfide from one production well with nitrate breakthrough. Subsequent, field-wide treatment with week-long pulses of 14 mM nitrate gave breakthrough at an additional production well. However, this trend was reversed when injection with a constant dose of 2.4 mM (150 ppm) was resumed. The results are explained by assuming growth of SRB near the injection wellbore due to sulfate limitation. Injection of a constant nitrate dose inhibits these SRB initially. However, because of the constant, low temperature of the reservoir, SRB eventually grow back in a zone further removed from the injection wellbore. The resulting zonation (NRB closest to and SRB further away from the injection wellbore) can be broken by batch-wise increases in the concentration of injected nitrate, allowing it to re-enter the SRB-dominated zone. PMID:20000549

Voordouw, Gerrit; Grigoryan, Aleksandr A; Lambo, Adewale; Lin, Shiping; Park, Hyung Soo; Jack, Thomas R; Coombe, Dennis; Clay, Bill; Zhang, Frank; Ertmoed, Ryan; Miner, Kirk; Arensdorf, Joseph J

2009-12-15

184

Nitrate content and nitrate reductase activity in Rumex obtusifolius L  

Microsoft Academic Search

With Rumex obtusifolius L., the influence of some environmental conditions on nitrate uptake and reduction were investigated. Nitrate concentrations of plant material were determined by HPLC, the activity of nitrate reductase by an “in vivo” test. As optimal incubation medium, a buffer containing 0.04 M KNO3; 0.25 M KH2PO4; 1.5% propanol (v\\/v); pH 8.0 was found. Vacuum infiltration caused an

G. Gebauer; A. Melzer; H. Rehder

1984-01-01

185

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. PMID:22373430

2011-01-01

186

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

187

Effects of water characteristics on nitrate reduction by the Fe 0\\/CO 2 process  

Microsoft Academic Search

In this study, CO2 was bubbled into Fe0-contained solution to create an acidic environment favorable to reduction of aqueous nitrate under various water qualities. Results showed that nitrate of 30mgl?1 could be removed from solutions almost completely within 30min under the conditions of 2gFe0l?1 and CO2 bubbling flow rate of 200mlmin?1. It was observed from the Fe0\\/CO2 system that one

Chalermchai Ruangchainikom; Chih-Hsiang Liao; Jin Anotai; Ming-Tang Lee

2006-01-01

188

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

189

Plutonium solution analyzer  

SciTech Connect

A fully automated analyzer has been developed for plutonium solutions. It was assembled from several commercially available modules, is based upon segmented flow analysis, and exhibits precision about an order of magnitude better than commercial units (0.5%-O.05% RSD). The system was designed to accept unmeasured, untreated liquid samples in the concentration range 40-240 g/L and produce a report with sample identification, sample concentrations, and an abundance of statistics. Optional hydraulics can accommodate samples in the concentration range 0.4-4.0 g/L. Operating at a typical rate of 30 to 40 samples per hour, it consumes only 0.074 mL of each sample and standard, and generates waste at the rate of about 1.5 mL per minute. No radioactive material passes through its multichannel peristaltic pump (which remains outside the glovebox, uncontaminated) but rather is handled by a 6-port, 2-position chromatography-type loop valve. An accompanying computer is programmed in QuickBASIC 4.5 to provide both instrument control and data reduction. The program is truly user-friendly and communication between operator and instrument is via computer screen displays and keyboard. Two important issues which have been addressed are waste minimization and operator safety (the analyzer can run in the absence of an operator, once its autosampler has been loaded).

Burns, D.A.

1994-09-01

190

Effects of nitrate on the treatment of lead contaminated groundwater by nanoscale zerovalent iron.  

PubMed

Nanoscale zerovalent iron (nZVI) is efficient for removing Pb(2+) and nitrate from water. However, the influence of nitrate, a common groundwater anion, on Pb(2+) removal by nZVI is not well understood. In this study, we showed that under excess Fe(0) conditions (molar ratio of Fe(0)/nitrate>4), Pb(2+) ions were immobilized more quickly (<5min) than in nitrate-free systems (?15min) due to increasing pH. With nitrate in excess (molar ratio of Fe(0)/nitrate<4), nitrate stimulated the formation of crystal PbxFe3-xO4 (ferrite), which provided additional Pb(2+) removal. However, ?7% of immobilized Pb(2+) ions were released into aqueous phase within 2h due to ferrite deformation. Oxidation-reduction potential (ORP) values below -600mV correlated with excess Fe(0) conditions (complete Pb(2+) immobilization), while ORP values ?-475mV characterized excess nitrate conditions (ferrite process and Pb(2+) release occurrence). This study indicates that ORP monitoring is important for proper management of nZVI-based remediation in the subsurface to avoid lead remobilization in the presence of nitrate. PMID:25209830

Su, Yiming; Adeleye, Adeyemi S; Zhou, Xuefei; Dai, Chaomeng; Zhang, Weixian; Keller, Arturo A; Zhang, Yalei

2014-09-15

191

Plutonium removal limit for the disposition of plutonium-bearing materials  

Microsoft Academic Search

Recent changes in world politics have resulted in the United States reducing its nuclear weapons and stopping plutonium production. Prior plutonium production, dismantling warheads, and decontamination and decommissioning some facilities have produced plutonium-bearing materials which must continue to be managed. As each lot of material is processed, the processor must decide whether to remove the plutonium before discarding the material

W. C. White; B. Mowery; R. Felt; F. King; J. D. Hurley

1992-01-01

192

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 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...

2012-10-01

193

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

194

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 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...

2013-10-01

195

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 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...

2011-10-01

196

Processes for extraction of uranium and radium from uranium-containing ores using ferric nitrate  

SciTech Connect

A process is described for the extraction of both uranium and radium from uranium ores in the presence of an interfering sulfate ion resulting from the presence of sulfide therein by use of an aqueous ferric nitrate leachant including the steps of: (a) mechanically treating the finely ground ore for the removal of sulfide therefrom; (b) leaching the mechanically treated finely ground ore with aqueous acidic ferric nitrate solution in a concentration from 0.01 to 0.1M for the removal of uranium and radium therefrom to result in a liquid ferric nitrate leachate containing radium and uranium and a wet cake containing radium, uranium and ferric nitrate; (c) treating the ferric nitrate leachate to separate uranium and radium therefrom; (d) separately treating the wet cake for removal of retained ferric nitrate and the residual radium and uranium therefrom; and (e) recirculating a major portion of the ferric nitrate leachate from step (c) for the leaching of more of the mechanically treated finely ground ore.

Nirdosh, I.

1987-03-10

197

Design and fabrication of SGS plutonium standards  

SciTech Connect

This paper describes our experience of fabricating four sets of plutonium segmented gamma scanner (SGS) can standards. The fabrication involves careful planning, meticulous execution in weighing the plutonium oxide while minimizing contamination, chemical analyses by three different national laboratories to get accurate and independent plutonium concentrations, vertical scanning to assure mixing of the plutonium and the diluent, and finally the nondestructive verification measurement. By following these steps, we successfully fabricated 4 sets or 20 SGS can standards. 4 refs., 5 figs., 3 tabs.

Hsue, S.T.; Simmonds, S.M.; Longmire, V.L.; Long, S.M.

1991-01-01

198

C-Nitration of pyridine by the kyodai-nitration modified by the Bakke procedure. A simple route to 3-nitropyridine and mechanistic aspect of its formation  

Microsoft Academic Search

N-Nitropyridinium nitrate was generated in situ from pyridine, nitrogen dioxide and ozone in an inert organic solvent and subsequently treated with aqueous sodium hydrogen sulfite to afford 3-nitropyridine in good yield, together with sodium pyridine-4-sulfonate as a water-soluble by-product.

Hitomi Suzuki; Masao Iwaya; Tadashi Mori

1997-01-01

199

Complexation of Plutonium (IV) with Fluoride at Variable Temperatures  

SciTech Connect

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

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

2010-02-02

200

Estimating China's Production of Plutonium for Weapons  

Microsoft Academic Search

This article discusses the history of China's production of plutonium for nuclear weapons, and uses that history and analogies to the production process in the United States and Russia to estimate the amount of plutonium China produced at its two known facilities. That analysis leads to an estimate that China produced 2 to 5 tonnes of plutonium at these facilities

David Wright; Lisbeth Gronlund

2003-01-01

201

Robot vision system for remote plutonium disposition  

Microsoft Academic Search

Tons of weapons-usable plutonium has been declared surplus to the national security needs of the United States. The Plutonium Immobilization Program (PIP) is a US Department of Energy sponsored program to place excess plutonium in a stable form and make it unattractive for reuse. A vision system was developed as part of PIP robotic and remote systems development. This vision

Kriikku; Eric M. Kriikku

2000-01-01

202

Analysis of plutonium dioxide by coulometry  

SciTech Connect

Conditions for dissolution of plutonium dioxide have been determined. To transfer plutonium dioxides quantitatively in solution it should be heated with an HCl + HI mixture and boiled down three times in nitric acid. The disolution was monitored by potential scanning coulometry. The plutonium quantity was determined on a PKU-2 coulometric unit. Metrological parameters of the method have been evaluated.

Sklyarenko, I.S.; Andriets, V.V.; Chubukova, T.M.

1995-07-01

203

Nitrate assimilation in Lotus japonicus  

Microsoft Academic Search

This paper summarizes some recent advances in the understanding of nitrate assimilation in the model legume Lotus japonicus. First, different types of experimental evidence are presented that emphasize the importance of the root in the nitrate-reducing assimilatory processes in this plant. Secondly, the main results from an ethyl methanesulphonate muta- genesis programme are presented. In this programme, chlorate-resistant and photorespiratory

Antonio J. Marquez; Marco Betti; Margarita Garcia-Calderon; Peter Pal' ove-Balang; Pedro Diaz; Jorge Monza

2005-01-01

204

Nitrate losses from disturbed ecosystems  

Microsoft Academic Search

A systematic examination of nitrogen cycling in disturbed forest ecosystems demonstrates that eight processes, operating at three stages in the nitrogen cycle, could delay or prevent solution losses of nitrate from disturbed forests. An experimental and comparative study of nitrate losses from trenched plots in 19 forest sites throughout the United States suggests that four of these processes (nitrogen uptake

P. M. Vitousek; J. R. Gosz; C. C. Grier; J. M. Melillo; W. A. Reiners; R. L. Todd

1979-01-01

205

NITRATE LEACHING IN FLORIDA URBAN ENVIRONMENTS  

E-print Network

NITRATE LEACHING IN FLORIDA URBAN ENVIRONMENTS Michael Atkin Non-Thesis Research Paper Advisor: Dr....................................................................................3 Background- Nitrate Behavior in Soil and Florida Groundwater Vulnerability.......4 Urban Ecology in Urban Areas and Nitrate Reduction Strategies.......13 Conclusion

Ma, Lena

206

76 FR 70366 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...DHS-2008-0076] RIN 1601-AA52 Ammonium Nitrate Security Program AGENCY: National Protection...rulemaking (NPRM), entitled ``Ammonium Nitrate Security Program,'' which was published...62311). Under the proposed Ammonium Nitrate Security Program, the DHS will...

2011-11-14

207

76 FR 47238 - Ammonium Nitrate From Russia  

Federal Register 2010, 2011, 2012, 2013

...731-TA-856; Second Review] Ammonium Nitrate From Russia Determination On the basis...the antidumping duty order on ammonium nitrate from Russia would be likely to lead to...4249 (August 2011), entitled Ammonium Nitrate from Russia: Investigation No....

2011-08-04

208

76 FR 11273 - Ammonium Nitrate From Russia  

Federal Register 2010, 2011, 2012, 2013

...731-TA-856 (Second Review)] Ammonium Nitrate From Russia AGENCY: United States International...the suspended investigation on ammonium nitrate from Russia...the suspended investigation on ammonium nitrate from Russia would be likely to lead...

2011-03-01

209

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

210

Hanford-derived plutonium in Columbia River sediments  

Microsoft Academic Search

Mass spectrometry data on plutonium isolated from Columbia River sediments exhibit mean ratios of plutonium-240 to plutonium-242 consistent with those observed for integrated global fallout. Ratios of plutonium-240 to plutonium-239 show marked deviations from accepted fallout values, suggesting a second source of plutonium-239. This additional plutonium-239 arises from the decay of neptunium-239 produced in reactor effluent water from the old

T. M. Beasley; L. A. Ball; J. E. Andrews; J. E. Halverson

1981-01-01

211

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

212

Plutonium from Chernobyl in Poland  

Microsoft Academic Search

Samples of coniferous forest litter collected in POland, of known ?-emitters activity, have been analysed for ? emitting plutonium isotopes. Specific as well as surface activities of the samples have been determined. Chernobyl and global fallout components have been distinguished for each sample. The observed maximum surface activity for Chernobyl fallout is above 25 Bq m?2 (for all ?-emitting Pu

Jerzy W. Mietelski

1995-01-01

213

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

214

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

215

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

SciTech Connect

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

Totemeier, T.C.

1995-06-01

216

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

217

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

218

Nitrate and Prussic Acid Poisoning  

E-print Network

Nitrate and prussic acid poisoning in cattle are noninfectious conditions that can kill livestock. This publication explains the causes and symptoms of these conditions as well as preventive measures and sampling and testing steps....

Stichler, Charles; Reagor, John C.

2001-09-05

219

The radiological hazard of plutonium isotopes and specific plutonium mixtures  

SciTech Connect

The US Department of Energy defines the hazard categories of its nuclear facilities based upon the potential for accidents to have significant effects on specific populations and the environment. In this report, the authors consider the time dependence of hazard category 2 (significant on-site effects) for facilities with inventories of plutonium isotopes and specific weapons-grade and heat-source mixtures of plutonium isotopes. The authors also define relative hazard as the reciprocal of the hazard category 2 threshold value and determine its time dependence. The time dependence of both hazard category 2 thresholds and relative hazards are determined and plotted for 10,000 years to provide useful information for planning long-term storage or disposal facilities.

Heindel, G.; Clow, J.; Inkret, W.; Miller, G.

1995-11-01

220

Nitrate Removal in NITREXTM Permeable Reactive Barriers  

E-print Network

Nitrate Removal in NITREXTM Permeable Reactive Barriers: Investigating Denitrification Using a 15 (particularly of nitrate) to aquatic systems is a growing problem. The NITREXTM Permeable Reactive Barrier (PRB) is a system for removing nitrate in groundwater. We investigated the nitrate removal processes and hydrology

Vallino, Joseph J.

221

What Limits Nitrate Reduction in Leaves?  

Microsoft Academic Search

The observation that even drastic over- or underexpression of nitrate reductase (NR) has little effect on biomass production suggests that nitrate reduction in situ and extractable NR activity are not strictly coupled. Rates of nitrate reduction in detached spinach leaves are often, but not always, much lower than NR activity measured in leaf extracts under substrate (nitrate and NADH) saturation.

Werner M. Kaiser; Maria Stoimenova; Hui-Min Man

222

Studies of nitrate reductase in marine phytoplankton  

Microsoft Academic Search

Certain marine phytoplankton contain the enzyme nitrate rcductase when growing on nitrate, but only low levels of enzyme were found during growth with ammonium or when the nitrogen source was depleted. Netted samples of oceanic phytoplankton contained the enzyme when taken from waters with nitrate concentrations 2-10 PM. Ammonium was assimilated in preference to nitrate in phytoplankton cultures supplied with

R. W. EPPLEY; J. L. COATSWORTH; LUCIA SOLÓRZANO

1969-01-01

223

Viscosity of Molten Sodium Nitrate  

NASA Astrophysics Data System (ADS)

New experimental data for the viscosity of molten sodium nitrate from its melting point up to 752 K, at atmospheric pressure, with an estimated uncertainty of 2.1%, were measured with an oscillating cup viscometer. A preliminary reference correlation and reference data are proposed, based on the best available data for the viscosity of molten sodium nitrate, for temperatures between 590 and 750 K, with an estimated absolute uncertainty of 0.066 mPa · s ( k = 2).

Nunes, V. M. B.; Lourenço, M. J. V.; Santos, F. J. V.; de Castro, C. A. Nieto

2006-11-01

224

Deliquescence, Efflorescence, and Water Activity in Ammonium Nitrate and Mixed Ammonium Nitrate/Succinic Acid Microparticles  

E-print Network

Deliquescence, Efflorescence, and Water Activity in Ammonium Nitrate and Mixed Ammonium Nitrate of ammonium nitrate/water and mixed ammonium nitrate/succinic acid/water microparticles. The water activity of ammonium nitrate microparticles is determined as a function of composition down to 12% relative humidity

225

Adsorption of uranium from aqueous solutions using activated carbon  

SciTech Connect

The adsorption of uranium from aqueous solution has been investigated using conventional commercially available activated carbons. It was found that treatment with hot nitric acid oxidized the surface of activated carbon and significantly increased the adsorption capacity for uranium in near-neutral and slightly acidic nitrate solutions. Equilibrium data were fitted to a simplified Freundlich isotherm for the purpose of comparison of oxidized and as-received samples. The decontamination of aqueous solutions was investigated in small column experiments. An ion-exchange mechanism of uranium sorption from aqueous solution is discussed. 43 refs., 11 figs., 1 tab.

Abbasi, W.A. (Pakistan Atomic Energy Commission, Islamabad (Pakistan)); Streat, M. (Loughborough Univ. of Technology, Leicestershire (United Kingdom))

1994-06-01

226

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

227

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

228

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

229

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

230

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

231

Alpha-plutonium's Grüneisen parameter.  

PubMed

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

Ledbetter, Hassel; Lawson, Andrew; Migliori, Albert

2010-04-28

232

Hydrogen-based tubular catalytic membrane for removing nitrate from groundwater.  

PubMed

A porous tubular ceramic membrane coated with palladium-cupper (Pd-Cu) catalyst on its surface was prepared and evaluated for catalytic reduction of nitrate from groundwater. Nitrate reduction activity and selectivity with the catalytic membrane were compared with Pd-Cu/Al2O3 catalyst particles. The catalytic membrane reactor exhibited a better selectivity by enabling an effective control of hydrogen gas, thus minimizing ammonium production. No leaching of palladium and copper into aqueous phase was observed, thereby indicating a high chemical stability of the metallic ions on the carrier support. This was also evidenced by the X-ray photoelectron spectroscopy (XPS) profiles of fresh and used catalysts, which showed no significant difference in surface compositions. Due to its higher selectivity in nitrate reduction and better flexibility in terms of operating conditions, the tubular catalytic ceramic membrane could be useful in removing nitrate from groundwater. PMID:15116881

Chen, Y X; Zhang, Y; Liu, H Y; Sharma, K R; Chen, G H

2004-02-01

233

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

Microsoft Academic Search

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

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

2006-01-01

234

Decomposition kinetics of plutonium hydride  

Microsoft Academic Search

Kinetic data for decomposition of PuH⁠ââ provides insight into a possible mechanism for the hydriding and dehydriding reactions of plutonium. The fact that the rate of the hydriding reaction, K\\/sub H\\/, is proportional to P¹² and the rate of the dehydriding process, K\\/sub D\\/, is inversely proportional to P¹² suggests that the forward and reverse reactions proceed by opposite

J. M. Haschke; J. L. Stakebake

1979-01-01

235

Plutonium Immobilization Program cold pour tests  

Microsoft Academic Search

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 to carry out the disposition of excess weapons-grade plutonium. This program uses the can-in-canister (CIC) approach. CIC involves encapsulating plutonium in ceramic forms (or pucks), placing the pucks in sealed stainless steel cans, placing

G. L. Hovis; M. W. Stokes; M. E. Smith; J. W. Wong

1999-01-01

236

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

237

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

238

Synthesis of nanosized CuCrO 2 porous powders via a self-combustion glycine nitrate process  

Microsoft Academic Search

The glycine nitrate process has been successfully employed to prepare nanosized, porous, stoichiometric, homogeneous CuCrO2 powders without ambient control. In this method, a precursor solution was prepared by mixing glycine with an aqueous solution of blended (Cu–Cr) metal–nitrates in their stoichiometric ratios. The glycine-mixed precursor solution was first heated in a beaker to evaporate excess water for forming a viscous

Te-Wei Chiu; Bing-Sheng Yu; Yuh-Ruey Wang; Kun-Te Chen; Yu-Te Lin

2011-01-01

239

Effects of the Physical State of Tropospheric Ammonium-Sulfate-Nitrate Particles on Global Aerosol Direct Radiative Forcing  

Microsoft Academic Search

The effect of aqueous versus crystalline sulfate-nitrate-ammonium tropospheric particles on global aerosol direct radiative forcing is assessed. A global three-dimensional chemical transport model predicts sulfate, nitrate, and ammonium aerosol mass. An aerosol thermodynamics model is called twice, once for the upper side (US) and once for lower side (LS) of the hysteresis loop of particle phase. On the LS, the

S. T. Martin; H.-M. Hung; R. J. Park; D. J. Jacob; R. J. D. Spurr; K. V. Chance; M. Chin

2004-01-01

240

Effects of the physical state of tropospheric ammonium-sulfate-nitrate particles on global aerosol direct radiative forcing  

Microsoft Academic Search

The effect of aqueous versus crystalline sulfate-nitrate-ammonium tropospheric particles on global aerosol direct radiative forcing is assessed. A global three-dimensional chemical transport model predicts sulfate, nitrate, and ammonium aerosol mass. An aerosol thermodynamics model is called twice, once for the upper side (US) and once for lower side (LS) of the hysteresis loop of particle phase. On the LS, the

S. T. Martin; H.-M. Hung; R. J. Park; D. J. Jacob; R. J. D. Spurr; K. V. Chance; V. Chin

2003-01-01

241

Nitrate transport is independent of NADH and NAD(P)H nitrate reductases in barley seedlings  

NASA Technical Reports Server (NTRS)

Barley (Hordeum vulgare L.) has NADH-specific and NAD(P)H-bispecific nitrate reductase isozymes. Four isogenic lines with different nitrate reductase isozyme combinations were used to determine the role of NADH and NAD(P)H nitrate reductases on nitrate transport and assimilation in barley seedlings. Both nitrate reductase isozymes were induced by nitrate and were required for maximum nitrate assimilation in barley seedlings. Genotypes lacking the NADH isozyme (Az12) or the NAD(P)H isozyme (Az70) assimilated 65 or 85%, respectively, as much nitrate as the wild type. Nitrate assimilation by genotype (Az12;Az70) which is deficient in both nitrate reductases, was only 13% of the wild type indicating that the NADH and NAD(P)H nitrate reductase isozymes are responsible for most of the nitrate reduction in barley seedlings. For all genotypes, nitrate assimilation rates in the dark were about 55% of the rates in light. Hypotheses that nitrate reductase has direct or indirect roles in nitrate uptake were not supported by this study. Induction of nitrate transporters and the kinetics of net nitrate uptake were the same for all four genotypes indicating that neither nitrate reductase isozyme has a direct role in nitrate uptake in barley seedlings.

Warner, R. L.; Huffaker, R. C.

1989-01-01

242

Thermal decomposition of nitrated tributyl phosphate  

SciTech Connect

Extended contact between heated mixtures of tri-n-butyl phosphate (TBP) and aqueous solutions of nitric acid and/or heavy metal nitrate salts at elevated temperatures can lead to exothermic reactions of explosive violence. Most solvent extraction operations are conducted at ambient conditions without heating TBP and have been performed safely for decades, but several explosions involving TBP have occurred in the US, Canada, and the former Soviet Union. This investigation was undertaken to characterize the products of thermal decomposition of both single- and two-phase mixtures of TBP, nitric acid, and water under a variety of conditions. The data indicate that the extent of reaction and the rate of gaseous product formation are affected by the presence of Zr{sup 4+}, distillation compared with reflux conditions, temperature, water/HNO{sub 3} and HNO{sub 3}/TBP ratios, and whether the decomposition occurs under constant pressure or constant volume conditions. Higher reaction temperatures accelerate the rate of decomposition, but the extent of decomposition, as measured by the quantity of gaseous products, was greater at lower temperatures when the decomposition was performed under distillation conditions. Higher gas production occurs under reflux conditions, lower H{sub 2}O/HNO{sub 3} ratios, and when a separate water-HNO{sub 3} phase is initially present. The major gaseous products include N{sub 2}, CO, CO{sub 2}, NO, and N{sub 2}O. Measurable amounts of NO{sub 2} were not present in the final product mixture, although an orange color suggesting the presence of NO{sub 2} was observed in the early stages of decomposition. The major liquid products were dibutyl phosphoric acid, butyl nitrate, and water. Small amounts of C{sub 1}-C{sub 4} carboxylic acids were also present. Because of the small sample sizes that were employed and the isothermal conditions of the decomposition, runaway reactions were not observed. Some possible reaction pathways are considered.

Hou, Y.; Barefield, E.K.; Tedder, D.W.; Abdel-Khalik, S.I. [Georgia Inst. of Technology, Atlanta, GA (United States)

1996-03-01

243

LANL Plutonium-Processing Facilities National Security  

E-print Network

- tinide chemistry; nuclear materials separation, processing, and recovery; plutonium metallurgy, preparation, casting, fabrication, and recovery; machining and metallurgy laboratories; and de- structive

244

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

245

Imbalance between vertical nitrate flux and nitrate assimilation on a continental shelf: Implications of nitrification  

Microsoft Academic Search

Nitrate assimilation and diapycnal nitrate flux were simultaneously determinedPresence of amoA indicated nitrification within the euphotic zoneNitrate-based new production can be overestimated by the nitrification

Takuhei Shiozaki; Ken Furuya; Hiroyuki Kurotori; Taketoshi Kodama; Shigenobu Takeda; Takahiro Endoh; Yutaka Yoshikawa; Joji Ishizaka; Takeshi Matsuno

2011-01-01

246

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

247

Mechanism of enhanced nitrate reduction via micro-electrolysis at the powdered zero-valent iron/activated carbon interface.  

PubMed

Nitrate reduction by zero-valent iron (Fe(0)) powder always works well only at controlled pH lower than 4 due to the formation of iron (hydr)oxides on its surface. Fe(0) powder combined with activated carbon (AC), i.e., Fe(0)/AC micro-electrolysis system, was first introduced to enhance nitrate reduction in aqueous solution. Comparative study was carried out to investigate nitrate reduction by Fe(0)/AC system and Fe(0) under near-neutral conditions, showing that the Fe(0)/AC system successfully reduced nitrate even at initial pH 6 with the reduction efficiency of up to 73%, whereas for Fe(0) only ?10%. The effect of Fe(0) to AC mass ratio on nitrate reduction efficiency was examined. Easier nitrate reduction was achieved with more contact between Fe(0) and AC as the result of decreasing Fe(0) to AC mass ratio. Ferrous ion and oxidation-reduction potential were measured to understand the mechanism of enhanced nitrate reduction by Fe(0)/AC micro-electrolysis. The results suggest that a relative potential difference drives much more electrons from Fe(0) to AC, thus generating adsorbed atomic hydrogen which makes it possible for nitrate to be reduced at near-neural pH. Fe(0)/AC micro-electrolysis thus presents a great potential for practical application in nitrate wastewater treatment without excessive pH adjustment. PMID:25217726

Luo, Jinghuan; Song, Guangyu; Liu, Jianyong; Qian, Guangren; Xu, Zhi Ping

2014-12-01

248

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

249

Factors Controlling Redox Speciation of Plutonium and Neptunium in Extraction Separation Processes  

SciTech Connect

The objective of the project was to examine the factors controlling redox speciation of plutonium and neptunium in UREX+ extraction in terms of redox potentials, redox mechanism, kinetics and thermodynamics. Researchers employed redox-speciation extractions schemes in parallel to the spectroscopic experiments. The resulting distribution of redox species w studied uring spectroscopic, electrochemical, and spectro-electrochemical methods. This work reulted in collection of data on redox stability and distribution of redox couples in the nitric acid/nitrate electrolyte and the development of redox buffers to stabilize the desired oxidation state of separated radionuclides. The effects of temperature and concentrations on the redox behavior of neptunium were evaluated.

Paulenova, Alena [Principal Investigator; Vandegrift, III, George F. [Collaborator

2013-09-24

250

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

SciTech Connect

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

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

2007-07-01

251

[Glyceryl nitrates may cause hypertension].  

PubMed

The patient was an 82-year-old woman with orthostatism, who was administrated one normal dose of glyceryl nitrate as a part of a tilt table test. The following ten minutes after administration, a paradoxical and significant blood pressure response was registered in the form of a rise to 205/111 mmHg. The conclusion was that her response was a paradoxical response to glyceryl nitrate, orthostatism and a pathological response to massage of the carotid artery. This is the third reported case on paradoxical hypertension induced by glyceryl nitrates. It is speculated that dysfunction of the cerebral bloodflow autoregulation may be one of the causes of this phenomenon. PMID:21586249

Mørup, Peter; Levinsen, Tine Holbæk; Hovind, Peter

2011-05-16

252

Acetonyltriphenyl-phospho-nium nitrate  

PubMed Central

Crystals of the title salt, C21H20OP+·NO3 ?, are composed of acetonyltriphenyl­phospho­nium cations and nitrate anions that mainly inter­act through electrostatic forces. The P atom in the cation has a slightly distorted tetra­hedral environment, with C—P—C angles ranging from 104.79?(7) to 112.59?(6)°. The sum of O—N—O angles of the nitrate anion is 359.99°, reflecting its trigonal–planar character. C—H?O hydrogen bonds help to consolidate the crystal packing. PMID:23424568

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

2013-01-01

253

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

2013-02-01

254

Nitrate Trends in Minnesota Rivers  

USGS Publications Warehouse

The objective of this study was to assess long-term trends (30 to 35 years) of flow-adjusted concentrations of nitrite+nitrate-N (hereinafter referred to as nitrate) in a way that would allow us to discern changing trends. Recognizing that these trends are commonly different from one river to another river and from one part of the state to another, our objective was to examine as many river monitoring sites across the state as possible for which sufficient long term streamflow and concentration data were available.

Wall, Dave; Christopherson, Dave; Lorenz, Dave; Martin, Gary

2013-01-01

255

Nitration of the Birch Pollen Allergen Bet v 1.0101: Efficiency and Site-Selectivity of Liquid and Gaseous Nitrating Agents  

PubMed Central

Nitration of the major birch pollen allergen Bet v 1 alters the immune responses toward this protein, but the underlying chemical mechanisms are not yet understood. Here we address the efficiency and site-selectivity of the nitration reaction of recombinant protein samples of Bet v 1.0101 with different nitrating agents relevant for laboratory investigations (tetranitromethane, TNM), for physiological processes (peroxynitrite, ONOO–), and for the health effects of environmental pollutants (nitrogen dioxide and ozone, O3/NO2). We determined the total tyrosine nitration degrees (ND) and the NDs of individual tyrosine residues (NDY). High-performance liquid chromatography coupled to diode array detection and HPLC coupled to high-resolution mass spectrometry analysis of intact proteins, HPLC coupled to tandem mass spectrometry analysis of tryptic peptides, and amino acid analysis of hydrolyzed samples were performed. The preferred reaction sites were tyrosine residues at the following positions in the polypeptide chain: Y83 and Y81 for TNM, Y150 for ONOO–, and Y83 and Y158 for O3/NO2. The tyrosine residues Y83 and Y81 are located in a hydrophobic cavity, while Y150 and Y158 are located in solvent-accessible and flexible structures of the C-terminal region. The heterogeneous reaction with O3/NO2 was found to be strongly dependent on the phase state of the protein. Nitration rates were about one order of magnitude higher for aqueous protein solutions (?20% per day) than for protein filter samples (?2% per day). Overall, our findings show that the kinetics and site-selectivity of nitration strongly depend on the nitrating agent and reaction conditions, which may also affect the biological function and adverse health effects of the nitrated protein. PMID:24517313

2014-01-01

256

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

257

Japan's spent fuel and plutonium management challenge  

Microsoft Academic Search

Japan's commitment to plutonium recycling has been explicitly stated in its long-term program since 1956. Despite the clear cost disadvantage compared with direct disposal or storage of spent fuel, the Rokkasho reprocessing plant started active testing in 2006. Japan's cumulative consumption of plutonium has been only 5tons to date and its future consumption rate is still uncertain. But once the

Tadahiro Katsuta; Tatsujiro Suzuki

2011-01-01

258

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

259

Plutonium Finishing Plant operational readiness review  

Microsoft Academic Search

This plan describes the readiness review process to be used to meet the objectives to support the restart of the Plutonium Finishing Plant (PFP) to convert the chemically-acting plutonium-bearing materials to a form suitable for processing in the remote mechanical C'' (RMC) line. The scope of this plan will cover the restart readiness review needs of the PFP Material Stabilization

Eschenbaum

1992-01-01

260

Reactive sintering of plutonium-bearing titanates.  

SciTech Connect

Titanate ceramics are being developed for the immobilization of weapons-grade plutonium. These multi-phase ceramics are intended to be both corrosion and proliferation resistant. Reactive sintering techniques were refined to reproducibly provide titanate ceramics for further characterization and testing. Plutonium-bearing pyrochlore-rich composites were consolidated to greater than 90% of their theoretical density.

Hash, M. C.

1999-06-24

261

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

262

Constructed Marshes for Nitrate Removal  

Microsoft Academic Search

Large numbers of free water surface treatment wetlands are in use for nitrate reduction. Target applications are field runoff, river and stream improvement, and enhancement of wastewater treatment plants. In total, an extensive database now exists, in many publications and operating reports. Microcosms and mesocosms are not included here because of the lack of transferability to design. A first-order areal

Robert H. Kadlec

2012-01-01

263

Constructed Marshes for Nitrate Removal  

Microsoft Academic Search

Large numbers of free water surface treatment wetlands are in use for nitrate reduction. Target applications are field runoff, river and stream improvement, and enhancement of wastewater treatment plants. In total, an extensive database now exists, in many publications and operating reports. Microcosms and mesocosms are not included here, because of lack of transferability to design. A first-order areal model

Robert H. Kadlec

2011-01-01

264

On the influence of molecular structure on the conductivity of electrolyte solutions - sodium nitrate in water  

E-print Network

Theoretical calculations of the conductivity of sodium nitrate in water are presented and compared with experimental measurements. The method of direct correlation force in the framework of the interionic theory is used for the calculation of transport properties in connection with the associative mean spherical approximation (AMSA). The effective interactions between ions in solutions are derived with the help of Monte Carlo and Molecular Dynamics calculations on the Born-Oppenheimer level. This work is based on earlier theoretical and experimental studies of the structure of concentrated aqueous sodium nitrate solutions.

H. Krienke

2013-12-16

265

A Novel Chemical Nitrate Destruction Process  

SciTech Connect

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

Dziewinski, J.; Marczak, S.

1999-03-01

266

Plutonium Uptake and Distribution in Mammalian Cells: Molecular vs Polymeric Plutonium  

PubMed Central

Purpose To study the cellular responses to molecular and polymeric forms of plutonium using PC12 cells derived from rat adrenal glands. Materials and methods Serum starved PC12 cells were exposed to polymeric and molecular forms of plutonium for three hours. Cells were washed with 10 mM EGTA, 100 mM NaCl at pH 7.4 to remove surface sorbed plutonium. Localization of plutonium in individual cell was quantitatively analyzed by synchrotron X-ray fluorescence (XRF) microscopy. Results Molecular plutonium complexes introduced to cell growth media in the form of NTA, citrate, or transferrin complexes were taken up by PC12 cells, and mostly co-localized with iron within the cells. Polymeric plutonium prepared separately was not internalized by PC12 cells but it was always found on the cell surface as big agglomerates; however polymeric plutonium formed in situ was mostly found within the cells as agglomerates. Conclusions PC12 cells can differentiate molecular and polymeric forms of plutonium. Molecular plutonium is taken up by PC12 cells and mostly co-localized with iron but aged polymeric plutonium is not internalized by the cells. PMID:21770702

ARYAL, BAIKUNTHA P.; GORMAN-LEWIS, DREW; PAUNESKU, TATJANA; WILSON, RICHARD E.; LAI, BARRY; VOGT, STEFAN; WOLOSCHAK, GAYLE E.; JENSEN, MARK P.

2013-01-01

267

Comparative Studies on Nitrate Reductase in Agrostemma githago Induced by Nitrate and Benzyladenine 12  

PubMed Central

NADH-nitrate reductase activity in excised embryos of Agrostemma githago develops in response to nitrate as well as benzyladenine. Induction of nitrate reductase by benzyladenine was much more susceptible to inhibition by a mixture of amino acid analogues and by cordycepin than induction by nitrate. In contrast, only induction of nitrate-nitrate reductase was decreased by chloramphenicol. NADH-cytochrome c reductase and reduced flavin mono-nucleotide-nitrate reductase activities were found to be associated with NADH-nitrate reductase and were induced by both nitrate and benzyladenine. When a partially purified enzyme sample was centrifuged in a linear 5 to 20% sucrose density gradient, a minor and a major band of NADH-cytochrome c reductase activity were observed. NADH-nitrate reductase cosedimented with the major band. The characteristics of nitrate-nitrate reductase and benzyl-adenine-nitrate reductase were compared by four methods but no differences could be detected: (a) Both enzymes sedimented with the same velocity during sucrose density gradient centrifugation. (b) Their distribution among fractions obtained by differential precipitation with (NH4)2SO4 was identical. (c) The elution profile of nitrate-nitrate reductase and benzyl-adenine-nitrate reductase after chromatography on diethyl-aminoethyl Sephadex A-25 columns showed no significant difference. (d) On polyacrylamide gel, the electrophoretic migration of the two enzymes was also identical. PMID:16658982

Dilworth, Machi Fukuyama; Kende, Hans

1974-01-01

268

Comparative Studies on Nitrate Reductase in Agrostemma githago Induced by Nitrate and Benzyladenine.  

PubMed

NADH-nitrate reductase activity in excised embryos of Agrostemma githago develops in response to nitrate as well as benzyladenine. Induction of nitrate reductase by benzyladenine was much more susceptible to inhibition by a mixture of amino acid analogues and by cordycepin than induction by nitrate. In contrast, only induction of nitrate-nitrate reductase was decreased by chloramphenicol.NADH-cytochrome c reductase and reduced flavin mono-nucleotide-nitrate reductase activities were found to be associated with NADH-nitrate reductase and were induced by both nitrate and benzyladenine. When a partially purified enzyme sample was centrifuged in a linear 5 to 20% sucrose density gradient, a minor and a major band of NADH-cytochrome c reductase activity were observed. NADH-nitrate reductase cosedimented with the major band.The characteristics of nitrate-nitrate reductase and benzyl-adenine-nitrate reductase were compared by four methods but no differences could be detected: (a) Both enzymes sedimented with the same velocity during sucrose density gradient centrifugation. (b) Their distribution among fractions obtained by differential precipitation with (NH(4))(2)SO(4) was identical. (c) The elution profile of nitrate-nitrate reductase and benzyl-adenine-nitrate reductase after chromatography on diethyl-aminoethyl Sephadex A-25 columns showed no significant difference. (d) On polyacrylamide gel, the electrophoretic migration of the two enzymes was also identical. PMID:16658982

Dilworth, M F; Kende, H

1974-12-01

269

Alpha radiation effects on weapons-grade plutonium encapsulating materials  

Microsoft Academic Search

The scientific understanding of material problems in the long-term storage of plutonium pits is investigated using experimental and theoretical models. The durability of the plutonium pit depends on the integrity of the metal cladding that encapsulates the plutonium. Given sufficient time, the energetic alpha particles (helium nuclei) produced by nuclear decay of the plutonium would degrade the mechanical strength of

Mehmet Saglam

2000-01-01

270

TERTIARY AMINE EXTRACTION OF PLUTONIUM FROM NITRIC ACID SOLUTIONS  

Microsoft Academic Search

Data are presented to show the effect of pertinent variables on the ; extraction of plutonium. The extraction of plutonium(III) and (VI) is shown to ; be small. The data on the extraction of plutonium(IV) by several amines are ; presented and discussed. Some experiments on the effect of the organic diluent ; on the solubility of the plutonium(IV)-amine complex

1958-01-01

271

Preparation of thin ceramic films via an aqueous solution route  

DOEpatents

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

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

1989-01-01

272

Plutonium focus area. Technology summary  

SciTech Connect

The Assistant Secretary for the Office of Environmental Management (EM) at the U.S. Department of Energy (DOE) chartered the Plutonium Focus Area (PFA) in October 1995. The PFA {open_quotes}...provides for peer and technical reviews of research and development in plutonium stabilization activities...{close_quotes} In addition, the PFA identifies and develops relevant research and technology. The purpose of this document is to focus attention on the requirements used to develop research and technology for stabilization, storage, and preparation for disposition of nuclear materials. The PFA Technology Summary presents the approach the PFA uses to identify, recommend, and review research. It lists research requirements, research being conducted, and gaps where research is needed. It also summarizes research performed by the PFA in the traditional research summary format. This document encourages researchers and commercial enterprises to do business with PFA by submitting research proposals or {open_quotes}white papers.{close_quotes} In addition, it suggests ways to increase the likelihood that PFA will recommend proposed research to the Nuclear Materials Stabilization Task Group (NMSTG) of DOE.

NONE

1997-09-01

273

Automated amperometric plutonium assay system  

SciTech Connect

The amperometric titration for plutonium assay has been used in the nuclear industry for over twenty years and has been in routine use at the Hanford Engineering Development Laboratory since 1976 for the analysis of plutonium oxide and mixed oxide fuel material for the Fast Flux Test Facility. It has proven itself to be an accurate and reliable method. The method may be used as a direct end point titration or an excess of titrant may be added and a back titration performed to aid in determination of the end point. Due to the slowness of the PuVI-FeII reaction it is difficult to recognize when the end point is being approached and is very time consuming if the current is allowed to decay to the residual value after each titrant addition. For this reason the back titration in which the rapid FeII-CrVI reaction occurs is used by most laboratories. The back titration is performed by the addition of excess ferrous solution followed by two measured aliquots of standard dichromate with measurement of cell current after each addition.

Burt, M.C.

1985-01-01

274

Nitrate toxicity in Siberian sturgeon ( Acipenser baeri)  

Microsoft Academic Search

Excess nitrate in aquaculture has traditionally been reduced by water exchange. Current trends in environmental regulation, however, are limiting the amount of water which may be consumed or discharged, reducing the ability to use large influxes of water to remediate excess nitrate. This will create significant challenges for the aquaculture community, as the etiology, effects and tolerable thresholds of nitrate

H. J. Hamlin

2006-01-01

275

3, 59195976, 2003 The nitrate aerosol  

E-print Network

ACPD 3, 5919­5976, 2003 The nitrate aerosol field over Europe M. Schaap et al. Title Page Abstract/5919/ © European Geosciences Union 2003 Atmospheric Chemistry and Physics Discussions The nitrate aerosol field.schaap@phys.uu.nl) 5919 #12;ACPD 3, 5919­5976, 2003 The nitrate aerosol field over Europe M. Schaap et al. Title Page

Paris-Sud XI, Université de

276

8, 48114829, 2008 SOA and nitrate  

E-print Network

ACPD 8, 4811­4829, 2008 SOA and nitrate volatility in Mexico City C. J. Hennigan et al. Title Page of newly formed nitrate and water soluble organic aerosol in Mexico City C. J. Hennigan1 , A. P. Sullivan2 Geosciences Union. 4811 #12;ACPD 8, 4811­4829, 2008 SOA and nitrate volatility in Mexico City C. J. Hennigan

Paris-Sud XI, Université de

277

6, 14551480, 2006 Modelling of nitrate  

E-print Network

ACPD 6, 1455­1480, 2006 Modelling of nitrate particles G. Myhre and A. Grini Title Page Abstract Discussions Modelling of nitrate particles: importance of sea salt G. Myhre1,2 and A. Grini1 1 Department Correspondence to: G. Myhre (gunnar.myhre@geo.uio.no) 1455 #12;ACPD 6, 1455­1480, 2006 Modelling of nitrate

Boyer, Edmond

278

Spatial Inference of Nitrate Concentrations in Groundwater  

E-print Network

Spatial Inference of Nitrate Concentrations in Groundwater DAWN B. WOODARD, ROBERT L. WOLPERT on a nonparametric spatial statistical model. We apply this method to estimate nitrate concentra- tions of the fine-scale estimated nitrate concentration is obtained, as well as maps of the estimated county

West, Mike

279

8, 1103911062, 2008 Nitrate in polar ice  

E-print Network

ACPD 8, 11039­11062, 2008 Nitrate in polar ice E. W. Wolff et al. Title Page Abstract Introduction Chemistry and Physics Discussions Reassessment of the factors controlling temporal profiles of nitrate Geosciences Union. 11039 #12;ACPD 8, 11039­11062, 2008 Nitrate in polar ice E. W. Wolff et al. Title Page

Paris-Sud XI, Université de

280

6, 1071310731, 2006 Nitrate photolysis on  

E-print Network

ACPD 6, 10713­10731, 2006 Nitrate photolysis on ice surfaces T. Bartels-Rausch and D. J. Donaldson Chemistry and Physics Discussions HONO and NO2 evolution from irradiated nitrate-doped ice and frozen nitrate solutions T. Bartels-Rausch1,* and D. J. Donaldson1 1 University of Toronto, Ontario M5S 3H6

Paris-Sud XI, Université de

281

21 CFR 172.170 - Sodium nitrate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Sodium nitrate. 172.170 Section 172.170 Food and...CONSUMPTION Food Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified...

2012-04-01

282

21 CFR 172.160 - Potassium nitrate.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

283

76 FR 62311 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...DHS-2008-0076] RIN 1601-AA52 Ammonium Nitrate Security Program AGENCY: National Protection...rulemaking (NPRM), entitled ``Ammonium Nitrate Security Program,'' which was published...regulate the sale and transfer of ammonium nitrate pursuant to section 563 of the...

2011-10-07

284

Nitrate removal from drinking water -- Review  

Microsoft Academic Search

Nitrate concentrations in surface water and especially in ground water have increased in Canada, the US, Europe, and other areas of the world. This trend has raised concern because nitrates cause methemoglobiinemia in infants. Several treatment processes including ion exchange, biological denitrification, chemical denitrification, reverse osmosis, electrodialysis, and catalytic denitrification can remove nitrates from water with varying degrees of efficiency,

Anoop Kapoor; T. Viraraghavan

1997-01-01

285

Efflux Of Nitrate From Hydroponically Grown Wheat  

NASA Technical Reports Server (NTRS)

Report describes experiments to measure influx, and efflux of nitrate from hydroponically grown wheat seedlings. Ratio between efflux and influx greater in darkness than in light; increased with concentration of nitrate in nutrient solution. On basis of experiments, authors suggest nutrient solution optimized at lowest possible concentration of nitrate.

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

1992-01-01

286

21 CFR 172.160 - Potassium nitrate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Potassium nitrate. 172.160 Section 172.160 Food and...Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing agent in the...

2012-04-01

287

21 CFR 172.160 - Potassium nitrate.  

...2014-04-01 2014-04-01 false Potassium nitrate. 172.160 Section 172.160 Food and...Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing agent in the...

2014-04-01

288

21 CFR 172.170 - Sodium nitrate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Sodium nitrate. 172.170 Section 172.170 Food and...CONSUMPTION Food Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified...

2013-04-01

289

21 CFR 172.170 - Sodium nitrate.  

...2014-04-01 2014-04-01 false Sodium nitrate. 172.170 Section 172.170 Food and...CONSUMPTION Food Preservatives § 172.170 Sodium nitrate. The food additive sodium nitrate may be safely used in or on specified...

2014-04-01

290

DO ORGANIC FARMING PRACTICES REDUCE NITRATE LEACHING?  

Microsoft Academic Search

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

Holger Kirchmann; Lars Bergström

2001-01-01

291

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

Code of Federal Regulations, 2013 CFR

...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate...

2013-10-01

292

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

Code of Federal Regulations, 2012 CFR

...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate...

2012-10-01

293

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

Code of Federal Regulations, 2011 CFR

...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate...

2011-10-01

294

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

Code of Federal Regulations, 2010 CFR

...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate...

2010-10-01

295

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

PubMed

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

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

2013-01-01

296

Nitrated fatty acids: Synthesis and measurement  

PubMed Central

Nitrated fatty acids are the product of nitrogen dioxide reaction with unsaturated fatty acids. The discovery of peroxynitrite and peroxidase-induced nitration of biomolecules led to the initial reports of endogenous nitrated fatty acids. These species increase during ischemia reperfusion, but concentrations are often at or near the limits of detection. Here, we describe multiple methods for nitrated fatty acid synthesis, sample extraction from complex biological matrices, and a rigorous method of qualitative and quantitative detection of nitrated fatty acids by LC-MS. In addition, optimized instrument conditions and caveats regarding data interpretation are discussed. PMID:23200809

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

2012-01-01

297

Continuous flow nitration in miniaturized devices  

PubMed Central

Summary This review highlights the state of the art in the field of continuous flow nitration with miniaturized devices. Although nitration has been one of the oldest and most important unit reactions, the advent of miniaturized devices has paved the way for new opportunities to reconsider the conventional approach for exothermic and selectivity sensitive nitration reactions. Four different approaches to flow nitration with microreactors are presented herein and discussed in view of their advantages, limitations and applicability of the information towards scale-up. Selected recent patents that disclose scale-up methodologies for continuous flow nitration are also briefly reviewed. PMID:24605161

2014-01-01

298

HENC performance evaluation and plutonium calibration  

SciTech Connect

The authors have designed a high-efficiency neutron counter (HENC) to increase the plutonium content in 200-L waste drums. The counter uses totals neutron counting, coincidence counting, and multiplicity counting to determine the plutonium mass. The HENC was developed as part of a Cooperative Research and Development Agreement between the Department of Energy and Canberra Industries. This report presents the results of the detector modifications, the performance tests, the add-a-source calibration, and the plutonium calibration at Los Alamos National Laboratory (TA-35) in 1996.

Menlove, H.O.; Baca, J.; Pecos, J.M. [Los Alamos National Lab., NM (United States); Davidson, D.R.; McElroy, R.D.; Brochu, D.B. [Canberra Industries, Meriden, CT (United States)

1997-10-01

299

Plutonium Immobilization Can Loading Conceptual Design  

SciTech Connect

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

Kriikku, E.

1999-05-13

300

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

SciTech Connect

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

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

1993-06-01

301

Sorption/Desorption Interactions of Plutonium with Montmorillonite  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

302

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

SciTech Connect

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

Forsberg, C.W.

1995-06-29

303

Effects of the physical state of tropospheric ammonium-sulfate-nitrate particles on global aerosol direct radiative forcing  

Microsoft Academic Search

The effect of aqueous versus crystalline sulfate- nitrate-ammonium tropospheric particles on global aerosol direct radiative forcing is assessed. A global three- dimensional chemical transport model predicts sulfate, ni- trate, and ammonium aerosol mass. An aerosol thermody- namics model is called twice, once for the upper side (US) and once for lower side (LS) of the hysteresis loop of parti- cle

S. T. Martin; H.-M. Hung; R. J. Park; D. J. Jacob; R. J. D. Spurr; K. V. Chance; M. Chin

2003-01-01

304

Phase diagram of ammonium nitrate  

NASA Astrophysics Data System (ADS)

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

Dunuwille, M.; Yoo, C. S.

2014-05-01

305

Rapid determination of plutonium content on filters and smears using Alpha Liquid Scintillation  

SciTech Connect

This paper discusses a technique for rapidly determining plutonium content on filters and smears using Alpha Liquid Scintillation. Filter and smear samples will be analyzed daily for plutonium (Pu{sup 239}) content during projected waste retrieval operations at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory. daily monitoring will allow for trending of airborne and surface contamination. Alpha Liquid Scintillation (ALS) in conjunction with microwave digestion was investigated as a technique for rapid Pu analyses. Advantages offered by ALS are short turnaround time and field use with acceptable accuracy. A state-of-the-art Photon Electron Rejecting Alpha Liquid Scintillation (PERALS) Spectrometer utilizing pulse shape discrimination (PSD), and on oil filled photomultiplier tube counting chamber with 99.7% counting efficiency and 99.95% rejection of beta and gamma pulses, was used. Relatively clean filter samples could be directly counted in an all purpose scintillant, bis 2-ethylhexyl phosphoric acid (HDEHP), 4-biphenyl-6-phenylbenzoxazole (PBBO), toluene and naphthalene. Laboratory preparation of soil samples and smears with high inert solids content was accomplished by dissolution of the sample in nitric and hydrofluoric acids using a microwave digestion system in teflon pressure vessels. The Pu in the dissolved sample was extracted into tertiary amine nitrate and counted in a HDEHP or 1-nonyldecylamine sulfate (NDAS) containing extractive scintillant. This method is applicable to the determination of total plutonium in air filters, smears and soils. 9 refs., 8 figs., 5 tabs.

Shaw, P.G.

1989-01-01

306

Uranium plutonium oxide fuels. [LMFBR  

SciTech Connect

Uranium plutonium oxide is the principal fuel material for liquid metal fast breeder reactors (LMFBR's) throughout the world. Development of this material has been a reasonably straightforward evolution from the UO/sub 2/ used routinely in the light water reactor (LWR's); but, because of the lower neutron capture cross sections and much lower coolant pressures in the sodium cooled LMFBR's, the fuel is operated to much higher discharge exposures than that of a LWR. A typical LMFBR fuel assembly is shown. Depending on the required power output and the configuration of the reactor, some 70 to 400 such fuel assemblies are clustered to form the core. There is a wide variation in cross section and length of the assemblies where the increasing size reflects a chronological increase in plant size and power output as well as considerations of decreasing the net fuel cycle cost. Design and performance characteristics are described.

Cox, C.M.; Leggett, R.D.; Weber, E.T.

1981-01-01

307

Plutonium focus area: Technology summary  

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 approach, EM developed a management structure and principles that led to creation of specific focus areas. These organizations were designed to focus scientific and technical talent throughout DOE and the national scientific community on major environmental restoration and waste management problems facing DOE. The focus area approach provides the framework for inter-site 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), the Nuclear Materials Stabilization Task Group (NMSTG, EM-66) followed EM-50`s structure and chartered the Plutonium Focus Area (PFA). NMSTG`s charter to the PFA, described in detail later in this book, plays a major role in meeting the EM-66 commitments to the Defense Nuclear Facilities Safety Board (DNFSB). The PFA is a new program for FY96 and as such, the primary focus of revision 0 of this Technology Summary is an introduction to the Focus Area; its history, development, and management structure, including summaries of selected technologies being developed. Revision 1 to the Plutonium Focus Area Technology Summary is slated to include details on all technologies being developed, and is currently planned for release in August 1996. The following report outlines the scope and mission of the Office of Environmental Management, EM-60, and EM-66 organizations as related to the PFA organizational structure.

NONE

1996-03-01

308

Plutonium Mobility Through Vadose Zone Lysimeters: Influence of Oxidation State  

NASA Astrophysics Data System (ADS)

Understanding the processes controlling plutonium (Pu) mobility in the subsurface environment is important for estimating the amount of Pu waste that can be safely disposed in vadose zone burial sites. To study long-term Pu mobility, four 52-L lysimeters filled with sediment collected from the Savannah River Site near Aiken South Carolina were amended with well characterized solid Pu sources (Pu(III)-chloride, Pu(IV)-nitrate, Pu(IV)-oxalate, and Pu(VI)-nitrate and left exposed to natural precipitation for 2 to 11 years. Pu oxidation state distribution in the Pu(III) and Pu(IV) lysimeters sediments (a red clayey sediment, pH = 6.3) were similar, consisting of 0% Pu(III), >92% Pu(IV), 1% Pu(V), 1% Pu(VI), and the remainder was a Pu polymer. These three lysimeters also had near identical sediment Pu concentration profiles, where >95% of the Pu remained within 1.25 cm of the source after 11 years; moving at an overall rate of 0.9 cm/yr. As expected, Pu moved more rapidly through the Pu(VI) lysimeter, at an overall rate of 12.5 cm/yr. Solute transport modeling of the sediment Pu concentration profile data in the Pu(VI) lysimeter indicated that some transformation of Pu into a much less mobile form, presumably Pu(IV), had occurred during the course of the two year study. This modeling also supported previous laboratory measurements showing that Pu(V) or Pu(VI) reduction was five orders of magnitude faster than corresponding Pu(III) or Pu(IV) oxidation. The slow oxidation rate (1e-8 1/hr; half-life = 8,000 yr) was not discernable from the Pu(VI) lysimeter data that reflected only two years of transport but was readily discernable from the Pu(III) and Pu(IV) lysimeter data that reflected 11 yr of transport.

Kaplan, D.; Demirkanli, D. I.; Gumapas, L.; Powell, B. A.; Fjeld, R. A.; Molz, F. I.; Serkiz, S. M.

2005-12-01

309

International shipment of plutonium by air  

SciTech Connect

In support of the United States (US) Government`s decision to place excess plutonium oxide at the US Department of Energy`s (DOE) Hanford Site under International Atomic Energy Agency (IAEA) safeguards, the Department of State notified the Congress that a plutonium storage vault at the Plutonium Finishing Plant at the Hanford Site would be added to the eligible facilities list. As part of the preparations to transfer the plutonium oxide under IAEA safeguards, samples of the powder were taken from the inventory to be shipped to the IAEA headquarters in Vienna, Austria, for laboratory analysis. The analysis of these samples was of high priority, and the IAEA requested that the material be shipped by aircraft, the most expeditious method.

Mercado, J.E.; McGrogan, J.P.

1995-05-01

310

Plutonium Sphere Reflected by Reflected by Beryllium.  

National Technical Information Service (NTIS)

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

D. Loaiza, J. Hutchinson

2013-01-01

311

Carbonate Complexation of Plutonium(IV).  

National Technical Information Service (NTIS)

Plutonium(IV) carbonate complexes are expected to be of particular importance in typical groundwaters at the Yucca Mountain site of the candidate nuclear waste repository being studied by the Nevada Nuclear Waste Storage Investigations Project. The chemis...

D. E. Hobart, P. D. Palmer, T. W. Newton

1985-01-01

312

Plutonium finishing plant dangerous waste training plan  

SciTech Connect

This training plan describes general requirements, worker categories, and provides course descriptions for operation of the Plutonium Finish Plant (PFP) waste generation facilities, permitted treatment, storage and disposal (TSD) units, and the 90-Day Accumulation Areas.

ENTROP, G.E.

1999-05-24

313

Design and evaluation of plutonium electrorefining cells  

SciTech Connect

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

Not Available

1987-01-01

314

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

SciTech Connect

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

Rao, Linfeng; Tian, Guoxin

2008-12-10

315

Effects of nitrate on the stability of uranium in a bioreduced region of the subsurface  

SciTech Connect

The effects of nitrate on the stability of reduced, immobilized uranium were evaluated in field experiments at a U.S. Department of Energy site in Oak Ridge, TN. Nitrate (2.0 mM) was injected into a reduced region of the subsurface containing high levels of previously immobilized U(IV). The nitrate was reduced to nitrite, ammonium, and nitrogen gas; sulfide levels decreased; and Fe(II) levels increased then deceased. Uranium remobilization occurred concomitant with nitrite formation, suggesting nitrate-dependent, iron-accelerated oxidation of U(IV). Bromide tracer results indicated changes in subsurface flowpaths likely due to gas formation and/or precipitate. Desorption-adsorption of uranium by the iron-rich sediment impacted uranium mobilization and sequestration. After rereduction of the subsurface through ethanol additions, background groundwater containing high levels of nitrate was allowed to enter the reduced test zone. Aqueous uranium concentrations increased then decreased. Clone library analyses of sediment samples revealed the presence of denitrifying bacteria that can oxidize elemental sulfur, H{sub 2}S, Fe(II), and U(IV) (e.g., Thiobacillus spp.), and a decrease in relative abundance of bacteria that can reduce Fe(III) and sulfate. XANES analyses of sediment samples confirmed changes in uranium oxidation state. Addition of ethanol restored reduced conditions and triggered a short-term increase in Fe(II) and aqueous uranium, likely due to reductive dissolution of Fe(III) oxides and release of sorbed U(VI). After two months of intermittent ethanol addition, sulfide levels increased, and aqueous uranium concentrations gradually decreased to <0.1 {mu}M.

Wu, Weimin [Stanford University; Carley, Jack M [ORNL; Green, Stefan [Florida State University, Tallahassee; Luo, Jian [Georgia Institute of Technology; Kelly, Shelly D [Argonne National Laboratory (ANL); Van Nostrand, Joy [University of Oklahoma, Norman; Lowe, Kenneth Alan [ORNL; Mehlhorn, Tonia L [ORNL; Carroll, Sue L [ORNL; Boonchayanant, Dr. Benjaporn [Stanford University; Loeffler, Frank E [ORNL; Jardine, Philip M [ORNL; Criddle, Craig [ORNL

2010-06-01

316

Zirconia ceramics for excess weapons plutonium waste  

Microsoft Academic Search

We synthesized a zirconia (ZrO2)-based single-phase ceramic containing simulated excess weapons plutonium waste. ZrO2 has large solubility for other metallic oxides. More than 20 binary systems AxOy–ZrO2 have been reported in the literature, including PuO2, rare-earth oxides, and oxides of metals contained in weapons plutonium wastes. We show that significant amounts of gadolinium (neutron absorber) and yttrium (additional stabilizer of

W. L. Gong; W. Lutze; R. C. Ewing

2000-01-01

317

Plutonium-238 processing at Savannah River Plant  

SciTech Connect

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

Burney, G.A.

1983-01-01

318

Dangerous surplus. [Management of weapons plutonium  

Microsoft Academic Search

As a result of existing arms control reduction commitments, approximately 50 metric tons of weapon-grade plutonium is expected to become surplus in the United States--and a similar or larger amount in Russia--over the next 10 years. It is crucial that this surplus weapons plutonium be managed in a way that minimizes the danger that it will be re-used for weapons,

Holdren

2009-01-01

319

Explosive properties of reactor?grade plutonium  

Microsoft Academic Search

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

J. Carson Marka

1993-01-01

320

Extended testing of a modified 18B plutonium nitrate shipping container  

SciTech Connect

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

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

1980-01-01

321

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

NASA Astrophysics Data System (ADS)

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

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

2002-01-01

322

Guidelines for international plutonium management: Overview and implications  

SciTech Connect

In September, 1997, nine of the world`s plutonium-using countries agreed to a set of guidelines for international plutonium management, with acceptances to be submitted to the International Atomic Energy Agency on December 1. Following three years of discussion, the guidelines provide a unified package of accepted rules for the storage, handling, and transportation of civil plutonium as well as military plutonium that has been declared as no longer required for defense purposes. New requirements include a formal declaration of national plutonium strategies, which will recognize the environmental, economic, and proliferation concerns and the consequent importance of balancing plutonium supply and demand. Nations will also make annual declaration of their non-military stockpiles of unirradiated plutonium, together with estimates of the plutonium content in spent reactor fuel. These guidelines represent the first formally accepted recognition of the need for plutonium management of this scope and could thus provide a partial basis for future monitoring and policy regimes.

Bryson, M.C. [Los Alamos National Lab., NM (United States); Fitzgerald, C.P.; Kincaid, C. [Dept. of Energy, Washington, DC (United States)

1998-12-31

323

Thermodynamic quantities of surface formation of aqueous electrolyte solutions VIII. Aqueous solutions of sulfates salts.  

PubMed

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 of sulfate salts depends to some extent upon cations while that of alkali metal nitrate gives almost the same magnitude. In order to make comparison with salts of different valence types, we used the ratio of surface excess density to bulk concentration of a salt as an index of surface activity of the salt. It was shown that the surface activity of a salt largely dependent upon its valence type as well as its specific property of anion. PMID:18930247

Matubayasi, Norihiro; Tsuchihashi, Susumu; Yoshikawa, Ryuji

2009-01-15

324

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

SciTech Connect

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

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

1997-11-01

325

A novel derivative for the assessment of urinary and salivary nitrate using gas chromatography/mass spectrometry.  

PubMed

Previous gas chromatography/mass spectrometry (GC/MS) methods for determining nitrate in biological samples involve either hazardous chemicals or produce multiple isomers that can be difficult to quantitate. Modification of these methods, by the nitration of mesitylene instead of benzene and in the presence of trifluoroacetic anhydride rather than sulphuric acid, should enable simple isotopic quantitation for use in tracer studies, for example, in the measurement of nitric oxide production. Desiccated urine and saliva samples, in addition to aqueous labelled and unlabelled nitrate standards, were treated with trifluoroacetic anhydride and mesitylene at 70 degrees C for 1 h, cooled, then sequentially washed with deionised water and aqueous sodium bicarbonate. The solution of nitromesitylene in mesitylene was separated, dried and analysed by GC/MS. The full mass spectra exhibited abundant ions at m/z 165 and 166 corresponding to the unlabelled and labelled molecular species of nitromesitylene, respectively. Selected ion monitoring of these masses for a series of gravimetrically prepared standards indicated good agreement with isotopic enrichments in the range 0.0625-5 mole % excess, and at nitrate concentrations within the physiological range of 0.078-2 mmol/L. Derivatised samples were stable with respect to isotopic enrichments and nitrate concentrations at -20 degrees C for up to 21 days and exhibited excellent repeatability. Nitration of mesitylene proved to be a simple and rapid method for the measurement of isotope ratios in aqueous nitrates by GC/MS, which has applications in tracer studies and in concentration determinations by isotope dilution techniques for nitric oxide production. PMID:19039799

Jackson, Sarah J; Siervo, Mario; Persson, Emma; McKenna, Louise M; Bluck, Leslie J C

2008-12-01

326

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

Microsoft Academic Search

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

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

2004-01-01

327

Fast photolysis of carbonyl nitrates from isoprene  

NASA Astrophysics Data System (ADS)

We show that photolysis is, by far, the major atmospheric sink of isoprene-derived carbonyl nitrates. Empirical evidence from published laboratory studies on the absorption cross sections and photolysis rates of ?-nitrooxy ketones suggests that the presence of the nitrate group (i) greatly enhances the absorption cross sections, and (ii) facilitates dissociation to a point that the photolysis quantum yield is close to unity, with O-NO2 dissociation as the likely major channel. On this basis, we provide new recommendations for estimating the cross sections and photolysis rates of carbonyl nitrates. The newly estimated photorates are validated using a chemical box model against measured temporal profiles of carbonyl nitrates in an isoprene oxidation experiment by Paulot et al. (2009). The comparisons for ethanal nitrate and for the sum of methacrolein- and methylvinylketone nitrates strongly supports our assumptions of large cross section enhancements and a near-unit quantum yield for these compounds. These findings have significant atmospheric implications, as carbonyl nitrates constitute an important component of the total organic nitrate pool over vegetated areas: the photorates of key carbonyl nitrates from isoprene are estimated to be typically between ~3 and 20 times higher than their sink due to reaction with OH in relevant atmospheric conditions. Moreover, since the reaction is expected to release NO2, photolysis is especially effective in depleting the total organic nitrate pool.

Müller, Jean-Francois; Peeters, Jozef; Stavrakou, Trisevgeni

2014-05-01

328

Nitrate deposition and impact of Adirondack streams  

SciTech Connect

Acidic deposition has a great impact on water chemistry and fish populations in the Adirondack region. Although the Clean Air Act Amendments of 1990 have resulted in some reductions of sulfur deposition, nitrate deposition has not yet been well controlled, and continues to impact aquatic resources. As part of the USEPA funded Episodic Response Project, four Adirondack headwater streams were intensively monitored over an 18 month period. Atmospheric deposition was also monitored at a centrally located station. The quantity of nitrate being deposited on the study watersheds was calculated based on monthly net deposition data, which ranged from 0.6 kg/ha/month to 3.6 kg/ha/month. These data were then compared to the monthly export of nitrate from the watershed in these streams. Nitrate concentrations were highest in the stream water during the spring snowmelt period prior to the time when forest vegetation actively utilizes nitrate. On an annual basis, the amount of nitrate that left the watershed via stream water was approximately equal to the amount that fell as nitrate deposition. These data are important in documenting the impact that nitrate has in acidifying Adirondack streams during the spring, which coincides with brook trout hatching. Control programs for nitrous oxide emissions are presently aimed at reducing ozone levels during the May--September period. These emissions control programs need to be expanded to also reduce nitrate deposition in the sensitive Adirondack region during the water and spring periods when nitrate deposition has its greatest impact on aquatic resources.

Simonin, H.A. [New York State Dept. of Environmental Conservation, Rome, NY (United States). Rome Field Station; Kretser, W. [New York State Dept. of Environmental Conservation, Ray Brook, NY (United States). Adirondack Lakes Survey Corp.

1995-12-31

329

Plutonium Finishing Plant safety evaluation report  

SciTech Connect

The Plutonium Finishing Plant (PFP) previously known as the Plutonium Process and Storage Facility, or Z-Plant, was built and put into operation in 1949. Since 1949 PFP has been used for various processing missions, including plutonium purification, oxide production, metal production, parts fabrication, plutonium recovery, and the recovery of americium (Am-241). The PFP has also been used for receipt and large scale storage of plutonium scrap and product materials. The PFP Final Safety Analysis Report (FSAR) was prepared by WHC to document the hazards associated with the facility, present safety analyses of potential accident scenarios, and demonstrate the adequacy of safety class structures, systems, and components (SSCs) and operational safety requirements (OSRs) necessary to eliminate, control, or mitigate the identified hazards. Documented in this Safety Evaluation Report (SER) is DOE`s independent review and evaluation of the PFP FSAR and the basis for approval of the PFP FSAR. The evaluation is presented in a format that parallels the format of the PFP FSAR. As an aid to the reactor, a list of acronyms has been included at the beginning of this report. The DOE review concluded that the risks associated with conducting plutonium handling, processing, and storage operations within PFP facilities, as described in the PFP FSAR, are acceptable, since the accident safety analyses associated with these activities meet the WHC risk acceptance guidelines and DOE safety goals in SEN-35-91.

Not Available

1995-01-01

330

A vision for environmentally conscious plutonium processing  

SciTech Connect

Regardless of individual technical and political opinions about the uses of plutonium, it is virtually certain that plutonium processing will continue on a significant global scale for many decades for the purposes of national defense, nuclear power and remediation. An unavoidable aspect of plutonium processing is that radioactive contaminated gas, liquid, and solid streams are generated. These streams need to be handled in a manner that is not only in full compliance with today`s laws,but also will be considered environmentally and economically responsible now and in the future. In this regard, it is indeed ironic that the multibillion dollar and multidecade radioactive cleanup mortgage that the US Department of Energy (and its Russian counterpart) now owns resulted from waste management practices that were at the time in full legal compliance. The theme of this paper is that recent dramatic advances in actinide science and technology now make it possible to drastically minimize or even eliminate the problematic waste streams of traditional plutonium processing operations. Advanced technology thereby provides the means to avoid passing on to our children and grandchildren significant environmental and economic legacies that traditional processing inevitably produces. This paper will describe such a vision for plutonium processing that could be implemented fully within five years at a facility such as the Los Alamos Plutonium Facility (TA55). As a significant bonus, even on this short time scale, the initial technology investment is handsomely returned in avoided waste management costs.

Avens, L.R.; Eller, P.G.; Christensen, D.C. [Los Alamos National Lab., NM (United States). Nuclear Materials Technology Div.; Miller, W.L. [Univ. of Florida, Gainesville, FL (United States). Dept. of Environmental Engineering Sciences

1998-12-31

331

Continuous process for the production of powdered uranium dioxide from uranyl nitrate  

SciTech Connect

A method is described of producing uranium dioxide powder for the fabrication of nuclear fuel from acidic solutions containing uranyl nitrate, comprising the sequence of steps of: (a) continuously reacting an acidic aqueous solution of uranyl nitrate with ammonium hydroxide added in less than stoichiometric amount for complete uranium precipitation, neutralizing any free acid and precipitating a portion of the uranium content of the solution as ammonium uranate solids; (b) continuously aging the product resulting from reacting the uranyl nitrate of the solution with less than a stoichiometric amount of ammonium hydroxide, including the precipitated ammonium uranate solids while maintaining the solids substantially suspended in the medium of the aqueous solution; (c) thereafter continuously reacting the aged product comprising uranyl nitrate and precipitated ammonium uranate with additional added ammonium hydroxide in amount at least sufficient to complete the precipitation of the uranium of the solution as ammonium uranate solids; and (e) calcining the dewatered ammonium uranate solids in a reducing atmosphere and thereby converting the ammonium uranate solids in a reducing atmosphere and thereby converting the ammonium uranate to uranium dioxide powder.

Divins, L.A.; Runion, H.L.

1987-04-07

332

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

Microsoft Academic Search

The Secretary of Energy requested the National Academy of Sciences (NAS) Committee on International Security and Arms Control to evaluate disposition options for weapons-grade plutonium. The Idaho National Engineering Laboratory (INEL) offered to assist the NAS in this evaluation by investigating the technical aspects of the disposition options and their capability for achieving plutonium annihilation levels greater than 90%. This

D. A. Brownson; D. J. Hanson; H. S. Blackman

1993-01-01

333

Recent trends of plutonium fallout observed in Japan: plutonium as a proxy for desertification.  

PubMed

Plutonium in monthly deposition samples collected in Tsukuba (the Meteorological Research Institute), Japan from 1990 to end of 2001 is reported, together with monthly plutonium deposition in Nagasaki and Yonaguni in 2000. The annual deposition of (239,240)Pu during the period from 1990 to 2001 shows no systematic interannual variation. However, monthly (239,240)Pu depositions show a typical seasonal variation with a maximum in spring season (March to April), which corresponds to seasonal cycle of soil dusts originating from the East Asian arid area. Plutonium isotopic ratios in the deposition samples suggest that significant amounts of the recent (239,240)Pu deposition observed in Japan are attributed to the resuspension of plutonium-bearing surface soil particles; resuspended plutonium originates from the East Asian arid areas. The recent increased tendency of (239,240)Pu content in residues in deposition samples may reflect desertification in the East Asian continent. PMID:12729272

Hirose, Katsumi; Igarashi, Yasuhito; Aoyama, Michio; Kim, C K; Kim, C S; Chang, B W

2003-04-01

334

Method for Plutonium-Gallium Separation by Anodic Dissolution of a Solid Plutonium-Gallium Alloy  

SciTech Connect

Purified plutonium and gallium are efficiently recovered from a solid plutonium-gallium (Pu-Ga) alloy by using an electrorefining process. The solid Pu-Ga alloy is the cell anode, preferably placed in a moving basket within the electrolyte. As the surface of the Pu-Ga anode is depleted in plutonium by the electrotransport of the plutonium to a cathode, the temperature of the electrolyte is sufficient to liquify the surface, preferably at about 500 C, resulting in a liquid anode layer substantially comprised of gallium. The gallium drips from the liquified surface and is collected below the anode within the electrochemical cell. The transported plutonium is collected on the cathode surface and is recovered.

Miller, William E.; Tomczuk, Zygmunt

1998-12-08

335

Nitrite/nitrate detection in serum based on dual-plate generator-collector currents in a microtrench.  

PubMed

A dual-electrode sensor is developed for rapid detection of nitrite/nitrate at micromolar levels in phosphate buffer media and in dilute horse serum without additional sample pre-treatment. A generator-collector configuration is employed so that on one electrode nitrate is reduced to nitrite and on the second electrode nitrite is oxidised back to nitrate. The resulting redox cycle gives rise to a specific and enhanced current signal which is exploited for sensitive and reliable measurement of nitrite/nitrate in the presence of oxygen. The electrode design is based on a dual-plate microtrench (approximately 15µm inter-electrode gap) fabricated from gold-coated glass and with a nano-silver catalyst for the reduction of nitrate. Fine tuning of the phosphate buffer pH is crucial for maximising collector current signals whilst minimising unwanted gold surface oxidation. A limit of detection of 24?M nitrate and a linear concentration range of 200-1400?M is reported for the microtrench sensor in phosphate buffer and dilute horse serum. Relative standard deviations for repeat measurements were in the range 1.8-6.9% (n=3) indicating good repeatability in both aqueous and biological media. Preliminary method validation against the standard chemiluminescence method used in medical laboratories is reported for nitrate analysis in serum. PMID:25281097

Gross, Andrew J; Holmes, Stephanie; Dale, Sara E C; Smallwood, Miranda J; Green, Stephen J; Peter Winlove, C; Benjamin, Nigel; Winyard, Paul G; Marken, Frank

2015-01-01

336

Preparation of hydrophobic nano-silver colloid and aqueous nano-silver colloid by phase transfer  

Microsoft Academic Search

A novel and facile method to prepare hydrophobic nano-silver colloid and aqueous coordinate was proposed. Chemical reduction of silver nitrate in a tributyl phosphate (TBP) solution containing polyvinylpyrrolidone (PVP) was conducted and stable hydrophobic nano-silver\\/TBP\\/PVP colloids were obtained. Adopting a phase transfer process, the as-prepared colloids can be diverted into an aqueous system to obtain hydrophilic nano-silver colloids. The resultant

Shanshan Wei; Xiangyang Xu; Yuejun Liu; Junming Yang

2011-01-01

337

Pollution of drinking water with nitrate  

Microsoft Academic Search

The main sources of nitrate in man are food and drinking water. The legislature in West Germany intends to lower the permitted level of nitrate in drinking water from the present 90 mg\\/l to 50 mg\\/l in 1982. The European Community has issued a directive that recommends a level of only 25 mg\\/l, and for babies 10 mg\\/l nitrate should

B. Cabel; R. Kozicki; U. Lahl; A. Podbielshi; B. Stachel; S. Struss

1982-01-01

338

Mammalian Nitrate Biosynthesis: Incorporation of 15NH3 into Nitrate is Enhanced by Endotoxin Treatment  

NASA Astrophysics Data System (ADS)

Incorporation of an oral dose of [15N]ammonium acetate into urinary [15N]nitrate has been demonstrated in the rat. Investigation of the regulation of nitrate synthesis has shown that Escherichia coli lipopolysaccharide potently stimulates urinary nitrate excretion (9-fold increase). It was further shown that the enhanced rate of nitrate excretion by lipopolysaccharide was due not to a reduction in nitrate metabolic loss but rather to an increased rate of synthesis. This conclusion was based on finding a proportionally increased incorporation of [15N]ammonium into nitrate nitrogen with lipopolysaccharide treatment. Nitrate biosynthesis was also increased by intraperitoneal injection of carrageenan and subcutaneous injection of turpentine. It is proposed that the pathway of nitrate biosynthesis may be the result of oxidation of reduced nitrogen compounds by oxygen radicals generated by an activated reticuloendothelial system.

Wagner, David A.; Young, Vernon R.; Tannenbaum, Steven R.

1983-07-01

339

Trend Analyses of Nitrate in Danish Groundwater  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

340

Free amino acids, nitrate, and nitrate reductase in nitrogen fixation by soybean nodules  

E-print Network

FREE AMINO ACIDS, NITRATE, AND NITRATE REDUCTASE IN NITROGEN FIXATION BY SOYBEAN NODULES A Thesis by PAUL CLAYTON MADTES, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1978 Major Subject: Biophysics FREE AMINO ACIDS, NITRATE, AND NITRATE REDUCTASE IN NITROGEN FIXATION BY SOYBEAN NPDULES A Thesis by PAUL CLAYTON MADTES, JR. Approved as to style and content by: g jap (Chairman...

Madtes, Paul Clayton

2012-06-07

341

Effect of nitrate supply and mycorrhizal inoculation on characteristics of tobacco root plasma membrane vesicles.  

PubMed

Plant plasma membrane (pm) vesicles from mycorrhizal tobacco (Nicotiana tabacum cv. Samsun) roots were isolated with negligible fungal contamination by the aqueous two-phase partitioning technique as proven by fatty acid analysis. Palmitvaccenic acid became apparent as an appropriate indicator for fungal membranes in root pm preparations. The pm vesicles had a low specific activity of the vanadate-sensitive ATPase and probably originated from non-infected root cells. In a phosphate-limited tobacco culture system, root colonisation by the vesicular arbuscular mycorrhizal fungus, Glomus mosseae, is inhibited by external nitrate in a dose-dependent way. However, detrimental high concentrations of 25 mM nitrate lead to the highest colonisation rate observed, indicating that the defence system of the plant is impaired. Nitric oxide formation by the pm-bound nitrite:NO reductase increased in parallel with external nitrate supply in mycorrhizal roots in comparison to the control plants, but decreased under excess nitrate. Mycorrhizal pm vesicles had roughly a twofold higher specific activity as the non-infected control plants when supplied with 10-15 mM nitrate. PMID:19937342

Moche, Martin; Stremlau, Stefanie; Hecht, Lars; Göbel, Cornelia; Feussner, Ivo; Stöhr, Christine

2010-01-01

342

Safety in the Chemical Laboratory: Nitric Acid, Nitrates, and Nitro Compounds.  

ERIC Educational Resources Information Center

Discussed are the potential hazards associated with nitric acid, inorganic and organic nitrate salts, alkyl nitrates, acyl nitrates, aliphatic nitro compounds, aromatic nitro compounds, and nitration reactions. (CW)

Bretherick, Leslie

1989-01-01

343

Synthesis and sintering behavior of La 0.8Sr 0.2CrO 3 by a glycine nitrate process  

Microsoft Academic Search

La0.8Sr0.2CrO3 powder was synthesized by a glycine nitrate process from an aqueous solution of lanthanum, strontium, and chromium nitrates, and glycine. The apparent density, size and morphology of the La0.8Sr0.2CrO3 powder depended on the glycine-to-nitrate ratio. However, the pH value of the precursor solution had no significant effect on these properties. It was found that a single-phase perovskite, La0.8Sr0.2CrO3, was

Elizabeth Thomas; Da Hae Lee; Mi Young Yoon; Sheryl. H Ehrman; Hae Jin Hwang

2011-01-01

344

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

Microsoft Academic Search

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

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

2007-01-01

345

Nitrate, nitrite, and volatile nitrosamines in pickled fish prepared with addition of nitrate  

Microsoft Academic Search

Zusammenfassung Marinierter Hering, hergestellt mit Nitrat als Zusatzstoff, wurde auf Gehalt von Nitrat, Nitrit und flüchtige Nitrosamine untersucht. Der Gehalt von Nitrat war entweder ungefähr 10 mg\\/kg oder variierte von 35 bis 565 mg\\/kg. Der Gehalt von Nitrit war nicht meßbar oder niedrig (2 mg\\/kg). Mehrere Proben enthielten N-Nitrosodimethylamin bis 2.2 µg\\/ kg.

Erling Pedersen; Inge Meyland

1981-01-01

346

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2012 CFR

...70 percent of ammonium nitrate and a maximum of 0.4 percent combustible material; (2) Ammonium nitrate with calcium carbonate and/or dolomite, containing more than 80 percent but less than 90 percent of ammonium nitrate and a maximum...

2012-10-01

347

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2013 CFR

...70 percent of ammonium nitrate and a maximum of 0.4 percent combustible material; (2) Ammonium nitrate with calcium carbonate and/or dolomite, containing more than 80 percent but less than 90 percent of ammonium nitrate and a maximum...

2013-10-01

348

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2011 CFR

...70 percent of ammonium nitrate and a maximum of 0.4 percent combustible material; (2) Ammonium nitrate with calcium carbonate and/or dolomite, containing more than 80 percent but less than 90 percent of ammonium nitrate and a maximum...

2011-10-01

349

The NreA protein functions as a nitrate receptor in the staphylococcal nitrate regulation system.  

PubMed

Staphylococci are able to use nitrate as an alternative electron acceptor during anaerobic respiration. The regulation of energy metabolism is dependent on the presence of oxygen and nitrate. Under anaerobic conditions, staphylococci employ the nitrate regulatory element (Nre) for transcriptional activation of genes involved in reduction and transport of nitrate and nitrite. Of the three proteins that constitute the Nre system, NreB has been characterized as an oxygen sensor kinase and NreC has been characterized as its cognate response regulator. Here, we present structural and functional data that establish NreA as a new type of nitrate receptor. The structure of NreA with bound nitrate was solved at 2.35Å resolution, revealing a GAF domain fold. Isothermal titration calorimetry experiments showed that NreA binds nitrate with low micromolar affinity (KD=22?M). Two crystal forms for NreA were obtained, with either bound nitrate or iodide. While the binding site is hydrophobic, two helix dipoles and polar interactions contribute to specific binding of the ions. The expression of nitrate reductase (NarGHI) was examined using a narG-lip (lipase) reporter gene assay in vivo. Expression was regulated by the presence of NreA and nitrate. Structure-guided mutations of NreA reduced its nitrate binding affinity and also affected the gene expression, thus providing support for the function of NreA as a nitrate receptor. PMID:24389349

Niemann, Volker; Koch-Singenstreu, Mareike; Neu, Ancilla; Nilkens, Stephanie; Götz, Friedrich; Unden, Gottfried; Stehle, Thilo

2014-04-01

350

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

PubMed

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

Thadani, Udho

2014-08-01

351

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

EPA Science Inventory

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

352

Nitrite and Nitrate in Cancer  

Microsoft Academic Search

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

David M. Klurfeld

353

Preserving Plutonium-244 as a National Asset  

SciTech Connect

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

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

2011-01-01

354

Effect of compositional variation in plutonium on process shielding design  

SciTech Connect

Radiation dose rate from plutonium with high {sup 239}Pu content varies with initial nuclidic content, radioactive decay time, and impurity elemental content. The two idealized states of old plutonium and clean plutonium, whose initial compositions are given, provide approximate upper and lower bounds on dose rate variation. Whole-body dose rates were calculated for the two composition states, using unshielded and shielded plutonium spheres of varying density. The dose rates from these variable density spheres are similar to those from expanded plutonium configurations encountered during processing. The dose location of 40 cm from the sphere center is representative of operator standoff for direct handling of plutonium inside a glove box. The results have shielding implications for glove boxes with only structurally inherent shielding, especially for processing of old plutonium in an expanded configuration. Further reduction in total dose rate by using lead to reduce photon dose rate is shown for two density cases representing compact and expanded plutonium configurations.

Brown, T.H.

1997-11-01

355

Studies on the reverse osmosis treatment of uranyl nitrate solution  

SciTech Connect

The aqueous effluent generated in uranium processing, particularly in the nuclear fuel fabrication step, contains mainly uranium nitrate. This requires treatment before discharge into the environment to meet stringent standards. This paper presents the performance of cellulose acetate membranes with regard to rejection of uranium under reverse osmotic conditions for feed concentrations up to 200 mg/l of uranium, which corresponds to the levels normally prevalent in the effluents. The use of additives like the disodium salt of ethylenediaminetetraacetic acid and sodium sulfate for the improvement of reverse osmosis performance of the above membranes was also investigated. In the light of the experimental results, the suitability of reverse osmosis for the decontamination of uranium effluents is discussed.

Prabhakar, S.; Panicker, S.T.; Misra, B.M.; Ramani, P.S. (Bhabha Atomic Research Centre, Bombay (India))

1992-03-01

356

The plutonium-oxygen phase diagram  

SciTech Connect

Identification of products formed by the reaction of plutonium metal with liquid water at 23{degree}C indicates that the plutonium-oxygen phase diagram is similar to the cerium-oxygen and praseodymium-oxygen diagrams. Quantitative measurements of H{sub 2} formation and analytical data suggest that a sequence of hydrolysis reactions produces oxide hydrides of trivalent plutonium, Pu{sub 2}O{sub 3}, mixed-valent oxides and PuO{sub 2}. The intermediate oxides are the n {equals} 7, 9, 10 and 12 members of the Pu{sub n}O{sub 2n{minus}2} homologous series. Properties of the residue formed by thermal decomposition of the initial hydrolysis product, plutonium monoxide monhydride (PuOH), are consistent with the formation of metastable plutonium monoxide. Crystal-chemical, thermodynamic, and kinetic factors are evaluated, but definitive assignment of the equilibrium Pu-O diagram is not possible. 22 refs., 6 figs., 1 tab.

Haschke, J.M.

1990-01-01

357

MCNP5 CALCULATIONS REPLICATING ARH-600 NITRATE DATA  

SciTech Connect

This report serves to extend the previous document: 'MCNP Calculations Replicating ARH-600 Data' by replicating the nitrate curves found in ARH-600. This report includes the MCNP models used, the calculated critical dimension for each analyzed parameter set, and the resulting data libraries for use with the CritView code. As with the ARH-600 data, this report is not meant to replace the analysis of the fissile systems by qualified criticality personnel. The M CNP data is presented without accounting for the statistical uncertainty (although this is typically less than 0.001) or bias and, as such, the application of a reasonable safety margin is required. The data that follows pertains to the uranyl nitrate and plutonium nitrate spheres, infinite cylinders, and infinite slabs of varying isotopic composition, reflector thickness, and molarity. Each of the cases was modeled in MCNP (version 5.1.40), using the ENDF/B-VI cross section set. Given a molarity, isotopic composition, and reflector thickness, the fissile concentration and diameter (or thicknesses in the case of the slab geometries) were varied. The diameter for which k-effective equals 1.00 for a given concentration could then be calculated and graphed. These graphs are included in this report. The pages that follow describe the regions modeled, formulas for calculating the various parameters, a list of cross-sections used in the calculations, a description of the automation routine and data, and finally the data output. The data of most interest are the critical dimensions of the various systems analyzed. This is presented graphically, and in table format, in Appendix B. Appendix C provides a text listing of the same data in a format that is compatible with the CritView code. Appendices D and E provide listing of example Template files and MCNP input files (these are discussed further in Section 4). Appendix F is a complete listing of all of the output data (i.e., all of the analyzed dimensions and the resulting k{sub eff} values).

FINFROCK SH

2011-10-25

358

Occurrence of foliar nitrate reductase activity not induced by nitrate in symbiotic nitrogen-fed black alder (Alnus glutinosa)  

E-print Network

Occurrence of foliar nitrate reductase activity not induced by nitrate in symbiotic nitrogen-axenic conditions and supplied with nitrate or nitrate-free nutrient solution. The objectives were to: 1) evaluate the effect of nitrogen source and plant age on leaf nitrate reductase (NR) activity measured in vivo; 2

Paris-Sud XI, Université de

359

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

PubMed

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

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

2014-01-01

360

Nitrate Uptake, Nitrate Reductase Distribution and their Relation to Proton Release in Five Nodulated Grain Legumes  

PubMed Central

Nitrate uptake, nitrate reductase activity (NRA) and net proton release were compared in five grain legumes grown at 0·2 and 2 mm nitrate in nutrient solution. Nitrate treatments, imposed on 22?d?old, fully nodulated plants, lasted for 21 d. Increasing nitrate supply did not significantly influence the growth of any of the species during the treatment, but yellow lupin (Lupinus luteus) had a higher growth rate than the other species examined. At 0·2 mm nitrate supply, nitrate uptake rates ranged from 0·6 to 1·5 mg N g–1 d–1 in the order: yellow lupin > field pea (Pisum sativum) > chickpea (Cicer arietinum) > narrow?leafed lupin (L. angustifolius) > white lupin (L. albus). At 2 mm nitrate supply, nitrate uptake ranged from 1·7 to 8·2 mg N g–1 d–1 in the order: field pea > chickpea > white lupin > yellow lupin > narrow?leafed lupin. Nitrate reductase activity increased with increased nitrate supply, with the majority of NRA being present in shoots. Field pea and chickpea had much higher shoot NRA than the three lupin species. When 0·2 mm nitrate was supplied, narrow?leafed lupin released the most H+ per unit root biomass per day, followed by yellow lupin, white lupin, field pea and chickpea. At 2 mm nitrate, narrow?leafed lupin and yellow lupin showed net proton release, whereas the other species, especially field pea, showed net OH– release. Irrespective of legume species and nitrate supply, proton release was negatively correlated with nitrate uptake and NRA in shoots, but not with NRA in roots. PMID:12234143

FAN, X. H.; TANG, C.; RENGEL, Z.

2002-01-01

361

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

NASA Astrophysics Data System (ADS)

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

Doudrick, Kyle

362

Photolytic destruction of oxalate in aqueous mixed waste  

SciTech Connect

In aqueous plutonium processing, residual oxalic acid can be destroyed (oxalate kill) by UV light with hydrogen peroxide (H{sub 2}O{sub 2}) in 1 M HCl solutions. By controlling the amount of H{sub 2}O{sub 2}, the oxalate kill process will not affect the chloride concentration. In nitric acid solutions, UV light alone can destroy the oxalic acid. However, with H{sub 2}O{sub 2}, the rate of destruction is faster. After the destruction of oxalic acid, the acidic solutions may be reusable without further purification process.

Wang, F.T.; Lum, B.Y.

1995-03-01

363

Emulsion explosives containing high concentrations of calcium nitrate  

SciTech Connect

A water-in-oil emulsion blasting agent is described having a discontinuous aqueous oxidizer salt solution phase which contains a calcium nitrate (CN) to ammonium nitrate (AN) weight ratio of 1.5 or greater, a continuous oil or water-immiscible liquid organic phase, an emulsifier, and, optionally, a density reducing agent. It is found that emulsion slurry blasting agents containing this relatively high amount of CN to AN have properties that conventional emulsion slurry explosives, those containing more AN than CN or solely AN, do not. Specifically, one property is that the high-CN emulsion blasting agents of the present composition can have much smaller critical diameters but yet pass the US DOT Blasting Agent tests. This result will be shown in the examples that follow. Thus, if AN is present as the principal oxidizer salt, emulsion explosives that have small critical diameters, and even those with relatively large critical diameters, generally are too sensitive to pass the Blasting Agent tests. If CN is the principal oxidizer, the emulsion blasting agents are less sensitive and more likely to pass the tests. This effect of CN has commercial significance. 10 claims.

Jessop, H.A.; Funk, A.G.

1982-10-26

364

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

SciTech Connect

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

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

1989-01-01

365

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

Code of Federal Regulations, 2013 CFR

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2013-01-01

366

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

Code of Federal Regulations, 2010 CFR

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2010-01-01

367

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

Code of Federal Regulations, 2011 CFR

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2011-01-01

368

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

Code of Federal Regulations, 2010 CFR

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2010-01-01

369

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2014-01-01

370

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

Code of Federal Regulations, 2013 CFR

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2013-01-01

371

10 CFR 140.108 - Appendix H-Form of indemnity agreement with licensees possessing plutonium for use in plutonium...  

Code of Federal Regulations, 2012 CFR

...licensees possessing plutonium for use in plutonium processing and fuel fabrication plants and furnishing proof of financial...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2012-01-01

372

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2014-01-01

373

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

Code of Federal Regulations, 2012 CFR

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2012-01-01

374

10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...  

Code of Federal Regulations, 2011 CFR

...licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies...the agreement or is received at the plant for use or processing in the plant but which is, in fact, for any...

2011-01-01

375

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

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

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

376

Plutonium in surface soil in the Hanford plant environs  

Microsoft Academic Search

Analyses for plutonium in air, water, and foodstuffs have long been part ; of the routine surveillance program at Hanford. In addition, the ground and ; other surfaces have been surveyed for plutonium where there was possible ; deposition from stack emissions, waste spills, etc., using direct instrument ; measurements. Detectable plutonium deposition from the few such incidents has ;

J. P. Corley; D. M. Robertson; F. P. Brauer

1972-01-01

377

Storage MOX: A Third Way for Plutonium Disposal?  

Microsoft Academic Search

By 2010, the UK could have 110 tons of separated civilian plutonium and Russia up to 150 tons of excess weapons and civil plutonium. Neither country has enough LWR capacity for disposal in MOX fuel. Plutonium disposal via MOX fuel is also difficult for some other countries. Combined disposal with HLW may be infeasible after reprocessing ends because the reprocessing

J. Kang; F. N. von Hippel; A. MacFarlane; R. Nelson

2002-01-01

378

The behaviour of plutonium in the Pacific Ocean  

Microsoft Academic Search

The Pacific Ocean is a major repository of plutonium released from atmospheric tests of nuclear weapons. Both global fallout from plutonium released to the stratosphere as well as close-in fallout from the troposphere contributed to the present levels of plutonium in seawater and sediment of the Pacific Ocean. The paper provides an overview of the state of knowledge of the

Hugh D. Livingston; Pavel P. Povinec; Toshimichi Ito; Orihiko Togawa

2001-01-01

379

Proceedings of the Plutonium Futures—The Science 2006 Conference  

Microsoft Academic Search

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

Michael J. Fluss; David E. Hobart; Patrick G. Allen; Gordon D. Jarvinen

2007-01-01

380

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

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

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

381

THE ROLE OF PLUTONIUM IN THE BRITISH NUCLEAR POWER PROGRAMME  

Microsoft Academic Search

There are two principal incentives for the utilization of plutonium in ; reactors as part of the British Nuclear Power Programme. Plutonium will become ; available in increasing amounts from the natural uranium reactors, and ; assessments indicate that fast reactors burning plutonium may produce power more ; cheaply than any other reactor systems so far envisaged. The nuclear ;

Kronberger

1963-01-01

382

Electrochemical investigation into the mechanism of plutonium reduction in electrorefining  

SciTech Connect

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 reduction of the plutonium ions at a tungsten cathode to pure plutonium metal. Purification of the plutonium metal from impurities is based on the difference in free energies of formation between the various metallic impurities associated with plutonium. To obtain a better understanding of the overall electrorefining process and its inefficiencies, an electrochemical investigation into the mechanism for plutonium reduction in a typical electrorefining environment was undertaken. Cyclic voltammetry was selected as the method for determining the electrode mechanism for plutonium reduction at tungsten electrodes. In addition to the standard electrorefining melt (equimolar NaCl-KCl), additional melts that were being investigated in our solvent anode work were also investigated. With insight gained from this investigation, it was hoped that a better selection of electrorefining operating parameters could be obtained.

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

1987-01-01

383

Preparation of a glovebox for casting enriched plutonium.  

SciTech Connect

Objectives: Prepare existing glovebox for casting, heat treating and storing enriched plutonium, Upgrade seismic systems to reduce dispersion hazard, Upgrade atmospheric systems to reduce oxidation of plutonium, Upgrade vacuum system to prevent oxidation, InstalI/upgrade induction heating systems to melt plutonium and heat mold

Ronquillo, R. D. (Richard D.); Trujillo, C. M. (Chris M.); Trujillo, C. C. (Claudette C.)

2002-01-01

384

Nitrate Monitoring Biosensor System for Aquatic Environment  

Microsoft Academic Search

A microbial biosensor system was developed for nitrate monitoring. The system was constructed with an immobilized microorganism (Paracoccus dinitrificans IAM 12479), a Clark-type oxygen electrode, a micro-tube pump, and a recorder. The method was based on the determination of the oxygen consumption by the microorganism with the electrode in presence of nitrate. Optimum conditions for the sensor system was established

Hideaki Endo; Yasushi Nakazawa; Yoshiyuki Nagano; Huifeng Ren; Tetsuhito Hayashi

385

PARAMAGNETIC RESONANCE OF TERBIUM IN NITRATE  

Microsoft Academic Search

The paramagnetic resonance spectrum of Tb\\/sup 3+\\/ ion was observed in ; lanthanum nitrate monocrystal containing 0.1% terbium nitrate. The spectrum ; consisted of a single electron transition spallated into four lines corresponding ; to Tb¹⁵⁹ nuclear spin 3\\/4. Measurements were made at 13 K and 8970 and ; 9870 mc. (R.V.J.);

T. I. Sanadze; M. Kolach; G. A. Tsintsadze

1957-01-01

386

COMPARTMENTAL MODEL OF NITRATE RETENTION IN STREAMS  

EPA Science Inventory

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

387

Nitric oxide, oxidants, and protein tyrosine nitration  

Microsoft Academic Search

The occurrence of protein tyrosine nitration under disease conditions is now firmly established and represents a shift from the signal transducing physiological actions of NO to oxidative and potentially pathogenic pathways. Tyrosine nitration is mediated by reactive nitrogen species such as peroxynitrite anion (ONOO-) and nitrogen dioxide (NO2), formed as secondary products of NO metabolism in the presence of oxidants

Rafael Radi

2004-01-01

388

Nitrates and Prussic Acid in Forages  

E-print Network

When nitrates and prussic acid accumulate in forage, the feed may not be safe for livestock consumption. Learn the symptoms of nitrate and prussic acid poisoning and which plants are most likely to pose a risk to livestock. Also learn sampling...

Provin, Tony; Pitt, John L.

2003-01-06

389

Excess plutonium disposition: The deep borehole option  

SciTech Connect

This report reviews the current status of technologies required for the disposition of plutonium in Very Deep Holes (VDH). It is in response to a recent National Academy of Sciences (NAS) report which addressed the management of excess weapons plutonium and recommended three approaches to the ultimate disposition of excess plutonium: (1) fabrication and use as a fuel in existing or modified reactors in a once-through cycle, (2) vitrification with high-level radioactive waste for repository disposition, (3) burial in deep boreholes. As indicated in the NAS report, substantial effort would be required to address the broad range of issues related to deep bore-hole emplacement. Subjects reviewed in this report include geology and hydrology, design and engineering, safety and licensing, policy decisions that can impact the viability of the concept, and applicable international programs. Key technical areas that would require attention should decisions be made to further develop the borehole emplacement option are identified.

Ferguson, K.L.

1994-08-09

390

SAMPLING AND ANALYTICAL METHODOLOGY FOR ATMOSPHERIC PARTICULATE NITRATES  

EPA Science Inventory

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

391

Transactions of the ASABE UNCERTAINTIES IN ASSESSING ANNUAL NITRATE  

E-print Network

Transactions of the ASABE UNCERTAINTIES IN ASSESSING ANNUAL NITRATE LOADS AND CONCENTRATION the uncertainty in annual nitrate loads and concentrations (such as annual average and median concentrations, France, were analyzed. Original (high frequency) nitrate concentration and flow data were numerically

Paris-Sud XI, Université de

392

40 CFR 721.7500 - Nitrate polyether polyol (generic name).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Nitrate polyether polyol (generic name). ...Specific Chemical Substances § 721.7500 Nitrate polyether polyol (generic name). ...reporting. (1) The chemical substance nitrate polyether polyol (PMN...

2012-07-01

393

40 CFR 721.7500 - Nitrate polyether polyol (generic name).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Nitrate polyether polyol (generic name). ...Specific Chemical Substances § 721.7500 Nitrate polyether polyol (generic name). ...reporting. (1) The chemical substance nitrate polyether polyol (PMN...

2013-07-01

394

78 FR 32690 - Certain Ammonium Nitrate From Ukraine  

Federal Register 2010, 2011, 2012, 2013

...731-TA-894 (Review)] Certain Ammonium Nitrate From Ukraine Determination On the basis...antidumping duty order on certain ammonium nitrate from Ukraine would be likely to lead to...May 2013), entitled Certain Ammonium Nitrate from Ukraine: Investigation No....

2013-05-31

395

46 CFR 148.227 - Calcium nitrate fertilizers.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Calcium nitrate fertilizers. 148.227 Section...Materials § 148.227 Calcium nitrate fertilizers. This part does not apply to commercial grades of calcium nitrate fertilizers consisting mainly of...

2011-10-01

396

46 CFR 148.227 - Calcium nitrate fertilizers.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Calcium nitrate fertilizers. 148.227 Section...Materials § 148.227 Calcium nitrate fertilizers. This part does not apply to commercial grades of calcium nitrate fertilizers consisting mainly of...

2012-10-01

397

46 CFR 148.227 - Calcium nitrate fertilizers.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

398

70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM ...  

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

70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM NITRATE IN STORAGE. APRIL 18, 1919. - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

399

Dissimilatory nitrate reduction in Clostridium tertium.  

PubMed

Fermentation balance studies were carried out on Clostridium tertium grown with and without nitrate in the medium. Nitrate reduction increased the efficiency of energy produced from glucose by permitting the utilization of additional sites of substrate level phosphorylation. The effect was even more dramatic in C. tertium than in C. perfringens, with increased cell yields of about 30% being observed in the former compared with 20% in the latter. Unlike C. perfringens, C. tertium responded to the presence of nitrate in the medium with an increased growth rate. A slight increase in the Y ATP of these cultures was also observed, and quantitatively, this appeared to be consistent with the prediction of Stouthammer and Bettenhaussen that Y ATP will vary with the growth rate. Thus, C. tertium, like C. perfringens, was able to use nitrate as an electron acceptor in conjunction with its energy metabolism, suggesting that this may be widespread among the nitrate-reducing anaerobes. PMID:203129

Hasan, M; Hall, J B

1977-01-01

400

Nitrate removal from drinking water -- Review  

SciTech Connect

Nitrate concentrations in surface water and especially in ground water have increased in Canada, the US, Europe, and other areas of the world. This trend has raised concern because nitrates cause methemoglobiinemia in infants. Several treatment processes including ion exchange, biological denitrification, chemical denitrification, reverse osmosis, electrodialysis, and catalytic denitrification can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation. Available technical data, experience, and economics indicate that ion exchange and biological denitrification are more acceptable for nitrate removal than reverse osmosis. Ion exchange is more viable for ground water while biological denitrification is the preferred alternative for surface water. This paper reviews the developments in the field of nitrate removal processes.

Kapoor, A.; Viraraghavan, T. [Univ. of Regina, Saskatchewan (Canada)

1997-04-01

401

A vision for environmentally conscious plutonium processing  

SciTech Connect

Regardless of individual technical and political opinions about the uses of plutonium, it is virtually certain that plutonium processing will continue on a significant global scale for many decades for the purposes of national defense, nuclear power, and remediation. An unavoidable aspect of plutonium processing is that radioactively contaminated gas, liquid, and solid waste streams are generated. These streams need to be handled in a manner that not only is in full compliance with today`s laws but also will be considered environmentally and economically responsible now and in the future. In this regard, it is indeed ironic that the multibillion dollar and multidecade radioactive cleanup mortgage that the US Department of Energy (and its Russian counterpart) now owns resulted from waste management practices that were at the time in full legal compliance. It is now abundantly evident that in the long run, these practices have proven to be neither environmentally nor economically sound. Recent dramatic advances in actinide science and technology now make it possible to drastically minimize or even eliminate the problematic waste streams of traditional plutonium processing operations. Advanced technology thereby provides the means to avoid passing on to children and grandchildren significant environmental and economic legacies that traditional processing inevitably produces. The authors describe such a vision for plutonium processing that could be implemented fully within 5 yr at a facility such as the Los Alamos National Laboratory Plutonium Facility (TA55). As a significant bonus, even on this short timescale, the initial technology investment is handsomely returned in avoided waste management costs.

Avens, L.R.; Eller, P.G.; Christensen, D.C. [Los Alamos National Lab., NM (United States); Miller, W.L. [Univ. of Florida, Gainesville, FL (United States)

1998-12-31

402

Closure Welding of Plutonium Bearing Storage Containers  

SciTech Connect

A key element in the Department of Energy (DOE) strategy for the stabilization, packaging and storage of plutonium-bearing materials involves closure welding of DOE-STD-3013 Outer Containers (3013 container). The 3013 container provides the primary barrier and pressure boundary preventing release of plutonium-bearing materials to the environment. The final closure (closure weld) of the 3013 container must be leaktight, structurally sound and meet DOE STD 3013 specified criteria. This paper focuses on the development, qualification and demonstration of the welding process for the closure welding of Hanford PFP 3013 outer containers.

Cannell, G.R.

2002-02-28

403

Solubility of plutonium from rumen contents of cattle grazing on plutonium- contaminated desert vegetation in in vitro bovine gastrointestinal fluids  

Microsoft Academic Search

Rumen contents of cattle grazing on plutonium-contaminated desert ; vegetation at the Nevada Test Site were incubated in simulated bovine ; gastrointestinal fluids to study the alimentary solubility of plutonium. Trials ; were run during November 1973, and during February, May, July and August 1974. ; During the May and July trials, a large increase in plutonium solubility ; accompanied

J. Barth; M. G. White; P. B. Dunaway

1975-01-01

404

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

SciTech Connect

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

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

2004-07-02

405

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

PubMed Central

In fungi, transcriptional activation of genes involved in NO3- assimilation requires the presence of an inducer (nitrate or nitrite) and low intracellular concentrations of the pathway products ammonium or glutamine. In Aspergillus nidulans, the two transcription factors NirA and AreA act synergistically to mediate nitrate/nitrite induction and nitrogen metabolite derepression, respectively. In all studied fungi and in plants, mutants lacking nitrate reductase (NR) activity express nitrate-metabolizing enzymes constitutively without the addition of inducer molecules. Based on their work in A. nidulans, Cove and Pateman proposed an “autoregulation control” model for the synthesis of nitrate metabolizing enzymes in which the functional nitrate reductase molecule would act as co-repressor in the absence and as co-inducer in the presence of nitrate. However, NR mutants could simply show “pseudo-constitutivity” due to induction by nitrate which accumulates over time in NR-deficient strains. Here we examined this possibility using strains which lack flavohemoglobins (fhbs), and are thus unable to generate nitrate internally, in combination with nitrate transporter mutations (nrtA, nrtB) and a GFP-labeled NirA protein. Using different combinations of genotypes we demonstrate that nitrate transporters are functional also in NR null mutants and show that the constitutive phenotype of NR mutants is not due to nitrate accumulation from intracellular sources but depends on the activity of nitrate transporters. However, these transporters are not required for nitrate signaling because addition of external nitrate (10 mM) leads to standard induction of nitrate assimilatory genes in the nitrate transporter double mutants. We finally show that NR does not regulate NirA localization and activity, and thus the autoregulation model, in which NR would act as a co-repressor of NirA in the absence of nitrate, is unlikely to be correct. Results from this study instead suggest that transporter-mediated NO3- accumulation in NR deficient mutants, originating from traces of nitrate in the media, is responsible for the constitutive expression of NirA-regulated genes, and the associated phenotype is thus termed “pseudo-constitutive”. PMID:23454548

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

2013-01-01

406

IAEA activities on the safe handling and disposition of plutonium  

SciTech Connect

The buildup of the inventory of plutonium from dismantled warheads as well as from civilian nuclear programs and its disposition are under intense international debate. The activities of the IAEA in the technical area will be presented in this paper. It deals with (1) estimation of world wide inventories of civil plutonium both current and projected, (2) preparation of a safety document on safe handling and storage of plutonium, (3) exchange of information and discussion on some reactor technologies associated with the disposition of plutonium and it provides the necessary support to the ongoing initiatives for more transparency in management of plutonium.

Oi, N. [International Atomic Energy Agency, Vienna (Austria). Division of Nuclear Fuel Cycle and Waste Management

1995-12-31

407

Plutonium dispersal in fires: Summary of what is known  

SciTech Connect

In view of the great public apprehension about plutonium and nuclear weapons we should explore ways to prevent, limit, or mitigate possible plutonium dispersals. This review is primarily a tutorial on what is known about plutonium dispersal in fires. It concludes that in most types of fires involving plutonium the amount released will not be an immediate danger to life. Indeed, in many cases very few personnel will receive more than the lung burden allowed by current regulations for plutonium workers. However, the dangers may be significant in special situations, unusual terrains, certain meteorological conditions, and very high burn temperatures.

Condit, R.H.

1993-07-01

408

Six-kilogram-scale electrorefining of plutonium metal  

SciTech Connect

The electrorefining of metallic plutonium scrap to produce high purity metal has been an established procedure at Los Alamos since 1964. This is a batch process and was limited to 4-kg plutonium because of criticality safety considerations. Improvements in critical mass measurements have permitted us to develop a process for 6-kg plutonium. The 6-kg process is now operational. The increased size of the process, together with other improvements which have been made, makes plutonium electrorefining the principal industrial tool for processing and purifying metallic plutonium scrap.

Mullins, L.J.; Morgan, A.N.; Apgar, S.A. III; Christensen, D.C.

1982-09-01

409

A strategy for weapons-grade plutonium disposition  

SciTech Connect

A political as well as technical analysis was performed to determine the feasibility of glassification (vitrification) for weapons grade plutonium (WGPu) disposition. The political analysis provided the criteria necessary to compare alternative storage forms. The technical areas of weapon useability and environmental safety were then computationally and experimentally explored and a vitrification implementation strategy postulated. The Monte Carlo Neutron Photon (MCNP) computer code was used to model the effect of blending WGPu with reactor grade Pu (RGPu). A mixture of 30% RGPu and 70% WGPu more than doubled the surface flux from a bare sphere of the mixture which assumedly correlates to a significantly increased predetonation probability. Rare earth diluents were also examined (using MCNP) for their ability to increase the compressed critical mass of the WGPu mixture. The rare earths (notably Eu) were effective in this regard. As Pu-239 has a 24,100 year half life, reactivity control in the long term is an environmental safety issue. Rare earths were investigated as criticality controllers due to their neutron absorption capabilities and insolubility in aqueous environments. Thorium (a Pu surrogate) and the rare earths Eu, Gd, and Sm were added to two standard frits (ARM-1 and SRL-165) and formed into glass. Aqueous leach tests were performed (using MCC-1P guidelines) to measure rare earth leaching and determine the added elements` effects on glass durability. Europium was much more leach resistant than boron in the glasses tested. The elements had no negative effect on the environmental durability of the glasses tested at 90 C and minimal effect at room temperature. No fission product releases were detected in the ARM-1 compositions (which contained numerous simulated fission products).

Sylvester, K.W.B. [Iowa State Univ., Ames, IA (United States)

1994-09-01

410

Extraction of lanthanide(III) nitrates with composite solid extractants based on a polymeric support impregnated with trialkylmethylammonium nitrate or TBP  

Microsoft Academic Search

Extraction of lanthanides(III) and Y(III) from 1–5 M aqueous NaNO3 with composite solid extractants based on a polymeric support impregnated with trialkylmethylammonium nitrate (Aliquat-336)\\u000a or TBP was studied, and the extraction constants were determined. The extraction isotherms were analyzed assuming that lanthanides\\u000a are extracted with the solid extractants in the form of complexes (R4N)2[Ln(NO3)5] and Ln(NO3)3(TBP)3.

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

2006-01-01

411

NITRATE REDUCTION AND ASSIMILATION IN CHLORELLA  

PubMed Central

1. Nitrate reduction and assimilation have been studied in Chlorella pyrenoidosa under growth conditions by observing effects on the CO2/O2 gas exchange quotient. 2. During assimilation of glucose in the dark, nitrate reduction is noted as an increase in the R.Q. to about 1.6 caused by an increased rate of carbon dioxide production. 3. During photosynthesis at low light intensity nitrate reduction is evidenced by a reduction in the CO2O2 quotient to about 0.7 caused by a decreased rate of carbon dioxide uptake. 4. Chlorella will assimilate nitrogen from either nitrate or ammonia. When both sources are supplied, only ammonia is utilized and no nitrate reduction occurs. It is inferred that under the usual conditions of growth nitrate is reduced only at a rate required for subsequent cellular syntheses. The effect of nitrate reduction on the CO2O2 quotient therefore provides a measure of the relative rate of nitrogen assimilation. 5. Over-all photosynthetic metabolism may be described from elementary analysis of the cells since excretory products are negligible. The gas exchange predicted in this way is in good agreement with the observed CO2/O2 quotients. PMID:18885680

Cramer, Marian; Myers, Jack

1948-01-01

412

Microbial Uranium Immobilization Independent of Nitrate Reduction  

SciTech Connect

At many uranium processing and handling facilities, including sites in the U.S. Department of Energy (DOE) complex, high levels of nitrate are present as co-contamination with uranium in groundwater. The daunting prospect of complete nitrate removal prior to the reduction of uranium provides a strong incentive to explore bioremediation strategies that allow for uranium bioreduction and stabilization in the presence of nitrate. Typical in-situ strategies involving the stimulation of metal-reducing bacteria are hindered by low pH environments at this study site and require that the persistent nitrate must first and continuously be removed or transformed prior to uranium being a preferred electron acceptor. This project investigates the possibility of stimulating nitrate-indifferent, pH-tolerant microorganisms to achieve bioreduction of U(VI) despite nitrate persistence. Successful enrichments from U-contaminated sediments demonstrated nearly complete reduction of uranium with very little loss of nitrate from pH 4.9-5.6 using methanol or glycerol as a carbon source. Higher pH enrichments also demonstrated similar U reduction capacity with 5-30% nitrate loss within one week. Bacterial 16S rRNA genes were amplified from uranium-reducing enrichments (pH 5.7-6.7) and sequenced. Phylogenetic analyses classified the clone sequences into four distinct clusters. Data from sequencing and T-RFLP profiles indicated that the majority of the microorganisms stimulated by these enrichment conditions consisted of low G+C Gram-positive bacteria most closely related to Clostridium and Clostridium-like organisms. This research demonstrates that the stimulation of a natural microbial community to immobilize U through bioreduction is possible without the removal of nitrate.

Madden, Andrew [ORNL; Smith, April [Florida State University; Balkwill, Dr. David [Florida State University; Fagan, Lisa Anne [ORNL; Phelps, Tommy Joe [ORNL

2007-01-01

413

Water vapor adsorption on plutonium dioxide  

Microsoft Academic Search

Adsorption isotherms of water vapor on plutonium dioxide were measured ; gravimetrically at 30, 50, and 85 deg C. The data show water to be irreversibly ; chemisorbed until the oxide is saturated. Any subsequent adsorption is physical ; and completely reversible. The chemisorbed limit varied from 1 monolayer at 85 ; deg C to 3 monolayers at 30 deg

J. L. Stakebake; L. M. Steward

1973-01-01

414

PROSERPINE. HOMOGENEOUS CRITICAL EXPERIMENT WITH PLUTONIUM  

Microsoft Academic Search

The Proserpine, a zero power homogeneous reactor experiment with ; plutonium sulfate dissolved in light water, is briefly described. The lowest ; critical mass is 257.2 g of Pu. The vessel is of Zircaloy surrounded by a ; reflector of beryllium oxide. The absolute calibration of reactivlty by ; poisoning with boron and the study of the temperature coefficient in

Tachon

1958-01-01

415

Electrochemically Modulated Separation for Plutonium Safeguards  

SciTech Connect

Accurate and timely analysis of plutonium in spent nuclear fuel is critical in nuclear safeguards for detection of both protracted and rapid plutonium diversions. Gamma spectroscopy is a viable method for accurate and timely measurements of plutonium provided that the plutonium is well separated from the interfering fission and activation products present in spent nuclear fuel. Electrochemically modulated separation (EMS) is a method that has been used successfully to isolate picogram amounts of Pu from nitric acid matrices. With EMS, Pu adsorption may be turned "on" and "off" depending on the applied voltage, allowing for collection and stripping of Pu without the addition of chemical reagents. In this work, we have scaled up the EMS process to isolate microgram quantities of Pu from matrices encountered in spent nuclear fuel during reprocessing. Several challenges have been addressed including surface area limitations, radiolysis effects, electrochemical cell performance stability, and chemical interferences. After these challenges were resolved, 6 µg Pu was deposited in the electrochemical cell with approximately an 800-fold reduction of fission and activation product levels from a spent nuclear fuel sample. Modeling showed that these levels of Pu collection and interference reduction may not be sufficient for Pu detection by gamma spectroscopy. The main remaining challenges are to achieve a more complete Pu isolation and to deposit larger quantities of Pu for successful gamma analysis of Pu. If gamma analyses of Pu are successful, EMS will allow for accurate and timely on-site analysis for enhanced Pu safeguards.

Pratt, Sandra H.; Breshears, Andrew T.; Arrigo, Leah M.; Schwantes, Jon M.; Duckworth, Douglas C.

2013-12-31

416

Plutonium Immobilization Can Loading Equipment Review  

SciTech Connect

This report lists the operations required to complete the Can Loading steps on the Pu Immobilization Plant Flow Sheets and evaluates the equipment options to complete each operation. This report recommends the most appropriate equipment to support Plutonium Immobilization Can Loading operations.

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

1998-05-01

417

Proliferation Resistance Attributes of Advanced Plutonium Processing  

Microsoft Academic Search

To obtain public acceptance for future use of Pu, new concepts must overcome the present concerns about environmental compliance as well as con- cerns about misusing plutonium of the civil nuclear fuel cycle for nuclear explosives e.g. by terrorists. In future the preferable remedy is the multi-recycling of all transuranium elements in fast neutron reac- tors. In such a partitioning

L. Koch

418

Plutonium fractionation in southern Baltic Sea sediments  

Microsoft Academic Search

In this study, different chemical plutonium fractions (dissolved in water, connected to carbonates, connected to oxides, complexed with organic matter, mineral acids soluble and the rest) in sediments from the Vistula River estuary, the Gda?sk Basin and the Bornholm Deep were determined. The distribution of Pu in analysed sediments samples was not uniform but dependent on its chemical form, depth

Dagmara I. Strumi?ska-Parulska; Bogdan Skwarzec; Magdalena Pawlukowska

2012-01-01

419

Dissolution of plutonium dioxide in nitric acid  

SciTech Connect

Two alternative procedures of the electrochemical dissolution of plasmothermal plutonium dioxide in nitric acid were studied: reductive dissolution in the presence of U(IV) stabilized by hydrazine and dissolution in hot nitric acid at the alternating current supply. The current field accelerates dissolution of PuO{sub 2}.

Nikitina, G.P.; Zhukova, I.N.; Egorova, V.P. [Khlopin Radium Inst., St. Petersburg (Russian Federation)

1995-07-01

420

Plutonium Management in the Medium Term  

SciTech Connect

For many years various countries with access to commercial reprocessing services have been routinely recycling plutonium as UO{sub 2}/PuO{sub 2} mixed oxide (MOX) fuel in light water reactors (LWRs). This LWR MOX recycle strategy is still widely regarded as an interim step leading to the eventual establishment of sustainable fast reactor fuel cycles. The OECD/NEA Working Party on the Physics of Plutonium Fuels and Innovative Fuel Cycles (WPPR) has recently completed a review of the technical options for plutonium management in what it refers to as the 'medium term'. For the purpose of the review, the WPPR considers the medium term to cover the period from now up to the point at which fast reactor fuel cycles are established on a commercial scale. The review identified a number of different designs of innovative plutonium fuel assemblies intended to be used in current LWR cores, in LWRs with significantly different moderation properties, as well as in high-temperature gas reactors. The full review report describes these various options and highlights their respective advantages and disadvantages. This paper briefly summarizes the main findings of the review.

Hesketh, Kevin [BNFL Nuclear Sciences and Technology Services (United Kingdom); Schlosser, Gerhard; Porsch, Dieter F. [Framatome ANP (France); Wolf, Timm [Framatome ANP (France); Koeberl, Oliver [CEA Cadarache (France); Lance, Benoit [Belgonucleaire (Belgium); Chawla, Rakesh [Paul Scherrer Institut (Switzerland); Gehin, Jess C. [Oak Ridge National Laboratory (United States); Ellis, Ron [Oak Ridge National Laboratory (United States); Uchikawa, Sadao [Japan Atomic Energy Research Institute (Japan); Sato, Osamu [Japan Atomic Energy Research Institute (Japan); Okubo, Tsutomu [Japan Atomic Energy Research Institute (Japan); Mineo, Hideaki [Japan Atomic Energy Research Institute (Japan); Yamamoto, Toru [Nuclear Power Engineering Corporation (Japan); Sagayama, Yutaka [Japan Nuclear Cycle Development Institute (Japan); Sartori, Enrico [Organization for Economic Cooperation and Development (France)

2004-12-15

421

Photodegradation of Paracetamol in Nitrate Solution  

NASA Astrophysics Data System (ADS)

The photodegradation of paracetamol in nitrate solution under simulated solar irradiation has been investigated. The degradation rates were compared by varying environmental parameters including concentrations of nitrate ion, humic substance and pH values. The quantifications of paracetamol were conducted by HPLC method. The results demonstrate that the photodegradation of paracetamol followed first-order kinetics. The photoproducts and intermediates of paracetamol in the presence of nitrate ions were identified by extensive GC-MS method. The photodegradation pathways involving. OH radicals as reactive species were proposed.

Meng, Cui; Qu, Ruijuan; Liang, Jinyan; Yang, Xi

2010-11-01

422

Photodegradation of Paracetamol in Nitrate Solution  

SciTech Connect

The photodegradation of paracetamol in nitrate solution under simulated solar irradiation has been investigated. The degradation rates were compared by varying environmental parameters including concentrations of nitrate ion, humic substance and pH values. The quantifications of paracetamol were conducted by HPLC method. The results demonstrate that the photodegradation of paracetamol followed first-order kinetics. The photoproducts and intermediates of paracetamol in the presence of nitrate ions were identified by extensive GC-MS method. The photodegradation pathways involving. OH radicals as reactive species were proposed.

Meng Cui; Qu Ruijuan; Liang Jinyan; Yang Xi [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

2010-11-24

423

Nitrate(mg/L) Celldensity(10  

E-print Network

0 5 10 15 20 25 30 35 40 45 50 0 5 10 23 29 34 47 53 58 71 77 82 95 101 104 Time (h) Nitrate(mg/L) 0 5 10 15 20 25 30 35 40 45 Celldensity(10 5 cells/ml -1 ) 0 10 20 30 40 0 10 20 30 40 50 Nitrate 50 60 0 10 20 30 40 50 Nitrate(mg/L -1 ) 0 5 10 15 20 25 0 10 20 30 40 50 CellDensity(x105 cells/ml-1

Hall, Sharon J.

424

Nitrates and detinning in canned carrots  

E-print Network

in nitrate content was reported not only for dif- ferent vegetables, but between samples of the same vege- table. The maximum nitrate content reported in 1967 was 2, 957 ppm in a celery sample. The minimum was 11 ppm in a sample of canned tomatoes with a... carrot sample next with 18 ppm on a fresh weight basis. The range of nitrate levels was highest for carrots at 18 to 194 ppm for a ten fold difference. The minimum range for a vegetable was in celery with 2, 614 to 2, 957 ppm for only a 0. 1 fold dif...

Florine, Thomas Edward

2012-06-07

425

Ultraviolet irradiation effects incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter  

USGS Publications Warehouse

One of the concerns regarding the safety and efficacy of ultraviolet radiation for treatment of drinking water and wastewater is the fate of nitrate, particularly its photolysis to nitrite. In this study, 15N NMR was used to establish for the first time that UV irradiation effects the incorporation of nitrate and nitrite nitrogen into aquatic natural organic matter (NOM). Irradiation of 15N-labeled nitrate in aqueous solution with an unfiltered medium pressure mercury lamp resulted in the incorporation of nitrogen into Suwannee River NOM (SRNOM) via nitrosation and other reactions over a range of pH from approximately 3.2 to 8.0, both in the presence and absence of bicarbonate, confirming photonitrosation of the NOM. The major forms of the incorporated label include nitrosophenol, oxime/nitro, pyridine, nitrile, and amide nitrogens. Natural organic matter also catalyzed the reduction of nitrate to ammonia on irradiation. The nitrosophenol and oxime/nitro nitrogens were found to be susceptible to photodegradation on further irradiation when nitrate was removed from the system. At pH 7.5, unfiltered irradiation resulted in the incorporation of 15N-labeled nitrite into SRNOM in the form of amide, nitrile, and pyridine nitrogen. In the presence of bicarbonate at pH 7.4, Pyrex filtered (cutoff below 290–300 nm) irradiation also effected incorporation of nitrite into SRNOM as amide nitrogen. We speculate that nitrosation of NOM from the UV irradiation of nitrate also leads to production of nitrogen gas and nitrous oxide, a process that may be termed photo-chemodenitrification. Irradiation of SRNOM alone resulted in transformation or loss of naturally abundant heterocyclic nitrogens.

Thorn, Kevin A.; Cox, Larry G.

2012-01-01

426

Plutonium in the air in Kurchatov, Kazakhstan.  

PubMed

Weekly air samples of 25000 m(3) volume were taken with two air samplers over a period of one year in 2000-2001 in the town of Kurchatov in Kazakhstan. For another three-month period in 2001, the samplers were run in the city of Astana, about 500 km west of Kurchatov. (137)Cs, Pu and U concentrations were determined from the filters. Pu activities in Kurchatov varied in a 100-fold range; median (239,240)Pu activities were 100 nBq/m(3) and (238)Pu activities 34 nBq/m(3). The corresponding values for Astana were considerably lower: 29 and 9 nBq/m(3), respectively, and in half of the filters the (238)Pu activity was below the detection limit. Plutonium concentration correlated with the amount of dust retained on the filters only at the highest dust loads. Also no correlation between wind speed and the plutonium activity in the filters was observed. Thus, resuspension does not seem to be the mechanism responsible for the airborne plutonium. No clear seasonal variation of Pu air concentration was observed, though levels were somewhat elevated in February to April. There was no correlation between the plutonium and (137)Cs concentrations. In most of the filters the cesium concentration was below the detection limit, but in those filters where it could be detected the cesium concentration was practically constant at 3.9+/-1.6 microBq/m(3). Dose estimation for the inhalation of the airborne plutonium gave a low value of 0.018 microSv/a for the inhabitants in Kurchatov, which is about a thousand times lower than the dose caused by the naturally occurring (210)Po. Air parcel trajectory analysis indicated that the observed Pu activities in the air could not unambiguously be attributed to the most contaminated areas at the Semipalatinsk Test Site. PMID:16197982

Lehto, J; Salminen, S; Jaakkola, T; Outola, I; Pulli, S; Paatero, J; Tarvainen, M; Ristonmaa, S; Zilliacus, R; Ossintsev, A; Larin, V

2006-07-31

427

In search of plutonium: A nonproliferation journey  

NASA Astrophysics Data System (ADS)

In February 1992, I landed in the formerly secret city of Sarov, the Russian Los Alamos, followed a few days later by a visit to Snezhinsk, their Livermore. The briefings we received of the Russian nuclear weapons program and tours of their plutonium, reactor, explosives, and laser facilities were mind boggling considering the Soviet Union was dissolved only two months earlier. This visit began a 17-year, 41 journey relationship with the Russian nuclear complex dedicated to working with them in partnership to protect and safeguard their weapons and fissile materials, while addressing the plight of their scientists and engineers. In the process, we solved a forty-year disagreement about the plutonium-gallium phase diagram and began a series of fundamental plutonium science workshops that are now in their tenth year. At the Yonbyon reprocessing facility in January 2004, my North Korean hosts had hoped to convince me that they have a nuclear deterrent. When I expressed skepticism, they asked if I wanted to see their ``product.'' I asked if they meant the plutonium; they replied, ``Well, yes.'' Thus, I wound up holding 200 grams of North Korean plutonium (in a sealed glass jar) to make sure it was heavy and warm. So began the first of my six journeys to North Korea to provide technical input to the continuing North Korean nuclear puzzle. In Trombay and Kalpakkam a few years later I visited the Indian nuclear research centers to try to understand how India's ambitious plans for nuclear power expansion can be accomplished safely and securely. I will describe these and other attempts to deal with the nonproliferation legacy of the cold war and the new challenges ahead. )

Hecker, Siegfried

2010-02-01

428

Electrophilic and free radical nitration of benzene and toluene with various nitrating agents*  

PubMed Central

Electrophilic nitration of toluene and benzene was studied under various conditions with several nitrating systems. It was found that high orthopara regioselectivity is prevalent in all reactions and is independent of the reactivity of the nitrating agent. The methyl group of toluene is predominantly ortho-para directing under all reaction conditions. Steric factors are considered to be important but not the sole reason for the variation in the ortho/para ratio. The results reinforce our earlier views that, in electrophilic aromatic nitrations with reactive nitrating agents, substrate and positional selectivities are determined in two separate steps. The first step involves a ?-aromatic-NO2+ ion complex or encounter pair, whereas the subsequent step is of arenium ion nature (separate for the ortho, meta, and para positions). The former determines substrate selectivity, whereas the latter determines regioselectivity. Thermal free radical nitration of benzene and toluene with tetranitromethane in sharp contrast gave nearly statistical product distributions. PMID:16592503

Olah, George A.; Lin, Henry C.; Olah, Judith A.; Narang, Subhash C.

1978-01-01

429

Plutonium contamination in the environment. (Latest citations from Pollution abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the ecological impact of plutonium contamination in the environment. Topics include plutonium contamination in freshwater and marine sediments, plutonium bioaccumulation, plutonium transport in the food chain, plutonium accumulation in the soil, methods of analysis, plutonium removal from contaminated soils, and plutonium contamination from nuclear fallout and nuclear waste. Government regulations on containment and disposal of plutonium contaminated wastes are described. Government regulations regarding plutonium levels in consumer products and drinking water are discussed. (Contains a minimum of 208 citations and includes a subject term index and title list.)

Not Available

1993-05-01

430

Phase diagram of ammonium nitrate  

SciTech Connect

Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N{sub 2}, N{sub 2}O, and H{sub 2}O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV{sup ?} transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

Dunuwille, Mihindra; Yoo, Choong-Shik, E-mail: csyoo@wsu.edu [Department of Chemistry and Institute for Shock Physics, Washington State University, Pullman, Washington 99164 (United States)] [Department of Chemistry and Institute for Shock Physics, Washington State University, Pullman, Washington 99164 (United States)

2013-12-07

431

The capacity for nitrate regulation of root hydraulic properties correlates with species’ nitrate uptake rates  

Microsoft Academic Search

A mechanism whereby water flow towards root surfaces is stimulated when exposed to nutrient patches may be evolutionarily\\u000a desirable in environments with heterogeneous soils. Indeed, the presence of nitrate has been shown to increase root hydraulic\\u000a conductance in a few agricultural species characterized by high nitrate demand. Does a similar stimulation of root conductivity\\u000a in response to external nitrate addition

Anna Górska; Jillian W. Lazor; Anna K. Zwieniecka; Christopher Benway; Maciej A. Zwieniecki

2010-01-01

432

Phase equilibria and critical phenomena in a sodium nitrate-water-diethylamine ternary system  

NASA Astrophysics Data System (ADS)

The phase equilibria and critical phenomena in a sodium nitrate—water—diethylamine ternary system were studied by the visual polythermal method at 10—150°C, where the frontier binary liquid system is characterized by delamination with the lower critical solution temperature (LCST). The introduction of sodium nitrate into the water—diethylamine system led to a significant decrease (from 146.1 to 22.9°C) in the LCST of the system and the mutual solubility of its components. The coefficients of the distribution of diethylamine between the water and organic phases of the monotectic equilibrium at different temperatures were calculated. The effect of the salting-out of diethylamine by sodium nitrate from aqueous solutions increased with temperature. The constructed isotherms of the phase states of the system confirmed the general scheme of the topological transformation of the phase diagrams of the salt—binary solvent ternary systems with salting-out. The results of the salting-out action of sodi um, potassium, and cesium nitrates on the water—diethylamine binary system were compared.

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

2010-03-01

433

Qualitative Determination of Nitrate with Triphenylbenzylphosphonium Chloride.  

ERIC Educational Resources Information Center

Discusses two procedures for the identification of nitrate, the standard test ("Brown Ring" test) and a new procedure using triphenylbenzylphosphonium chloride (TPBPC). Effectiveness of both procedures is compared, with the TPBPC test proving to be more sensitive and accurate. (JM)

Berry, Donna A.; Cole, Jerry J.

1984-01-01

434

THE NITRATION OF POWDERED URANIUM BY NITROGEN  

Microsoft Academic Search

The nitration of powdered uranium by nitrogen was studied by- ; thermograviimetry- between 300 and 700 deg C. The results obtained show the ; complexity of a powdered soidgas reaction and chiefly the effect of granulometry. ; (trauth);

C. Moreau; J. Philippot

1961-01-01

435

The effect of x rays, DTPA, and aspirin on the absorption of plutonium from the gastrointestinal tract of rats  

SciTech Connect

To measure the effect of radiation on plutonium transport, rats that were exposed to 250-kVp X rays were given /sup 238/Pu 3 days afterwards by either gavage or injection into a ligated segment of the duodenum. In a second group of experiments, rats were either injected intraduodenally with /sup 238/Pu-DTPA or administered the chelate intravenously and the /sup 238/Pu by gavage. In a third experiment, rats that had been gavaged with 200 or 400 mg/kg/day of aspirin for 2 days were injected intragastrically with /sup 238/Pu nitrate. Results of the first experiment showed a dose-dependent increase in /sup 238/Pu absorption between 800 and 1500 rad of lower-body X irradiation. Intravenous or intraduodenal injections of DTPA caused a marked increase in /sup 238/Pu absorption but resulted in decreased plutonium deposition in the skeleton and liver. Retention of /sup 238/Pu in the skeleton of rats given aspirin was double that of controls, but the effect on plutonium absorption was less marked than that of DTPA.

Sullivan, M.F.; Gorham, L.S.; Miller, B.M.

1983-04-01

436

A Note on the Reaction of Hydrogen and Plutonium  

SciTech Connect

Plutonium hydride has many practical and experimental purposes. The reaction of plutonium and hydrogen has interesting characteristics, which will be explored in the following analysis. Plutonium is a radioactive actinide metal that emits alpha particles. When plutonium metal is exposed to air, the plutonium oxides and hydrides, and the volume increases. PuH{sub 2} and Pu{sub 2}O{sub 3} are the products. Hydrogen is a catalyst for plutonium's corrosion in air. The reaction can take place at room temperature because it is fairly insensitive to temperature. Plutonium hydride, or PuH{sub 2}, is black and metallic. After PuH{sub 2} is formed, it quickly flakes off and burns. The reaction of hydrogen and plutonium is described as pyrophoric because the product will spontaneously ignite when oxygen is present. This tendency must be considered in the storage of metal plutonium. The reaction is characterized as reversible and nonstoichiometric. The reaction goes as such: Pu + H{sub 2} {yields} PuH{sub 2}. When PuH{sub 2} is formed, the hydrogen/plutonium ratio is between 2 and 2.75 (approximately). As more hydrogen is added to the system, the ratio increases. When the ratio exceeds 2.75, PuH{sub 3} begins to form along with PuH{sub 2}. Once the ratio surpasses 2.9, only PuH{sub 3} remains. The volume of the plutonium sample increases because of the added hydrogen and the change in crystal structure which the sample undergoes. As more hydrogen is added to a system of metal plutonium, the crystal structure evolves. Plutonium has a crystal structure classified as monoclinic. A monoclinic crystal structure appears to be a rectangular prism. When plutonium reacts with hydrogen, the product PuH{sub 2}, becomes a fluorite structure. It can also be described as a face centered cubic structure. PuH{sub 3} forms a hexagonal crystal structure. As plutonium evolves from metal plutonium to plutonium hydride to plutonium trihydride, the crystal structure evolves from monoclinic to fluorite to hexagonal. This change in crystal structure as a result of adding hydrogen is a shared characteristic with other actinide elements. Americium is isostructural with plutonium because they both form cubic dihyrides and hexagonal trihydrides. Reacting hydrogen with plutonium has the practical application of separating plutonium from other materials that don't react as well with hydrogen. When plutonium is placed in a chamber where there is very little oxygen, it can react with hydrogen without igniting. The hydrogen plutonium reaction can then be reversed, thus regaining the separated plutonium. Another application of this reaction is that it can be used to predict how plutonium reacts with other substances. Deuterium and tritium are two isotopes of hydrogen that are of interest. They are known to react likewise to hydrogen because they have similar properties. The reaction of plutonium and isotopes of hydrogen can prove to be very informative.

Noone, Bailey C [Los Alamos National Laboratory

2012-08-15

437

Resuspension studies at Bikini Atoll. [Pulmonary exposure from dust-borne plutonium aerosols  

Microsoft Academic Search

The following experiments were conducted on Bikini Atoll to provide key parameters for an assessment of inhalation exposure from plutonium-contaminated dust aerosols: (1) a characterization of background (plutonium activity, dust, plutonium, sea spray, and organic aerosol concentrations); (2) a study of plutonium resuspension from a bare field; (3) a study of plutonium resuspension by traffic; and (4) a study of

J. H. Shinn; D. N. Homan; W. L. Robison

1980-01-01

438

Nitrate assimilation in the forage legume Lotus japonicus L  

Microsoft Academic Search

Nitrate assimilation in the model legume, Lotus japonicus, has been investigated using a variety of approaches. A gene encoding a nitrate-inducible nitrate reductase (NR) has been cloned and appears to be the only NR gene present in the genome. Most of the nitrate reductase activity (NRA) is found in the roots and the plant assimilates the bulk of its nitrogen

Ian M. Prosser; Agnes Massonneau; Audra J. Smyth; Rosi N. Waterhouse; Brian G. Forde; David T. Clarkson

2006-01-01

439

Original Articles Cytometric Quantification of Nitrate Reductase by  

E-print Network

Original Articles Cytometric Quantification of Nitrate Reductase by Immunolabeling in the Marine November 1999; Accepted 24 November 1999 Background: The uptake of nitrate by phytoplankton is a central of biogenic carbon. Nitrate reductase catalyzes the first step of nitrate assimilation, the reduction of NO3

Jochem, Frank J.

440

The distribution of nitrate 15 N in marine sediments  

E-print Network

The distribution of nitrate 15 N/14 N in marine sediments and the impact of benthic nitrogen loss on the isotopic composition of oceanic nitrate Moritz F. Lehmann a,*, Daniel M. Sigman b , Daniel C. McCorkle c 15 N/14 N ratios of porewater nitrate in sediments from the Bering Sea basin, where microbial nitrate

Sigman, Daniel M.

441

CHL1 Functions as a Nitrate Sensor in Plants  

E-print Network

CHL1 Functions as a Nitrate Sensor in Plants Cheng-Hsun HO,',2 Shan-Hua Lin,2Heng-Cheng HU,2 and Yi concentrations. Previous studies showed that T1 01-phosphorylated CHL1 is a high-affinity nitrate transporter- and sensing-decoupled mutant showed that the nitrate transporter CHL1 functions as a nitrate sensor. Primary

442

Supported bimetallic palladium catalysts for water-phase nitrate reduction  

Microsoft Academic Search

Technologies for the removal of nitrate from drinking water and waste water will be required in the near future, and the catalytic nitrate reduction is one of the most promising methods. So far, the understanding of nitrate reducing catalysts has been very poor. Experimental trends in nitrate removal activity and selectivity for various pH values, and for different bimetallic catalysts,

Ulf Prüsse; Klaus-Dieter Vorlop

2001-01-01

443

Tyrosine nitration in prostaglandin H(2) synthase  

Microsoft Academic Search

In this study, we investigated the effects of various nitrogen oxide (NO(x)) species on the extent of prostaglandin H(2) synthase-1 (PGHS-1) nitration in purified protein and in vascular smooth muscle cells. We also examined PGHS-1 activity under these conditions and found the degree of nitration to correlate inversely with enzyme activity. In addition, since NO(x) species are thought to invoke

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

2002-01-01

444

Protein Nitration in Placenta - Functional Significance  

PubMed Central

Crucial roles of the placenta are disrupted in early and mid-trimester pregnancy loss, preeclampsia, eclampsia and intrauterine growth restriction. The pathophysiology of these disorders includes a relative hypoxia of the placenta, ischemia/reperfusion injury, an inflammatory response and oxidative stress. Reactive oxygen species including nitric oxide (NO), carbon monoxide and superoxide have been shown to participate in trophoblast invasion, regulation of placental vascular reactivity and other events. Superoxide, which regulates expression of redox sensitive genes, has been implicated in up-regulation of transcription factors, antioxidant production, angiogenesis, proliferation and matrix remodeling. When superoxide and nitric oxide are present in abundance, their interaction yields peroxynitrite a potent pro-oxidant, but also alters levels of nitric oxide, which in turn affect physiological functions. The peroxynitrite anion is extremely unstable thus evidence of its formation in vivo has been indirect via the occurrence of nitrated moieties including nitrated lipids and nitrotyrosine residues in proteins. Formation of 3-nitrotyrosine (protein nitration) is a “molecular fingerprint” of peroxynitrite formation. Protein nitration has been widely reported in a number of pathological states associated with inflammation but is reported to occur in normal physiology and is thought of as a prevalent, functionally relevant post-translational modification of proteins. Nitration of proteins can give either no effect, a gain or a loss of function. Nitration of a range of placental proteins is found in normal pregnancy but increased in pathologic pregnancies. Evidence is presented for nitration of placental signal transduction enzymes and transporters. The targets and extent of nitration of enzymes, receptors, transporters and structural proteins may markedly influence placental cellular function in both physiologic and pathologic settings. PMID:18851882

Webster, RP; Roberts, VHJ; Myatt, L

2009-01-01

445

Low-level nitrate waste process development  

SciTech Connect

Chemical methods of denitrification of simulated low-level nitrate wastes were investigated on a laboratory scale. Various reducing agents and catalysts were tested in evaporation and drying experiments to determine denitrification efficiency, NO/sub x/ off-gas generation, and future process applicability. A peer review was conducted to gain input on processing needs and preferences from actual nitrate waste generators. Experimental results are discussed and conclusions presented. 10 tables.

Meile, L.J.; Johnson, A.J.

1984-01-01

446

Nitrate pollution of groundwater in northern China  

Microsoft Academic Search

Since the 1980s, nitrogen fertiliser consumption in China has increased substantially. High nitrogen application rates may increase the potential groundwater N-pollution. These effects were investigated in 14 cities and counties in northern China. The Merckoquant-nitrate-test strip was used to measure the nitrate concentration in water. Information on well depth, groundwater level, crop rotation, yield and fertiliser application was obtained.The results

W. L. Zhang; Z. X. Tian; N. Zhang; X. Q. Li

1996-01-01

447

Nitrate in aquifers beneath agricultural systems  

Microsoft Academic Search

Abstract Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater,vulnerability to nitrate contamination. Analysis of nationally consistent measurements,from the U.S. Geological Survey’s NAWQA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial

M. R. Burkart; J. D. Stoner

2007-01-01

448

The Purex thermodynamics of plutonium(IV) and uranium(VI) macroconcentrations coextraction into tri-n butylphosphate: new data and new models  

Microsoft Academic Search

The modern worldwide Purex technology (spent nuclear fuel reprocessing) is based on solvent extraction of actinides (U, Pu) in a system with aqueous nitric acid solutions and organic (n-paraffins) solutions of tri-n-butylphosphate (TBP).To the creation of a universal mathematical process model contributes - first of all - the knowledge of uranium(VI), plutonium(IV) and nitric acid equilibrated distribution data. Further should

Ed. V. Renard; A. A. Chizhov; V. S. Vlasov

1995-01-01

449

Reduction of nitrites and nitrates in aqueous phaseReduction of nitrites and nitrates in aqueous phase Roger Brunet Espinosa, Leon Lefferts  

E-print Network

purifying water are needed characterized by low cost and low energy consumption Goal: Develop efficient organic and inorganic compounds from water Proposal 2: Decrease the H2 concentration, without inducing any

Twente, Universiteit

450

Reflectance of aqueous solutions  

NASA Technical Reports Server (NTRS)

The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning extinction coefficients, relative specular reflectance, and temperature effect on the water spectrum. Graphs of absolute reflectance, phase shifts, index of refraction, and extinction coefficients for water, heavy water and aqueous solutions are included.

Querry, M. R.

1972-01-01

451

New aqueous magnetic fluids  

Microsoft Academic Search

New aqueous magnetic fluids constituted of nickel-zinc ferrite particles are synthesized using a soft chemical approach. Ferrofluids and solid particles are characterized using several techniques : chemical analysis, X-ray diffraction, transmission electron microscopy, infrared spectroscopy, and magnetization measurements.The stability of the aqueous magnetic fluids is studied as a function of pH and their magnetization is measured as a function of

D. Zins; V. Cabuil; R. Massart

1999-01-01

452

Stimulating nitrate removal processes of restored wetlands.  

PubMed

The environmental and health effects caused by nitrate contamination of aquatic systems are a serious problem throughout the world. A strategy proposed to address nitrate pollution is the restoration of wetlands. However, although natural wetlands often remove nitrate via high rates of denitrification, wetlands restored for water quality functions often fall below expectations. This may be in part because key drivers for denitrification, in particular soil carbon, are slow to develop in restored wetlands. We added organic soil amendments that range along a gradient of carbon lability to four newly restored wetlands in western New York to investigate the effect of carbon additions on denitrification and other processes of the nitrogen cycle. Soil carbon increased by 12.67-63.30% with the use of soil amendments (p ? 0.0001). Soil nitrate, the carbon to nitrogen ratio, and microbial biomass nitrogen were the most significant predictors of denitrification potential. Denitrification potential, potential net nitrogen nitrification and mineralization, and soil nitrate and ammonium, were highest in topsoil-amended plots, with increases in denitrification potential of 161.27% over control plots. While amendment with topsoil more than doubled several key nitrogen cycling processes, more research is required to determine what type and level of amendment application are most effective for stimulating removal of exogenous nitrate and meeting functional goals within an acceptable time frame. PMID:24915604

Ballantine, Kate A; Groffman, Peter M; Lehmann, Johannes; Schneider, Rebecca L

2014-07-01

453

Protein tyrosine nitration in the cell cycle  

SciTech Connect

Highlights: {yields} Enrichment of 3-nitrotyrosine containing proteins from cells synchronized in different phases of the cell cycle. {yields} Identification of 76 tyrosine nitrated proteins that change expression during the cell cycle. {yields} Nineteen identified proteins were previously described as regulators of cell proliferation. -- Abstract: Nitration of tyrosine residues in proteins is associated with cell response to oxidative/nitrosative stress. Tyrosine nitration is relatively low abundant post-translational modification that may affect protein functions. Little is known about the extent of protein tyrosine nitration in cells during progression through the cell cycle. Here we report identification of proteins enriched for tyrosine nitration in cells synchronized in G0/G1, S or G2/M phases of the cell cycle. We identified 27 proteins in cells synchronized in G0/G1 phase, 37 proteins in S phase synchronized cells, and 12 proteins related to G2/M phase. Nineteen of the identified proteins were previously described as regulators of cell proliferation. Thus, our data indicate which tyrosine nitrated proteins may affect regulation of the cell cycle.

Jia, Min, E-mail: min.jia@ki.se [Department of Oncology-Pathology, Karolinska Institutet, Stockholm (Sweden)] [Department of Oncology-Pathology, Karolinska Institutet, Stockholm (Sweden); Mateoiu, Claudia; Souchelnytskyi, Serhiy [Department of Oncology-Pathology, Karolinska Institutet, Stockholm (Sweden)] [Department of Oncology-Pathology, Karolinska Institutet, Stockholm (Sweden)

2011-09-23

454

Origin of the deep Bering Sea nitrate deficit: Constraints from the nitrogen and oxygen isotopic composition of water column nitrate  

E-print Network

Origin of the deep Bering Sea nitrate deficit: Constraints from the nitrogen and oxygen isotopic composition of water column nitrate and benthic nitrate fluxes Moritz F. Lehmann,1,2 Daniel M. Sigman,1 Daniel. [1] On the basis of the normalization to phosphate, a significant amount of nitrate is missing from

Sigman, Daniel M.

455

Differential Effect of Tungsten on the Development of Endogenous and Nitrate-Induced Nitrate Reductase Activities in Soybean Leaves 1  

PubMed Central

The effect of tungsten on the development of endogenous and nitrate-induced NADH- and FMNH2-linked nitrate reductase activities in primary leaves of 10-day-old soybean (Glycine max [L.] Merr.) seedlings was studied. The seedlings were grown with or without exogenous nitrate. High levels of endogenous nitrate reductase activities developed in leaves of seedlings grown without nitrate. However, no endogenous nitrite reductase activity was detected in such seedlings. The FMNH2-linked nitrate reductase activity was about 40% of NADH-linked activity. Tungsten had little or no effect on the development of endogenous NADH- and FMNH2-linked nitrate reductase activities, respectively. By contrast, in nitrate-grown seedlings, tungsten only inhibited the nitrate-induced portion of NADH-linked nitrate reductase activity, whereas the FMNH2-linked activity was inhibited completely. Tungsten had no effect on the development of nitrate-induced nitrite reductase activity. The complete inhibition of FMNH2-linked nitrate reductase activity by tungsten in nitrate-grown plants was apparently an artifact caused by the reduction of nitrite by nitrite reductase in the assay system. The results suggest that in soybean leaves either the endogenous nitrate reductase does not require molybdenum or the molybdenum present in the seed is preferentially utilized by the enzyme complex as compared to nitrate-induced nitrate reductase. PMID:16662475

Aslam, Muhammad

1982-01-01

456

Thermal expansion of nitrates of lead, barium and strontium  

Microsoft Academic Search

The expansion coefficients of barium, strontium and lead nitrates have been studied above room temperatures. Lead nitrate\\u000a decomposes rapidly beyond 200° C. while crystals of barium nitrate crack above 270° C. Strontium nitrate exhibited no such\\u000a phenomena till 550° C.\\u000a \\u000a These crystals are isomorphous. The expansion coefficients of lead and strontium nitrates are nearly equal; they also possess\\u000a the same

R. Srinivasan

1955-01-01

457

Nitrate in groundwater in the United States  

NASA Astrophysics Data System (ADS)

An assessment of nitrate concentrations in groundwater in the United States (US) indicates that concentrations are highest in shallow, oxic groundwater beneath areas with high nitrogen inputs. During 1991-2003, 5,101 wells were sampled in 51 study areas throughout the US as part of the USGS National Water-Quality Assessment program. Well locations for individual 30-well networks were selected for sampling using a computerized, stratified, random site-selection procedure to minimize spatial bias. These well networks reflect the existing used resource in major aquifers represented by domestic wells (major aquifer studies), and recently recharged groundwater beneath dominant land-surface activities (land-use studies). Nitrate concentrations in groundwater were compared with nationally-available variables such as nonpoint-source nitrogen inputs, soils, water chemistry, and other aquifer and well construction characteristics to predict the conditions most vulnerable to high nitrate concentrations. Nitrate was detected at concentrations above background of 1.0 mg/L (as N) in 50% of the wells sampled. Shallow groundwater beneath agricultural land had the highest median concentration of nitrate (3.1 mg/L). Median nitrate in shallow groundwater beneath urban land (1.4 mg/L) was lower than beneath agricultural land, but was higher than the median in major aquifers (0.56 mg/L). Although most wells sampled in the shallow land-use studies were not used for drinking water, concentrations exceeded the US EPA drinking-water standard (MCL) of 10 mg/L in 20% of wells in the agricultural land-use setting. Concentrations exceeded the MCL in only 3% of wells in the urban land-use setting, and 4% of wells in major aquifers. Classification and regression tree analysis was used to identify the relative importance of nitrogen inputs, water chemistry, and physical aquifer properties on nitrate concentrations in groundwater. Factors ranked by reduction in sum of squares indicate that dissolved iron concentrations explained most of the variation in groundwater nitrate concentration, followed by manganese, calcium, farm fertilizer, percent well-drained soils, dissolved oxygen, and other chemical and physical factors. The high rankings of iron, manganese, and farm fertilizer indicate that nitrate concentrations in groundwater are most significantly affected by redox conditions and nonpoint-source nitrogen inputs. The other water-quality indicators and physical variables have a secondary influence on nitrate concentrations.

Burow, K. R.; Nolan, B. T.; Rupert, M. G.; Dubrovsky, N. M.

2009-12-01

458

Radiation-chemical reduction of plutonium(VI) in nitric acid solutions. Influence of palladium(II) and uranium(VI) ions  

SciTech Connect

The influence of uranium(VI) and palladium(II) on the radiation-chemical reduction of plutonium(VI) in 4 M nitric acid was investigated. A quadratic dependence of the maximum yield of the reduction of Pu(VI) on the total plutonium concentration in the range 0.008-0.1 M was detected in the presence of uranyl nitrate, explained by competition of the reaction of Pu(III) and Pu(V), determining the rate of the process, with their oxidation by OH and NO/sub 3/ radicals and by nitrous acid. The rate constant of the interaction of oxidizing radicals with pentavlent plutonium was estimated according to the experimental data using a mathematical model. The accelerating action of palladium(II) on the radiolytic reduction of hexavalent plutonium is explained by its rapid interaction with OH and NO/sub 3/ radicals. Hexavalent uranium accelerates the determining step, and also serves as a source of formation of an effective reducing agent-pentavalent uranium.

Tkhorzhnitshii, G.P.; Egorov, G.F.

1985-11-01

459

Tracing the source and fate of nitrate in contemporary mixed land-use surface water systems  

NASA Astrophysics Data System (ADS)

Nitrogenous fertilizers increase agricultural productivity, ultimately feeding the planet. Yet, it is possible to have too much of a good thing, and nitrogen is no exception. When in excess nitrogen has been shown to accelerate eutrophication of water bodies, and act as a chronic toxin (e.g. methemoglobinemia). As land-use intensity continues to rise in response to increases in agricultural productivity, the risk of adverse effects of nitrogen loading on surface water bodies will also increase. Stable isotope proxies are potential tracers of nitrate, the most common nitrogenous phase in surface waters. Applying stable isotope proxies therefore presents an opportunity to identify and manage sources of excess nitrogen before aquatic systems are severely degraded. However, the heterogeneous nature of potential pollution sources themselves, and their distribution with a modified catchment network, make understanding this issue highly complex. The Banks Peninsula, an eroded late tertiary volcanic complex located on the east coast of the South Island New Zealand, presents a unique opportunity to study and understand the sources and fates of nitrate within streams in a contemporary mixed land-use setting. Within this small geographic area there a variety of agricultural activities are practiced, including: heavily fertilized golf courses; stands of regenerating native forest; and areas of fallow gorse (Ulex europaeus; a invasive N-fixing shrub). Each of these landuse classes has its own unique nitrogen budget. Multivariate analysis was used on stream nitrate concentrations to reveal that stream reaches dominated by gorse had significantly higher nitrate concentrations than other land-use classes. Nitrate ?15N & ?18O data from these sites show strong covariance, plotting along a distinct fractionation line (r2 = 0.96). This finding facilitates interpretation of what processes are controlling nitrate concentration within these systems. Further, complementary aquatic foodweb ?15N ?13C analyses of multiple species in various trophic positions allow for a unique, holistic insight in to the fate of gorse-derived nitrate at an ecosystem level. We present here physicochemical and stable isotopic data from a variety of aqueous and aquatic foodweb components. Data is generated using emerging and established analytical techniques, in order to explore links between foodweb ecology, ecosystem function, and fate and transport of excess nitrate along longitudinal gradients of mixed land-use catchments.

Stewart, S. D.; Young, M. B.; Horton, T. W.; Harding, J. S.

2011-12-01

460

Plutonium disposition via immobilization in ceramic or glass  

SciTech Connect

The management of surplus weapons plutonium is an important and urgent task with profound environmental, national, and international security implications. In the aftermath of the Cold War, Presidential Policy Directive 13, and various analyses by renown scientific, technical, and international policy organizations have brought about a focused effort within the Department of Energy to identify and implement paths for the long term disposition of surplus weapons- usable plutonium. The central goal of this effort is to render surplus weapons plutonium as inaccessible and unattractive for reuse in nuclear weapons as the much larger and growing stock of plutonium contained in spent fuel from civilian reactors. One disposition option being considered for surplus plutonium is immobilization, in which the plutonium would be incorporated into a glass or ceramic material that would ultimately be entombed permanently in a geologic repository for high-level waste.

Gray, L.W.; Kan, T.; Shaw, H.F.; Armantrout, A.

1997-03-05

461

Los Alamos Plutonium Facility Waste Management System  

SciTech Connect

This paper describes the new computer-based transuranic (TRU) Waste Management System (WMS) being implemented at the Plutonium Facility at Los Alamos National Laboratory (LANL). The Waste Management System is a distributed computer processing system stored in a Sybase database and accessed by a graphical user interface (GUI) written in Omnis7. It resides on the local area network at the Plutonium Facility and is accessible by authorized TRU waste originators, count room personnel, radiation protection technicians (RPTs), quality assurance personnel, and waste management personnel for data input and verification. Future goals include bringing outside groups like the LANL Waste Management Facility on-line to participate in this streamlined system. The WMS is changing the TRU paper trail into a computer trail, saving time and eliminating errors and inconsistencies in the process.

Smith, K.; Montoya, A.; Wieneke, R.; Wulff, D.; Smith, C.; Gruetzmacher, K.

1997-02-01

462

Purification of plutonium via electromagnetic levitation  

NASA Astrophysics Data System (ADS)

Plutonium metal that has been double electrorefined (ER) was further purified via zone refining, using a levitated molten zone to minimize the introduction of impurities. The temperature of the molten zone was 750 °C, and the atmosphere was 10-5 Pa. A total of ten zone refining passes were made at a travel rate of 1.5 cm/hr. In order to study the efficiency of the zone refining process, core samples were taken after every two zone refining passes in five locations along the length plutonium specimen. Several impurities were reduced to levels below that of instrument detection limits, and it appears that six sequential zone refining passes are required to obtain the highest purity metal.

Lashley, J. C.; Blau, M. S.; Quagliano, J. R.

2000-07-01