Isotopic fractionation studies of uranium and plutonium using porous ion emitters as thermal ionization mass spectrometry sources

DOE PAGES

Baruzzini, Matthew L.; Hall, Howard L.; Spencer, Khalil J.; ...

2018-04-22

Investigations of the isotope fractionation behaviors of plutonium and uranium reference standards were conducted employing platinum and rhenium (Pt/Re) porous ion emitter (PIE) sources, a relatively new thermal ionization mass spectrometry (TIMS) ion source strategy. The suitability of commonly employed, empirically developed mass bias correction laws (i.e., the Linear, Power, and Russell's laws) for correcting such isotope ratio data was also determined. Corrected plutonium isotope ratio data, regardless of mass bias correction strategy, were statistically identical to that of the certificate, however, the process of isotope fractionation behavior of plutonium using the adopted experimental conditions was determined to be bestmore » described by the Power law. Finally, the fractionation behavior of uranium, using the analytical conditions described herein, is also most suitably modeled using the Power law, though Russell's and the Linear law for mass bias correction rendered results that were identical, within uncertainty, to the certificate value.« less

Isotopic fractionation studies of uranium and plutonium using porous ion emitters as thermal ionization mass spectrometry sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baruzzini, Matthew L.; Hall, Howard L.; Spencer, Khalil J.

Investigations of the isotope fractionation behaviors of plutonium and uranium reference standards were conducted employing platinum and rhenium (Pt/Re) porous ion emitter (PIE) sources, a relatively new thermal ionization mass spectrometry (TIMS) ion source strategy. The suitability of commonly employed, empirically developed mass bias correction laws (i.e., the Linear, Power, and Russell's laws) for correcting such isotope ratio data was also determined. Corrected plutonium isotope ratio data, regardless of mass bias correction strategy, were statistically identical to that of the certificate, however, the process of isotope fractionation behavior of plutonium using the adopted experimental conditions was determined to be bestmore » described by the Power law. Finally, the fractionation behavior of uranium, using the analytical conditions described herein, is also most suitably modeled using the Power law, though Russell's and the Linear law for mass bias correction rendered results that were identical, within uncertainty, to the certificate value.« less

The plutonium isotopic composition of marine biota on Enewetak Atoll: a preliminary assessment.

PubMed

Hamilton, Terry F; Martinelli, Roger E; Kehl, Steven R; McAninch, Jeffrey E

2008-10-01

We have determined the level and distribution of gamma-emitting radionuclides, plutonium activity concentrations, and 240Pu/239Pu atom ratios in tissue samples of giant clam (Tridacna gigas and Hippopus hippopus), a top snail (Trochus nilaticas) and sea cucumber (Holothuria atra) collected from different locations around Enewetak Atoll. The plutonium isotopic measurements were performed using ultra-high sensitivity accelerator mass spectrometry (AMS). Elevated levels of plutonium were observed in the stomachs (includes the stomach lining) of Tridacna clam (0.62 to 2.98 Bq kg(-1), wet wt.), in the soft parts (edible portion) of top snails (0.25 to 1.7 Bq kg(-1)), wet wt.) and, to a lesser extent, in sea cucumber (0.015 to 0.22 Bq kg(-1), wet wt.) relative to muscle tissue concentrations in clam (0.006 to 0.021 Bq kg(-1), wet wt.) and in comparison with previous measurements of plutonium in fish. These data and information provide a basis for re-evaluating the relative significance of dietary intakes of plutonium from marine foods on Enewetak Atoll and, perhaps most importantly, demonstrate that discrete 240Pu239Pu isotope signatures might well provide a useful investigative tool to monitor source-term attribution and consequences on Enewetak Atoll. One potential application of immediate interest is to monitor and assess the health and ecological impacts of leakage of plutonium (as well as other radionuclides) from a low-level radioactive waste repository on Runit Island relative to background levels of fallout contamination in Enewetak Atoll lagoon.

Determination of plutonium isotopes (238,239,240Pu) and strontium (90Sr) in seafood using alpha spectrometry and liquid scintillation spectrometry.

PubMed

Shin, Choonshik; Choi, Hoon; Kwon, Hye-Min; Jo, Hye-Jin; Kim, Hye-Jeong; Yoon, Hae-Jung; Kim, Dong-Sul; Kang, Gil-Jin

2017-10-01

The present study was carried out to survey the levels of plutonium isotopes ( 238 , 239 , 240 Pu) and strontium ( 90 Sr) in domestic seafood in Korea. In current, regulatory authorities have analyzed radionuclides, such as 134 Cs, 137 Cs and 131 I, in domestic and imported food. However, people are concerned about contamination of other radionuclides, such as plutonium and strontium, in food. Furthermore, people who live in Korea have much concern about safety of seafood. Accordingly, in this study, we have investigated the activity concentrations of plutonium and strontium in seafood. For the analysis of plutonium isotopes and strontium, a rapid and reliable method developed from previous study was used. Applicability of the test method was verified by examining recovery, minimum detectable activity (MDA), analytical time, etc. Total 40 seafood samples were analyzed in 2014-2015. As a result, plutonium isotopes ( 238 , 239 , 240 Pu) and strontium ( 90 Sr) were not detected or below detection limits in seafood. The detection limits of plutonium isotopes and strontium-90 were 0.01 and 1 Bq/kg, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

PLUTONIUM CLEANING PROCESS

DOEpatents

Kolodney, M.

1959-12-01

A method is described for rapidly removing iron, nickel, and zinc coatings from plutonium objects while simultaneously rendering the plutonium object passive. The method consists of immersing the coated plutonium object in an aqueous acid solution containing a substantial concentration of nitrate ions, such as fuming nitric acid.

Isotopic Analysis of Plutonium by Optical Spectroscopy; ANALYSE ISOTOPIQUE DU PLUTONIUM PAR SPECTROSCOPIE OPTIQUE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Artaud, J.; Chaput, M.; Gerstenkorn, S.

1961-01-01

Isotopic analyses of mixtures of plutonium-239 and -240 were carried out by means of the photoelectric spectrometer, the source being a hollow cathode cooled by liquid nitrogen. The relative precision is of the order of 2%, for samples containieg 3% of Pu/sup 240/. The study of the reproductibility of the measurements should make it possible to increase the precision; the relative precision which can be expected from the method should be 1% for mixtures containing 1% of Pu/sup 240/. (auth)

Measurement of plutonium isotope ratios in nuclear fuel samples by HPLC-MC-ICP-MS

NASA Astrophysics Data System (ADS)

Günther-Leopold, I.; Waldis, J. Kobler; Wernli, B.; Kopajtic, Z.

2005-04-01

Radioactive isotopes are traditionally quantified by means of radioactivity counting techniques ([alpha], [beta], [gamma]). However, these methods often require extensive matrix separation and sample purification before the identification of specific isotopes and their relative abundance is possible as it is necessary in the frame of post-irradiation examinations on nuclear fuel samples. The technique of multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) is attracting much attention because it permits the precise measurement of the isotope compositions for a wide range of elements combined with excellent limits of detection due to high ionization efficiencies. The present paper describes one of the first applications of an online high-performance liquid chromatographic separation system coupled to a MC-ICP-MS in order to overcome isobaric interferences for the determination of the plutonium isotope composition and concentrations in irradiated nuclear fuels. The described chromatographic separation is sufficient to prevent any isobaric interference between 238Pu present at trace concentrations and 238U present as the main component of the fuel samples. The external reproducibility of the uncorrected plutonium isotope ratios was determined to be between 0.04 and 0.2% (2 s) resulting in a precision in the [per mille sign] range for the isotopic vectors of the irradiated fuel samples.

Isotope ratio measurements of pg-size plutonium samples using TIMS in combination with "multiple ion counting" and filament carburization

NASA Astrophysics Data System (ADS)

Jakopic, Rozle; Richter, Stephan; Kühn, Heinz; Benedik, Ljudmila; Pihlar, Boris; Aregbe, Yetunde

2009-01-01

A sample preparation procedure for isotopic measurements using thermal ionization mass spectrometry (TIMS) was developed which employs the technique of carburization of rhenium filaments. Carburized filaments were prepared in a special vacuum chamber in which the filaments were exposed to benzene vapour as a carbon supply and carburized electrothermally. To find the optimal conditions for the carburization and isotopic measurements using TIMS, the influence of various parameters such as benzene pressure, carburization current and the exposure time were tested. As a result, carburization of the filaments improved the overall efficiency by one order of magnitude. Additionally, a new "multi-dynamic" measurement technique was developed for Pu isotope ratio measurements using a "multiple ion counting" (MIC) system. This technique was combined with filament carburization and applied to the NBL-137 isotopic standard and samples of the NUSIMEP 5 inter-laboratory comparison campaign, which included certified plutonium materials at the ppt-level. The multi-dynamic measurement technique for plutonium, in combination with filament carburization, has been shown to significantly improve the precision and accuracy for isotopic analysis of environmental samples with low-levels of plutonium.

STRIPPING PROCESS FOR PLUTONIUM

DOEpatents

Kolodney, M.

1959-10-01

A method for removing silver, nickel, cadmium, zinc, and indium coatings from plutonium objects while simultaneously rendering the plutonium object passive is described. The coated plutonium object is immersed as the anode in an electrolyte in which the plutonium is passive and the coating metal is not passive, using as a cathode a metal which does not dissolve rapidly in the electrolyte. and passing an electrical current through the electrolyte until the coating metal is removed from the plutonium body.

Lithium metal reduction of plutonium oxide to produce plutonium metal

DOEpatents

Coops, Melvin S.

1992-01-01

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

A critical examination of the possible application of zinc stable isotope ratios in bivalve mollusks and suspended particulate matter to trace zinc pollution in a tropical estuary.

PubMed

Araújo, Daniel; Machado, Wilson; Weiss, Dominik; Mulholland, Daniel S; Boaventura, Geraldo R; Viers, Jerome; Garnier, Jeremie; Dantas, Elton L; Babinski, Marly

2017-07-01

The application of zinc (Zn) isotopes in bivalve tissues to identify zinc sources in estuaries was critically assessed. We determined the zinc isotope composition of mollusks (Crassostrea brasiliana and Perna perna) and suspended particulate matter (SPM) in a tropical estuary (Sepetiba Bay, Brazil) historically impacted by metallurgical activities. The zinc isotope systematics of the SPM was in line with mixing of zinc derived from fluvial material and from metallurgical activities. In contrast, source mixing alone cannot account for the isotope ratios observed in the bivalves, which are significantly lighter in the contaminated metallurgical zone (δ 66 Zn JMC  = +0.49 ± 0.06‰, 2σ, n = 3) compared to sampling locations outside (δ 66 Zn JMC  = +0.83 ± 0.10‰, 2σ, n = 22). This observation suggests that additional factors such as speciation, bioavailability and bioaccumulation pathways (via solution or particulate matter) influence the zinc isotope composition of bivalves. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heterogeneous sodium fast reactor designed for transmuting minor actinide waste isotopes into plutonium fuel

NASA Astrophysics Data System (ADS)

Bays, Samuel Eugene

2008-10-01

In the past several years there has been a renewed interest in sodium fast reactor (SFR) technology for the purpose of destroying transuranic waste (TRU) produced by light water reactors (LWR). The utility of SFRs as waste burners is due to the fact that higher neutron energies allow all of the actinides, including the minor actinides (MA), to contribute to fission. It is well understood that many of the design issues of LWR spent nuclear fuel (SNF) disposal in a geologic repository are linked to MAs. Because the probability of fission for essentially all the "non-fissile" MAs is nearly zero at low neutron energies, these isotopes act as a neutron capture sink in most thermal reactor systems. Furthermore, because most of the isotopes produced by these capture reactions are also non-fissile, they too are neutron sinks in most thermal reactor systems. Conversely, with high neutron energies, the MAs can produce neutrons by fast fission. Additionally, capture reactions transmute the MAs into mostly plutonium isotopes, which can fission more readily at any energy. The transmutation of non-fissile into fissile atoms is the premise of the plutonium breeder reactor. In a breeder reactor, not only does the non-fissile "fertile" U-238 atom contribute fast fission neutrons, but also transmutes into fissile Pu-239. The fissile value of the plutonium produced by MA transmutation can only be realized in fast neutron spectra. This is due to the fact that the predominate isotope produced by MA transmutation, Pu-238, is itself not fissile. However, the Pu-238 fission cross section is significantly larger than the original transmutation parent, predominately: Np-237 and Am-241, in the fast energy range. Also, Pu-238's fission cross section and fission-to-capture ratio is almost as high as that of fissile Pu-239 in the fast neutron spectrum. It is also important to note that a neutron absorption in Pu-238, that does not cause fission, will instead produce fissile Pu-239. Given this

Low-energy Coulomb excitation of neutron-rich zinc isotopes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walle, J. van de; ISOLDE, CERN, Geneva; Aksouh, F.

2009-01-15

At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,2{sub 1}{sup +}{yields}0{sub 1}{sup +}) values in {sup 74-80}Zn, B(E2,4{sub 1}{sup +}{yields}2{sub 1}{sup +}) values in {sup 74,76}Zn and the determination of the energy of the first excited 2{sub 1}{sup +} states in {sup 78,80}Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of {sup 238}U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondarymore » target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, including a recent empirical residual interaction constructed to describe the present experimental data up to 2004 in this region of the nuclear chart.« less

DELTA PHASE PLUTONIUM ALLOYS

DOEpatents

Cramer, E.M.; Ellinger, F.H.; Land. C.C.

1960-03-22

Delta-phase plutonium alloys were developed suitable for use as reactor fuels. The alloys consist of from 1 to 4 at.% zinc and the balance plutonium. The alloys have good neutronic, corrosion, and fabrication characteristics snd possess good dimensional characteristics throughout an operating temperature range from 300 to 490 deg C.

METHOD OF SEPARATING PLUTONIUM

DOEpatents

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

1958-02-01

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

Plutonium Isotopes in the Terrestrial Environment at the Savannah River Site, USA. A Long-Term Study

DOE PAGES

Armstrong, Christopher R.; Nuessle, Patterson R.; Brant, Heather A.; ...

2015-01-16

This work presents the findings of a long term plutonium study at Savannah River Site (SRS) conducted between 2003 and 2013. Terrestrial environmental samples were obtained at Savannah River National Laboratory (SRNL) in A-area. Plutonium content and isotopic abundances were measured over this time period by alpha spectrometry and three stage thermal ionization mass spectrometry (3STIMS). Here we detail the complete sample collection, radiochemical separation, and measurement procedure specifically targeted to trace plutonium in bulk environmental samples. Total plutonium activities were determined to be not significantly above atmospheric global fallout. However, the 238Pu/ 239+240Pu activity ratios attributed to SRS aremore » above atmospheric global fallout ranges. The 240Pu/ 239Pu atom ratios are reasonably consistent from year to year and are lower than fallout, while the 242Pu/ 239Pu atom ratios are higher than fallout values. Overall, the plutonium signatures obtained in this study reflect a mixture of weapons-grade, higher burn-up, and fallout material. This study provides a blue print for long term low level monitoring of plutonium in the environment.« less

Estimation of Plutonium-240 Mass in Waste Tanks Using Ultra-Sensitive Detection of Radioactive Xenon Isotopes from Spontaneous Fission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowyer, Theodore W.; Gesh, Christopher J.; Haas, Daniel A.

This report details efforts to develop a technique which is able to detect and quantify the mass of 240Pu in waste storage tanks and other enclosed spaces. If the isotopic ratios of the plutonium contained in the enclosed space is also known, then this technique is capable of estimating the total mass of the plutonium without physical sample retrieval and radiochemical analysis of hazardous material. Results utilizing this technique are reported for a Hanford Site waste tank (TX-118) and a well-characterized plutonium sample in a laboratory environment.

In-Vivo Zinc Metabolism by Isotope Ratio Mass Spectrometry

USDA-ARS?s Scientific Manuscript database

The purpose of this chapter is to highlight some of the methodological and technical issues surrounding the in vivo use of stable isotopes and to provide examples of how such studies have advanced our knowledge of human zinc metabolism. The advantages and disadvantages of the currently available in...

Zinc Isotopic Signatures of the Upper Continental Crust

NASA Astrophysics Data System (ADS)

Xia, Y.; Zhang, X.; Zhang, H.; Huang, F.

2016-12-01

To examine the Zn isotope systematics within the Upper Continental Crust (UCC), and isotope fractionation during chemical weathering in large spatial and temporal scales, we analyzed Zn isotopic compositions of loess, glacial diamictites, river sediments, and igneous rocks (samples in total 77). The Zn isotopic compositions (δ66Zn relative to JMC-Lyon) of loess display a limited variation (0.17‰ to 0.29‰), which is negatively correlated with Zn content and proxies for chemical weathering (e.g. CIA values), reflect the impact of chemical weathering. Glacial diamictites have more variable δ66Zn (0.09‰ to 0.48‰), but the average δ66Zn (0.29±0.03‰, 2SD) is similar to loess. δ66Zn of glacial diamictites correlate roughly negatively with CIA values, but have no correlation with Zn content, implying source heterogeneity and effect from chemical weathering. δ66Zn of A-type (0.39‰ to 0.45‰) and S-type (0.28‰ to 0.35‰) granites are both homogeneous, but the latter have systematically lighter δ66Zn. This may reflect no Zn isotopic fractionation during magmatic processes and involvement of isotopically light meta-sedimentary into the sources of S-type granites. Furthermore, δ66Zn in riverine sediments display a small variation from 0.23‰ to 0.37‰, while δ66Zn of the the shales vary from 0.14‰ to 0.53‰, which could result from a combination of processes, such as biological cycling and chemical weathering. Overall, our data suggest that incipient chemical weathering can fractionate Zn isotopes significantly, meanwhile, during this process, heavy Zn are released preferentially. The UCC is estimated to have an average δ66Zn of 0.30 ±0.03‰ (2SD) with data collected in this study, which is similar to the estimated value of Bulk Silicate Earth (0.28±0.05‰)[1] and mean dissolved riverine flux (0.33‰)[2], but distinctly lighter than the bulk composition of dissolved Zn in the ocean (0.51‰)[2]. [1] Chen et al., Zinc isotope fractionation

Sensitivity and Uncertainty Analysis of Plutonium and Cesium Isotopes in Modeling of BR3 Reactor Spent Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conant, Andrew; Erickson, Anna; Robel, Martin

Nuclear forensics has a broad task to characterize recovered nuclear or radiological material and interpret the results of investigation. One approach to isotopic characterization of nuclear material obtained from a reactor is to chemically separate and perform isotopic measurements on the sample and verify the results with modeling of the sample history, for example, operation of a nuclear reactor. The major actinide plutonium and fission product cesium are commonly measured signatures of the fuel history in a reactor core. This study investigates the uncertainty of the plutonium and cesium isotope ratios of a fuel rod discharged from a research pressurizedmore » water reactor when the location of the sample is not known a priori. A sensitivity analysis showed overpredicted values for the 240Pu/ 239Pu ratio toward the axial center of the rod and revealed a lower probability of the rod of interest (ROI) being on the periphery of the assembly. The uncertainty analysis found the relative errors due to only the rod position and boron concentration to be 17% to 36% and 7% to 15% for the 240Pu/ 239Pu and 137Cs/ 135Cs ratios, respectively. Lastly, this study provides a method for uncertainty quantification of isotope concentrations due to the location of the ROI. Similar analyses can be performed to verify future chemical and isotopic analyses.« less

Sensitivity and Uncertainty Analysis of Plutonium and Cesium Isotopes in Modeling of BR3 Reactor Spent Fuel

DOE PAGES

Conant, Andrew; Erickson, Anna; Robel, Martin; ...

2017-02-03

Nuclear forensics has a broad task to characterize recovered nuclear or radiological material and interpret the results of investigation. One approach to isotopic characterization of nuclear material obtained from a reactor is to chemically separate and perform isotopic measurements on the sample and verify the results with modeling of the sample history, for example, operation of a nuclear reactor. The major actinide plutonium and fission product cesium are commonly measured signatures of the fuel history in a reactor core. This study investigates the uncertainty of the plutonium and cesium isotope ratios of a fuel rod discharged from a research pressurizedmore » water reactor when the location of the sample is not known a priori. A sensitivity analysis showed overpredicted values for the 240Pu/ 239Pu ratio toward the axial center of the rod and revealed a lower probability of the rod of interest (ROI) being on the periphery of the assembly. The uncertainty analysis found the relative errors due to only the rod position and boron concentration to be 17% to 36% and 7% to 15% for the 240Pu/ 239Pu and 137Cs/ 135Cs ratios, respectively. Lastly, this study provides a method for uncertainty quantification of isotope concentrations due to the location of the ROI. Similar analyses can be performed to verify future chemical and isotopic analyses.« less

Preserving Plutonium-244 as a National Asset

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patton, Bradley D; Alexander, Charles W; Benker, Dennis

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.more » 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

Zinc Isotopic Compositions of Spinel Peridotites

NASA Astrophysics Data System (ADS)

Chen, S.; Huang, F.

2015-12-01

Zn isotope geochemistry has shown great potential in exploring planetary differentiation and volatilization history [1,2,3,4]. However, the zinc isotopic composition of the mantle and its fractionation mechanism in high-temperature processes are still unclear. In order to understand Zn isotope composition of the mantle, here we measured Zn isotope data for mantle rocks and minerals, including coexisting olivine, orthopyroxene (Opx), clinopyroxene (Cpx) and spinel from peridotite xenoliths in the Hannuoba (China), Vitim (Siberia), Tariat (central Mongolia), and Dariganga (SE Mongolia). As an accessary mineral, spinels in our study have high Zn contents (500-1400 ppm), accounting for 18%-40% of the total Zn budget in peridotites. Spinels have higher δ66Zn ranging from 0.17 to 0.30‰ than other mantle minerals. For most samples, the δ66Zn of olivines vary from -0.03‰ to 0.19‰, indistinguishable to the value of the coexisting Opx (0.05‰ to 0.20‰). However, we also observed large fractionation between these two minerals, which may reflect disequilibrium fractionation due to kinetic processes. Finally, δ66Zn for peridotites are 0.12-0.21‰, slightly lighter than that of basalts (~0.25±0.05‰), revealing that Zn isotopes can be slightly fractionated during mantle melting. [1] Luck et al., (2005) Geochimica Cosmo Acta, 69, 5351-5363. [2] Paniello et al., (2012) Nature, 490, 376-379. [3] Chen et al., (2013) Meteoritics Planet Sci, 48, 2441-2450. [4] Day and Moynier, (2014) Phil. Transac. of the Royal Society B, 372, 20130259

Analysis of plutonium isotope ratios including 238Pu/239Pu in individual U-Pu mixed oxide particles by means of a combination of alpha spectrometry and ICP-MS.

PubMed

Esaka, Fumitaka; Yasuda, Kenichiro; Suzuki, Daisuke; Miyamoto, Yutaka; Magara, Masaaki

2017-04-01

Isotope ratio analysis of individual uranium-plutonium (U-Pu) mixed oxide particles contained within environmental samples taken from nuclear facilities is proving to be increasingly important in the field of nuclear safeguards. However, isobaric interferences, such as 238 U with 238 Pu and 241 Am with 241 Pu, make it difficult to determine plutonium isotope ratios in mass spectrometric measurements. In the present study, the isotope ratios of 238 Pu/ 239 Pu, 240 Pu/ 239 Pu, 241 Pu/ 239 Pu, and 242 Pu/ 239 Pu were measured for individual Pu and U-Pu mixed oxide particles by a combination of alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). As a consequence, we were able to determine the 240 Pu/ 239 Pu, 241 Pu/ 239 Pu, and 242 Pu/ 239 Pu isotope ratios with ICP-MS after particle dissolution and chemical separation of plutonium with UTEVA resins. Furthermore, 238 Pu/ 239 Pu isotope ratios were able to be calculated by using both the 238 Pu/( 239 Pu+ 240 Pu) activity ratios that had been measured through alpha spectrometry and the 240 Pu/ 239 Pu isotope ratios determined through ICP-MS. Therefore, the combined use of alpha spectrometry and ICP-MS is useful in determining plutonium isotope ratios, including 238 Pu/ 239 Pu, in individual U-Pu mixed oxide particles. Copyright © 2016 Elsevier B.V. All rights reserved.

EPA Method: Rapid Radiochemical Method for Americium-241, Radium-226, Plutonium-238/-239, Radiostronium, and Isotopic Uranium in Water for Environmental Restoration Following Homeland Security Events

EPA Pesticide Factsheets

SAM lists this method for the qualitative determination of Americium-241, Radium-226, Plutonium-238, Plutonium-239 and isotopic uranium in drinking water samples using alpha spectrometry and radiostrontium using beta counting.

Zinc isotope fractionation during magmatic differentiation and the isotopic composition of the bulk Earth

USGS Publications Warehouse

Chen, Heng; Savage, Paul S.; Teng, Fang-Zehn; Helz, Rosalind T.; Moynier, Frédéric

2013-01-01

he zinc stable isotope system has been successfully applied to many and varied fields in geochemistry, but to date it is still not completely clear how this isotope system is affected by igneous processes. In order to evaluate the potential application of Zn isotopes as a proxy for planetary differentiation and volatile history, it is important to constrain the magnitude of Zn isotopic fractionation induced by magmatic differentiation. In this study we present high-precision Zn isotope analyses of two sets of chemically diverse, cogenetic samples from Kilauea Iki lava lake, Hawaii, and Hekla volcano, Iceland, which both show clear evidence of having undergone variable and significant degrees of magmatic differentiation. The Kilauea Iki samples display small but resolvable variations in Zn isotope composition (0.26‰66Zn66Zn defined as the per mille deviation of a sample's 66Zn/64Zn compositional ratio from the JMC-Lyon standard), with the most differentiated lithologies exhibiting more positive δ66Zn values. This fractionation is likely a result of the crystallization of olivine and/or Fe–Ti oxides, which can both host Zn in their crystal structures. Samples from Hekla have a similar range of isotopic variation (0.22‰66Zn66Zn=0.28±0.05‰ (2s.d.).

Multisample conversion of water to hydrogen by zinc for stable isotope determination

USGS Publications Warehouse

Kendall, C.; Coplen, T.B.

1985-01-01

Two techniques for the conversion of water to hydrogen for stable isotope ratio determination have been developed that are especially suited for automated multisample analysis. Both procedures involve reaction of zinc shot with a water sample at 450 ??C. in one method designed for water samples in bottles, the water is put in capillaries and is reduced by zinc in reaction vessels; overall savings in sample preparation labor of 75% have been realized over the standard uranium reduction technique. The second technique is for waters evolved under vacuum and is a sealed-tube method employing 9 mm o.d. quartz tubing. Problems inherent with zinc reduction include surface inhomogeneity of the zinc and exchange of hydrogen both with the zinc and with the glass walls of the vessels. For best results, water/zinc and water/glass surface area ratios of vessels should be kept as large as possible.

Plutonium in the arctic marine environment--a short review.

PubMed

Skipperud, Lindis

2004-06-18

Anthropogenic plutonium has been introduced into the environment over the past 50 years as the result of the detonation of nuclear weapons and operational releases from the nuclear industry. In the Arctic environment, the main source of plutonium is from atmospheric weapons testing, which has resulted in a relatively uniform, underlying global distribution of plutonium. Previous studies of plutonium in the Kara Sea have shown that, at certain sites, other releases have given rise to enhanced local concentrations. Since different plutonium sources are characterised by distinctive plutonium-isotope ratios, evidence of a localised influence can be supported by clear perturbations in the plutonium-isotope ratio fingerprints as compared to the known ratio in global fallout. In Kara Sea sites, such perturbations have been observed as a result of underwater weapons tests at Chernaya Bay, dumped radioactive waste in Novaya Zemlya, and terrestrial runoff from the Ob and Yenisey Rivers. Measurement of the plutonium-isotope ratios offers both a means of identifying the origin of radionuclide contamination and the influence of the various nuclear installations on inputs to the Arctic, as well as a potential method for following the movement of water and sediment loads in the rivers.

Plutonium Story

DOE R&D Accomplishments Database

Seaborg, G. T.

1981-09-01

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

Enclosure from DOE letter dated 7/20/07 - Table 5-2, Isotopic Compositions of Rocky Flats Plutonium and Uranium

EPA Pesticide Factsheets

This enclosure from a DOE letter to EPA regarding a waste container disposed at the WIPP from the Advanced Mixed Waste Treatment Project includes Table 5-2, Isotopic Compositions of Rocky Flats Plutonium and Uranium.

An MS-DOS-based program for analyzing plutonium gamma-ray spectra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruhter, W.D.; Buckley, W.M.

1989-09-07

A plutonium gamma-ray analysis system that operates on MS-DOS-based computers has been developed for the International Atomic Energy Agency (IAEA) to perform in-field analysis of plutonium gamma-ray spectra for plutonium isotopics. The program titled IAEAPU consists of three separate applications: a data-transfer application for transferring spectral data from a CICERO multichannel analyzer to a binary data file, a data-analysis application to analyze plutonium gamma-ray spectra, for plutonium isotopic ratios and weight percents of total plutonium, and a data-quality assurance application to check spectral data for proper data-acquisition setup and performance. Volume 3 contains the software listings for these applications.

Determination of Plutonium Isotope Ratios at Very Low Levels by ICP-MS using On-Line Electrochemically Modulated Separations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liezers, Martin; Lehn, Scott A; Olsen, Khris B

2009-10-01

Electrochemically modulated separations (EMS) are shown to be a rapid and selective means of extracting and concentrating Pu from complex solutions prior to isotopic analysis by inductively coupled plasma mass spectrometry (ICP-MS). This separation is performed in a flow injection mode, on-line with the ICP-MS. A three-electrode, flow-by electrochemical cell is used to accumulate Pu at an anodized glassy carbon electrode by redox conversion of Pu(III) to Pu (IV&VI). The entire process takes place in 2% v/v (0.46M) HNO 3. No redox chemicals or acid concentration changes are required. Plutonium accumulation and release is redox dependent and controlled by themore » applied cell potential. Thus large transient volumetric concentration enhancements can be achieved. Based on more negative U(IV) potentials relative to Pu(IV), separation of Pu from uranium is efficient, thereby eliminating uranium hydride interferences. EMS-ICP-MS isotope ratio measurement performance will be presented for femtogram to attogram level plutonium concentrations.« less

Conformational effect of dicyclo-hexano-18-crown-6 on isotopic fractionation of zinc: DFT approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boda, A.; Singha Deb, A. K.; Ali, Sk. M.

2014-04-24

Generalized gradient approximated BP86 density functional employing triple zeta valence plus polarization (TZVP) basis set has been used to compute the reduced partition function ratio and isotopic separation factor for zinc isotopes. The isotopic separation factor was found to be in good agreement with the experimental results. The isotopic separation factor was found to depend on the conformation of the crown ether ligand. The trans-trans conformation shows the highest fractionation compared to cis-cis conformer. The present theoretical results can thus be used to plan the isotope separation experiments.

The zinc stable isotope signature of waste rock drainage in Arctic Canada

NASA Astrophysics Data System (ADS)

Matthies, Romy; Blowes, David

2014-05-01

Leachate emerging from a pilot-scale waste rock pile of the Diavik diamond mine, Northwest Territories, was monitored. The well-characterized waste rock consists of granite, pegmatitic granite and biotite schist with an average total sulfur and carbonate carbon concentration of 0.053 and 0.027 wt. %, respectively. During the field seasons of 2011 and 2012, the Zn stable isotope footprint was characterized alongside standard monitoring parameters. pH ranged between 4.3 and 6.8 and carbonate alkalinity was low or undetectable. Al and Fe concentrations averaged 6.78 mg L-1 and 175 µg L-1, respectively. The pH and metal mobility were governed by sulfide oxidation and sorption and co-precipitation onto iron and aluminium hydroxides. The main processes controlling zinc mobility in the range of 0.4 and 4.7 mg L-1 was the oxidative dissolution of sphalerite (ZnS) in the biotite schist and the attenuation of zinc onto secondary iron and aluminium hydroxides and desorption upon the pH declining below the pHpzc. The isotope ratios between -0.16 and +0.19 ‰ (δ66Zn, avg = +0.05 ‰, n = 43) are consistent with values reported from other sphalerite containing deposits. Zn isotope ratios and concentrations were largely uncorrelated suggesting that the processes affecting Zn mobility had little or no impact on the Zn isotope signature. Data indicate, that the Zn isotope ratios of the waste rock leachate may be used as a fingerprint to track anthropogenic, mine-derived Zn sources under varying environmental conditions.

Multi-isotopic determination of plutonium (239Pu, 240Pu, 241Pu and 242Pu) in marine sediments using sector-field inductively coupled plasma mass spectrometry.

PubMed

Donard, O F X; Bruneau, F; Moldovan, M; Garraud, H; Epov, V N; Boust, D

2007-03-28

Among the transuranic elements present in the environment, plutonium isotopes are mainly attached to particles, and therefore they present a great interest for the study and modelling of particle transport in the marine environment. Except in the close vicinity of industrial sources, plutonium concentration in marine sediments is very low (from 10(-4) ng kg(-1) for (241)Pu to 10 ng kg(-1) for (239)Pu), and therefore the measurement of (238)Pu, (239)Pu, (240)Pu, (241)Pu and (242)Pu in sediments at such concentration level requires the use of very sensitive techniques. Moreover, sediment matrix contains huge amounts of mineral species, uranium and organic substances that must be removed before the determination of plutonium isotopes. Hence, an efficient sample preparation step is necessary prior to analysis. Within this work, a chemical procedure for the extraction, purification and pre-concentration of plutonium from marine sediments prior to sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) analysis has been optimized. The analytical method developed yields a pre-concentrated solution of plutonium from which (238)U and (241)Am have been removed, and which is suitable for the direct and simultaneous measurement of (239)Pu, (240)Pu, (241)Pu and (242)Pu by SF-ICP-MS.

Isotopic variations of dissolved copper and zinc in stream waters affected by historical mining

USGS Publications Warehouse

Borrok, D.M.; Nimick, D.A.; Wanty, R.B.; Ridley, W.I.

2008-01-01

Zinc and Cu play important roles in the biogeochemistry of natural systems, and it is likely that these interactions result in mass-dependent fractionations of their stable isotopes. In this study, we examine the relative abundances of dissolved Zn and Cu isotopes in a variety of stream waters draining six historical mining districts located in the United States and Europe. Our goals were to (1) determine whether streams from different geologic settings have unique or similar Zn and Cu isotopic signatures and (2) to determine whether Zn and Cu isotopic signatures change in response to changes in dissolved metal concentrations over well-defined diel (24-h) cycles. Average ??66Zn and ??65Cu values for streams varied from +0.02??? to +0.46??? and -0.7??? to +1.4???, respectively, demonstrating that Zn and Cu isotopes are heterogeneous among the measured streams. Zinc or Cu isotopic changes were not detected within the resolution of our measurements over diel cycles for most streams. However, diel changes in Zn isotopes were recorded in one stream where the fluctuations of dissolved Zn were the largest. We calculate an apparent separation factor of ???0.3??? (66/64Zn) between the dissolved and solid Zn reservoirs in this stream with the solid taking up the lighter Zn isotope. The preference of the lighter isotope in the solid reservoir may reflect metabolic uptake of Zn by microorganisms. Additional field investigations must evaluate the contributions of soils, rocks, minerals, and anthropogenic components to Cu and Zn isotopic fluxes in natural waters. Moreover, rigorous experimental work is necessary to quantify fractionation factors for the biogeochemical reactions that are likely to impact Cu and Zn isotopes in hydrologic systems. This initial investigation of Cu and Zn isotopes in stream waters suggests that these isotopes may be powerful tools for probing biogeochemical processes in surface waters on a variety of temporal and spatial scales.

High-Precision Plutonium Isotopic Compositions Measured on Los Alamos National Laboratory’s General’s Tanks Samples: Bearing on Model Ages, Reactor Modelling, and Sources of Material. Further Discussion of Chronometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spencer, Khalil J.; Rim, Jung Ho; Porterfield, Donivan R.

2015-06-29

In this study, we re-analyzed late-1940’s, Manhattan Project era Plutonium-rich sludge samples recovered from the ''General’s Tanks'' located within the nation’s oldest Plutonium processing facility, Technical Area 21. These samples were initially characterized by lower accuracy, and lower precision mass spectrometric techniques. We report here information that was previously not discernable: the two tanks contain isotopically distinct Pu not only for the major (i.e., 240Pu, 239Pu) but trace ( 238Pu , 241Pu, 242Pu) isotopes. Revised isotopics slightly changed the calculated 241Am- 241Pu model ages and interpretations.

Interaction between zinc and freshwater and marine diatom species: Surface complexation and Zn isotope fractionation

NASA Astrophysics Data System (ADS)

Gélabert, A.; Pokrovsky, O. S.; Viers, J.; Schott, J.; Boudou, A.; Feurtet-Mazel, A.

2006-02-01

This work is devoted to characterization of zinc interaction in aqueous solution with two marine planktonic ( Thalassiosira weissflogii = TW, Skeletonema costatum = SC) and two freshwater periphytic species ( Achnanthidium minutissimum = AMIN, Navicula minima = NMIN) by combining adsorption and electrophoretic measurements with surface complexation modeling and by assessing Zn isotopes fractionation during both long term uptake and short term adsorption on diatom cells and their frustules. Reversible adsorption experiments were performed at 25 and 5 °C as a function of exposure time (5 min to 140 h), pH (2 to 10), zinc concentration in solution (10 nM to 1 mM), ionic strength ( I = 0.001 to 1.0 M) and the presence of light. While the shape of pH-dependent adsorption edge is almost the same for all four species, the constant-pH adsorption isotherm and maximal Zn binding capacities differ by an order of magnitude. The extent of adsorption increases with temperature from 5 to 25 °C and does not depend on light intensity. Zinc adsorption decreases with increase of ionic strength suggesting competition with sodium for surface sites. Cell number-normalized concentrations of sorbed zinc on whole cells and their silica frustules demonstrated only weak contribution of the latter (10-20%) to overall zinc binding by diatom cell wall. Measurements of electrophoretic mobilities ( μ) revealed negative diatoms surface potential in the full range of zinc concentrations investigated (0.15-760 μmol/L), however, the absolute value of μ decreases at [Zn] > 15 μmol/L suggesting a change in surface speciation. These observations allowed us to construct a surface complexation model for Zn binding by diatom surfaces that postulates the constant capacitance of the electric double layer and considers Zn complexation with carboxylate and silanol groups. Thermodynamic and structural parameters of this model are based on previous acid-base titration and spectroscopic results and allow

Determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using radiochemical separation combined with radiometric and mass spectrometric measurements.

PubMed

Xu, Yihong; Qiao, Jixin; Hou, Xiaolin; Pan, Shaoming; Roos, Per

2014-02-01

This paper reports an analytical method for the determination of plutonium isotopes ((238)Pu, (239)Pu, (240)Pu, (241)Pu) in environmental samples using anion exchange chromatography in combination with extraction chromatography for chemical separation of Pu. Both radiometric methods (liquid scintillation counting and alpha spectrometry) and inductively coupled plasma mass spectrometry (ICP-MS) were applied for the measurement of plutonium isotopes. The decontamination factors for uranium were significantly improved up to 7.5 × 10(5) for 20 g soil compared to the level reported in the literature, this is critical for the measurement of plutonium isotopes using mass spectrometric technique. Although the chemical yield of Pu in the entire procedure is about 55%, the analytical results of IAEA soil 6 and IAEA-367 in this work are in a good agreement with the values reported in the literature or reference values, revealing that the developed method for plutonium determination in environmental samples is reliable. The measurement results of (239+240)Pu by alpha spectrometry agreed very well with the sum of (239)Pu and (240)Pu measured by ICP-MS. ICP-MS can not only measure (239)Pu and (240)Pu separately but also (241)Pu. However, it is impossible to measure (238)Pu using ICP-MS in environmental samples even a decontamination factor as high as 10(6) for uranium was obtained by chemical separation. © 2013 Elsevier B.V. All rights reserved.

Sources of plutonium in the atmosphere and stratosphere-troposphere mixing

PubMed Central

Hirose, Katsumi; Povinec, Pavel P.

2015-01-01

Plutonium isotopes have primarily been injected to the stratosphere by the atmospheric nuclear weapon tests and the burn-up of the SNAP-9A satellite. Here we show by using published data that the stratospheric plutonium exponentially decreased with apparent residence time of 1.5 ± 0.5 years, and that the temporal variations of plutonium in surface air followed the stratospheric trends until the early 1980s. In the 2000s, plutonium and its isotope ratios in the atmosphere varied dynamically, and sporadic high concentrations of 239,240Pu reported for the lower stratospheric and upper tropospheric aerosols may be due to environmental events such as the global dust outbreaks and biomass burning. PMID:26508010

Plutonium in the atmosphere: A global perspective.

PubMed

Thakur, P; Khaing, H; Salminen-Paatero, S

2017-09-01

A number of potential source terms have contributed plutonium isotopes to the atmosphere. The atmospheric nuclear weapon tests conducted between 1945 and 1980 and the re-entry of the burned SNAP-9A satellite in 1964, respectively. It is generally believed that current levels of plutonium in the stratosphere are negligible and compared with the levels generally found at surface-level air. In this study, the time trend analysis and long-term behavior of plutonium isotopes ( 239+240 Pu and 238 Pu) in the atmosphere were assessed using historical data collected by various national and international monitoring networks since 1960s. An analysis of historical data indicates that 239+240 Pu concentration post-1984 is still frequently detectable, whereas 238 Pu is detected infrequently. Furthermore, the seasonal and time-trend variation of plutonium concentration in surface air followed the stratospheric trends until the early 1980s. After the last Chinese test of 1980, the plutonium concentrations in surface air dropped to the current levels, suggesting that the observed concentrations post-1984 have not been under stratospheric control, but rather reflect the environmental processes such as resuspension. Recent plutonium atmospheric air concentrations data show that besides resuspension, other environmental processes such as global dust storms and biomass burning/wildfire also play an important role in redistributing plutonium in the atmosphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

Utilization of non-weapons-grade plutonium and highly enriched uranium with breeding of the 233U isotope in the VVER reactors using thorium and heavy water

NASA Astrophysics Data System (ADS)

Marshalkin, V. E.; Povyshev, V. M.

2015-12-01

A method for joint utilization of non-weapons-grade plutonium and highly enriched uranium in the thorium-uranium—plutonium oxide fuel of a water-moderated reactor with a varying water composition (D2O, H2O) is proposed. The method is characterized by efficient breeding of the 233U isotope and safe reactor operation and is comparatively simple to implement.

Zinc Isotopes as Tracers of Crust-Mantle Interactions and Mineralization Processes in Layered Intrusions

NASA Astrophysics Data System (ADS)

Day, J. M.; Moynier, F.

2016-12-01

Zinc isotopes are a powerful tool for studying igneous processes and may be useful for distinguishing between mantle or crustal origins for mineralization and for examining crystallization processes. Restricted ranges in δ66Zn for mantle-derived rocks (δ66Zn = 0.28±0.05‰; [{66Zn/64Znsample/66Zn/64ZnJMC-Lyon-1} × 1000] all uncertainties reported are 2SD) contrast the large δ66Zn variations in sedimentary rocks ( 0 to 1‰), or in volcanic and sedimentary hosted ore deposits (e.g., SEDEX; VHMS; MVT = -0.6 to 1.3‰). Here, we use Zn isotopes to investigate magmatic processes in the 1.27 Ga Muskox Intrusion (Canada) and 2.7 Ga Stillwater Intrusion (Montana). The Muskox main chromitite horizon has between 270-330 ppm Zn with δ66Zn ranging from 0.16 to 0.31‰. Zinc isotope compositions negatively correlate with Os isotopes. Chromitite (40a) with the lowest 187Os/188Os (0.132) has δ66Zn of 0.31±0.03‰; indistinguishable from the mantle value. CM19 glass from the co-eval Coppermine Volcanics, which has crust-like O and Nd isotopes but low 187Os/188Os (0.131), has been interpreted as the extrusive manifestation of chromitite genesis. The value of δ66Zn (0.27±0.07‰) for CM19 is within uncertainty of 40A, and permissive of formation during silicic-mafic melt mixing and large-scale chromitite crystallization. Stillwater chromitite seams exhibit a larger range in Zn (166-448 ppm), but generally lower δ66Zn (0.13±0.04‰) than Muskox chromitites, or to a JM Reef bulk sample (69 ppm Zn, δ66Zn = 0.22±0.03‰). These results suggest different sources of Zn for Ultramafic series chromitites versus the JM Reef (Banded series). Correspondingly, variations occur in Os isotopes for PGE poor chromitites (γOs = -2 to +4) versus the PGE-rich JM Reef (γOs = +12 to +34). Zinc isotope variations may be explained by either a mantle source with low δ66Zn that was subsequently contaminated by high δ66Zn crust, or from contamination of the ultramafic series by low δ66Zn

Trace determination of zinc by substoichiometric isotope dilution analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandhya, D.; Priya, S.; Subramanian, M.O.S.

1996-09-01

A radiometric method based on substoichiometric isotope dilution analysis using 1,10-phenanthroline and a substoichiometric amount of eosin was developed for determining trace amounts of zinc. Evaluation of various metal ion interferences shows that as little as 0.2 {mu}g Zn could be determined in an aqueous-phase volume of 60 mL. The method has been successfully applied to the determination of Zn in city waste incineration ash, cadmium metal, Fourts-B tablets, Boro-plus ointment, and magnesium alloy samples. 12 refs., 3 figs., 3 tabs.

Zinc isotope systematics of subduction-zone magmas

NASA Astrophysics Data System (ADS)

Huang, J.; Zhang, X. C.; Huang, F.; Yu, H.

2016-12-01

Subduction-zone magmas are generated by partial melting of mantle wedge triggered by addition of fluids derived from subducted hydrothermally altered oceanic lithosphere. Source of the fluids may be sediment, altered oceanic crust and serpentinized peridotite/serpentinite. Knowledge of the exact fluid source can facilitate our better understanding of the mechanism of fluid flux, element cycling and crust-mantle interaction in subduction zones. Zinc isotopes have the potential to place a constraint on this issue, because (1) Zn has an intermediate mobility during fluid-rock interaction and is enriched in subduction-zone fluids (e.g., Li et al., 2013); (2) sediment, altered oceanic crust and serpentinite have distinct Zn isotopic compositions (Pons et al., 2011); and (3) the mantle has a homogeneous Zn isotope composition (δ66Zn = 0.28 ± 0.05‰, Chen et al., 2013). Thus, the Zn isotopic composition of subduction-zone magmas reflects the characteristics of slab-derived fluids of different sources. Here, high-precision Zn isotope analyses were conducted on igneous rocks from arcs of Central America, Kamchatka, South Lesser Antilles, and Aleutian. One rhyolite with 75.1 wt.% SiO2 and 0.2 wt.% FeOT displays the heaviest δ66Zn value of 0.394‰ (relative to JMC Lyon) that probably results from the crystallization of Fe-Ti oxides during the late-stage differentiation. The rest of rocks have Zn isotopic compositions (0.161 to 0.339‰) similar to or lighter than those of the mantle. In an individual arc, the δ66Zn values of rocks show broad negative correlations with Ba/Th and 87Sr/86Sr ratios, suggesting that the slab-derived fluids should have lighter δ66Zn as well as higher Ba/Th and 87Sr/86Sr ratios relative to the mantle. These features are in accordance with those of serpentinites. Thus, addition of serpentinite-derived 66Zn-depleted fluids into the mantle wedge can explain the declined δ66Zn of subduction-zone magmas. ReferenceChen et al. (2013) EPSL 369

Copper and Zinc isotope composition of CR, CB and CH-like meteorites.

NASA Astrophysics Data System (ADS)

Russell, S.; Zhu, X.; Guo, Y.; Mullane, E.; Gounelle, M.; Mason, T.; Coles, B.

2003-04-01

Copper and zinc isotopes have recently been shown to be variable in isotopic composi-tion among terrestrial and extraterrestrial materials [1-3]. For this study, we have se-lected samples (bulk meteorite and chondrule separates) from the CR meteorite clan: Bencubbin (CB), Renazzo (CR2), NWA 801 (CR2), and HaH237 (CH-like). These meteorites were selected because meteorites from this clan have experienced very little alteration since their initial formation [4] and for their extremely high refrac-tory/volatile element ratios. The latter characteristic may allow a test of the correlation observed by [2] between element ratios and Cu isotope composition. Measurements were performed on NHM/IC Micromass Isoprobe and Oxford Nu MC-ICP-MS using techniques described elsewhere [1,5]. Each of the meteorites measured so far for Cu and Zn are isotopically light compared to the terrestrial mantle. This suggests that the terrestrial value may have been altered from the pristine solar system value, or else there were multiple early solar system components. Zinc isotopic com-positions lie on a fractionation line and range from δ66ZnNIST = -1.4±0.1ppm (bulk NWA801) to -1.9±0.1ppm (separated chondrule, NWA 801). Copper isotope compositions vary from δ65CuNIST976 = -1.5±0.1ppm (bulk Renazzo) to -3.1±0.1ppm (separated chondrule, NWA 801). Two chondrules from NWA 801 have differing Cu isotope values (-3.1±0.1 and -2.0±0.1ppm) and both are lighter than the bulk meteorite (-1.9±0.1ppm), suggesting a lack of equilibration with respect to Cu in this meteorite. The light values for the two separated chondrules, compared the bulk meteorite, hints that chondrules may be isotopically lighter than co-existing matrix, metal and sulphides with respect to Cu. The copper isotope compositions are not as isotopically light as expected for the high refractory/volatile element ratio observed in these chondrites. Thus a model to account for the Cu isotopes in chondrites may require greater com

Cadmium and zinc isotopes of organic-rich marine sediments during Oceanic Anoxic Event 2

NASA Astrophysics Data System (ADS)

Sweere, T.; Dickson, A. J.; Jenkyns, H. C.; Porcelli, D.; Henderson, G. M.; van den Boorn, S.

2017-12-01

Mesozoic Oceanic Anoxic Events (OAEs) are characterized by widespread deposition of organic-rich sediments and the spread of low-oxygen marine environments. To drive and sustain unusually efficient carbon-burial during these events requires high export productivity rates, which has to be supported by an abundance of nutrients in the surface ocean. The presence of redox-sensitive bio-essential micronutrients may be particularly important, and potentially bio-limiting, during such events as they may be drawn down into sediment under low-oxygen conditions. Cadmium and zinc isotopes have potential as tracers for past (micro)nutrient dynamics considering their nutrient-like distribution in the modern ocean and isotope fractionation with uptake by primary producers. The modern deep ocean is generally well mixed for Cd and Zn while short-term cycling of these elements in the surface ocean imposes regional variation. Additional regional variation may be caused by sulfide formation and associated isotope fractionation in euxinic environments. The impact of such regional environmental conditions on the Cd- and Zn-isotope composition of the sediment therefore needs to be addressed in order to explore the use of these elements as a proxy for past nutrient conditions. Here we present an extensive dataset of cadmium- and zinc-isotope compositions of organic-rich marine sediments from different basins deposited during OAE 2 (Late Cretaceous). This comparison highlights regional differences in Cd- and Zn-isotope compositions. However, despite regional environmental controls, a correlation between δ114Cd and δ66Zn across the different sites is observed, which implies a largely similar control on the two isotope systems. When regional environmental controls are accounted for, the data may provide insight in the δ66Zn and δ114Cd evolution of global seawater during OAE 2 as well as information on the global cycling of redox-sensitive micronutrients during the event

Silicon and Zinc Isotopes in Ocean Island Basalts

NASA Astrophysics Data System (ADS)

Pringle, E. A.; Savage, P. S.; Jackson, M. G.; Moreira, M. A.; Day, J. M.; Moynier, F.

2013-12-01

Analyses of Ocean Island Basalts (OIB) have shown that the Earth's mantle contains isotopically distinct components, but current debate about the degree and scale of compositional variability persists. Isotopic heterogeneities in OIB for both radiogenic (e.g. Sr, Nd, Pb) and stable (e.g. Li, O, Ca) isotope systems have been attributed to the presence of recycled materials in different mantle reservoirs [1]. The study of both silicon and zinc isotopes in OIB form a complimentary approach to investigate potential heterogeneities in the mantle. Both isotope systems show limited fractionation during igneous process [2,3]. However, both Si and Zn exhibit larger (>1‰) variability in low-temperature environments (e.g. as a result of chemical weathering and biological utilization). Therefore, Si and Zn isotopes may be useful as tracers for the presence of crustal material (derived from low-T surface processes) in OIB source regions. Furthermore, characterizing the isotopic composition of the mantle is of central importance to the use of these isotopic systems as a basis for interplanetary comparisons. Here we present high-precision Si and Zn isotopic data obtained by MC-ICPMS for a diverse suite of OIB representing the EM-1, EM-2, and HIMU mantle components. Samples represent locations in the Pacific, Atlantic, and Indian Oceans. Data are reported as the permil deviation (×2 sd) from NBS28 for Si (δ30Si) and JMC-Lyon for Zn (δ66Zn). Average δ30Si values for OIB from EM-1 (-0.32×0.09‰), EM-2 (-0.30×0.03‰), and HIMU (-0.34×0.12‰) are all in general agreement with previous estimates for the δ30Si value of Bulk Silicate Earth (BSE) [4]. Similarly, the δ66Zn average values for OIB from the EM-1, EM-2, and HIMU components (0.31×0.06‰, 0.31×0.04‰, 0.31×0.05‰, respectively) agree well with previously published data for the δ66Zn value of BSE [3]. At the current levels of precision, both Si and Zn isotopes exhibit little variation in OIB, confirming the

Plutonium release from Fukushima Daiichi fosters the need for more detailed investigations

NASA Astrophysics Data System (ADS)

Schneider, Stephanie; Walther, Clemens; Bister, Stefan; Schauer, Viktoria; Christl, Marcus; Synal, Hans-Arno; Shozugawa, Katsumi; Steinhauser, Georg

2013-10-01

The contamination of Japan after the Fukushima accident has been investigated mainly for volatile fission products, but only sparsely for actinides such as plutonium. Only small releases of actinides were estimated in Fukushima. Plutonium is still omnipresent in the environment from previous atmospheric nuclear weapons tests. We investigated soil and plants sampled at different hot spots in Japan, searching for reactor-borne plutonium using its isotopic ratio 240Pu/239Pu. By using accelerator mass spectrometry, we clearly demonstrated the release of Pu from the Fukushima Daiichi power plant: While most samples contained only the radionuclide signature of fallout plutonium, there is at least one vegetation sample whose isotope ratio (0.381 +/- 0.046) evidences that the Pu originates from a nuclear reactor (239+240Pu activity concentration 0.49 Bq/kg). Plutonium content and isotope ratios differ considerably even for very close sampling locations, e.g. the soil and the plants growing on it. This strong localization indicates a particulate Pu release, which is of high radiological risk if incorporated.

Nickel and zinc isotope fractionation in hyperaccumulating and nonaccumulating plants.

PubMed

Deng, Teng-Hao-Bo; Cloquet, Christophe; Tang, Ye-Tao; Sterckeman, Thibault; Echevarria, Guillaume; Estrade, Nicolas; Morel, Jean-Louis; Qiu, Rong-Liang

2014-10-21

Until now, there has been little data on the isotope fractionation of nickel (Ni) in higher plants and how this can be affected by plant Ni and zinc (Zn) homeostasis. A hydroponic cultivation was conducted to investigate the isotope fractionation of Ni and Zn during plant uptake and translocation processes. The nonaccumulator Thlaspi arvense, the Ni hyperaccumulator Alyssum murale and the Ni and Zn hyperaccumulator Noccaea caerulescens were grown in low (2 μM) and high (50 μM) Ni and Zn solutions. Results showed that plants were inclined to absorb light Ni isotopes, presumably due to the functioning of low-affinity transport systems across root cell membrane. The Ni isotope fractionation between plant and solution was greater in the hyperaccumulators grown in low Zn treatments (Δ(60)Ni(plant-solution) = -0.90 to -0.63‰) than that in the nonaccumulator T. arvense (Δ(60)Ni(plant-solution) = -0.21‰), thus indicating a greater permeability of the low-affinity transport system in hyperaccumulators. Light isotope enrichment of Zn was observed in most of the plants (Δ(66)Zn(plant-solution) = -0.23 to -0.10‰), but to a lesser extent than for Ni. The rapid uptake of Zn on the root surfaces caused concentration gradients, which induced ion diffusion in the rhizosphere and could result in light Zn isotope enrichment in the hyperaccumulator N. caerulescens. In high Zn treatment, Zn could compete with Ni during the uptake process, which reduced Ni concentration in plants and decreased the extent of Ni isotope fractionation (Δ(60)Ni(plant-solution) = -0.11 to -0.07‰), indicating that plants might take up Ni through a low-affinity transport system of Zn. We propose that isotope composition analysis for transition elements could become an empirical tool to study plant physiological processes.

Utilization of non-weapons-grade plutonium and highly enriched uranium with breeding of the {sup 233}U isotope in the VVER reactors using thorium and heavy water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marshalkin, V. E., E-mail: marshalkin@vniief.ru; Povyshev, V. M.

A method for joint utilization of non-weapons-grade plutonium and highly enriched uranium in the thorium–uranium—plutonium oxide fuel of a water-moderated reactor with a varying water composition (D{sub 2}O, H{sub 2}O) is proposed. The method is characterized by efficient breeding of the {sup 233}U isotope and safe reactor operation and is comparatively simple to implement.

Zinc isotope investigation of surface and pore waters in a mountain watershed impacted by acid rock drainage.

PubMed

Aranda, Suzan; Borrok, David M; Wanty, Richard B; Balistrieri, Laurie S

2012-03-15

The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the δ(66)Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30‰±0.09‰ 2σ). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The δ(66)Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80‰±0.09‰ 2σ. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in soil pore waters. Copyright © 2012 Elsevier B.V. All rights reserved.

Zinc isotope fractionation during mantle melting and constraints on the Zn isotope composition of Earth's upper mantle

NASA Astrophysics Data System (ADS)

Wang, Ze-Zhou; Liu, Sheng-Ao; Liu, Jingao; Huang, Jian; Xiao, Yan; Chu, Zhu-Yin; Zhao, Xin-Miao; Tang, Limei

2017-02-01

The zinc (Zn) stable isotope system has great potential for tracing planetary formation and differentiation processes due to its chalcophile, lithophile and moderately volatile character. As an initial approach, the terrestrial mantle, and by inference, the bulk silicate Earth (BSE), have previously been suggested to have an average δ66Zn value of ∼+0.28‰ (relative to JMC 3-0749L) primarily based on oceanic basalts. Nevertheless, data for mantle peridotites are relatively scarce and it remains unclear whether Zn isotopes are fractionated during mantle melting. To address this issue, we report high-precision (±0.04‰; 2SD) Zn isotope data for well-characterized peridotites (n = 47) from cratonic and orogenic settings, as well as their mineral separates. Basalts including mid-ocean ridge basalts (MORB) and ocean island basalts (OIB) were also measured to avoid inter-laboratory bias. The MORB analyzed have homogeneous δ66Zn values of +0.28 ± 0.03‰ (here and throughout the text, errors are given as 2SD), similar to those of OIB obtained in this study and in the literature (+0.31 ± 0.09‰). Excluding the metasomatized peridotites that exhibit a wide δ66Zn range of -0.44‰ to +0.42‰, the non-metasomatized peridotites have relatively uniform δ66Zn value of +0.18 ± 0.06‰, which is lighter than both MORB and OIB. This difference suggests a small but detectable Zn isotope fractionation (∼0.1‰) during mantle partial melting. The magnitude of inter-mineral fractionation between olivine and pyroxene is, on average, close to zero, but spinels are always isotopically heavier than coexisting olivines (Δ66ZnSpl-Ol = +0.12 ± 0.07‰) due to the stiffer Zn-O bonds in spinel than silicate minerals (Ol, Opx and Cpx). Zinc concentrations in spinels are 11-88 times higher than those in silicate minerals, and our modelling suggests that spinel consumption during mantle melting plays a key role in generating high Zn concentrations and heavy Zn isotopic

Improved plutonium identification and characterization results with NaI(Tl) detector using ASEDRA

NASA Astrophysics Data System (ADS)

Detwiler, R.; Sjoden, G.; Baciak, J.; LaVigne, E.

2008-04-01

The ASEDRA algorithm (Advanced Synthetically Enhanced Detector Resolution Algorithm) is a tool developed at the University of Florida to synthetically enhance the resolved photopeaks derived from a characteristically poor resolution spectra collected at room temperature from scintillator crystal-photomultiplier detector, such as a NaI(Tl) system. This work reports on analysis of a side-by-side test comparing the identification capabilities of ASEDRA applied to a NaI(Tl) detector with HPGe results for a Plutonium Beryllium (PuBe) source containing approximately 47 year old weapons-grade plutonium (WGPu), a test case of real-world interest with a complex spectra including plutonium isotopes and 241Am decay products. The analysis included a comparison of photopeaks identified and photopeak energies between the ASEDRA and HPGe detector systems, and the known energies of the plutonium isotopes. ASEDRA's performance in peak area accuracy, also important in isotope identification as well as plutonium quality and age determination, was evaluated for key energy lines by comparing the observed relative ratios of peak areas, adjusted for efficiency and attenuation due to source shielding, to the predicted ratios from known energy line branching and source isotopics. The results show that ASEDRA has identified over 20 lines also found by the HPGe and directly correlated to WGPu energies.

Lead and zinc dust depositions from ore trains characterised using lead isotopic compositions.

PubMed

Kristensen, L J; Taylor, M P; Morrison, A L

2015-03-01

This study investigates an unusual source of environmental lead contamination - the emission and deposition of lead and zinc concentrates along train lines into and out of Australia's oldest silver-lead-zinc mine at Broken Hill, Australia. Transport of lead and zinc ore concentrates from the Broken Hill mines has occurred for more than 125 years, during which time the majority was moved in uncovered rail wagons. A significant amount of ore was lost to the adjoining environments, resulting in soil immediately adjacent to train lines elevated with concentrations of lead (695 mg kg(-1)) and zinc (2230 mg kg(-1)). Concentrations of lead and zinc decreased away from the train line and also with depth shown in soil profiles. Lead isotopic compositions demonstrated the soil lead contained Broken Hill ore in increasing percentages closer to the train line, with up to 97% apportioned to the mined Broken Hill ore body. SEM examination showed ceiling dusts collected from houses along the train line were composed of unweathered galena particles, characteristic of the concentrate transported in the rail wagons. The loss of ore from the uncovered wagons has significantly extended the environmental footprint of contamination from local mining operations over an area extending hundreds of kilometres along each of the three train lines.

Critical Need for Plutonium and Uranium Isotopic Standards with Lower Uncertainties

DOE PAGES

Mathew, Kattathu Joseph; Stanley, Floyd E.; Thomas, Mariam R.; ...

2016-09-23

Certified reference materials (CRMs) traceable to national and international safeguards database are a critical prerequisite for ensuring that nuclear measurement systems are free of systematic biases. CRMs are used to validate measurement processes associated with nuclear analytical laboratories. Diverse areas related to nuclear safeguards are impacted by the quality of the CRM standards available to analytical laboratories. These include: nuclear forensics, radio-chronometry, national and international safeguards, stockpile stewardship, nuclear weapons infrastructure and nonproliferation, fuel fabrication, waste processing, radiation protection, and environmental monitoring. For the past three decades the nuclear community is confronted with the strange situation that improvements in measurementmore » data quality resulting from the improved accuracy and precision achievable with modern multi-collector mass spectrometers could not be fully exploited due to large uncertainties associated with CRMs available from New Brunswick Laboratory (NBL) that are used for instrument calibration and measurement control. Similar conditions prevail for both plutonium and uranium isotopic standards and for impurity element standards in uranium matrices. Herein, the current status of U and Pu isotopic standards available from NBL is reviewed. Critical areas requiring improvement in the quality of the nuclear standards to enable the U. S. and international safeguards community to utilize the full potential of modern multi-collector mass spectrometer instruments are highlighted.« less

Critical Need for Plutonium and Uranium Isotopic Standards with Lower Uncertainties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathew, Kattathu Joseph; Stanley, Floyd E.; Thomas, Mariam R.

Certified reference materials (CRMs) traceable to national and international safeguards database are a critical prerequisite for ensuring that nuclear measurement systems are free of systematic biases. CRMs are used to validate measurement processes associated with nuclear analytical laboratories. Diverse areas related to nuclear safeguards are impacted by the quality of the CRM standards available to analytical laboratories. These include: nuclear forensics, radio-chronometry, national and international safeguards, stockpile stewardship, nuclear weapons infrastructure and nonproliferation, fuel fabrication, waste processing, radiation protection, and environmental monitoring. For the past three decades the nuclear community is confronted with the strange situation that improvements in measurementmore » data quality resulting from the improved accuracy and precision achievable with modern multi-collector mass spectrometers could not be fully exploited due to large uncertainties associated with CRMs available from New Brunswick Laboratory (NBL) that are used for instrument calibration and measurement control. Similar conditions prevail for both plutonium and uranium isotopic standards and for impurity element standards in uranium matrices. Herein, the current status of U and Pu isotopic standards available from NBL is reviewed. Critical areas requiring improvement in the quality of the nuclear standards to enable the U. S. and international safeguards community to utilize the full potential of modern multi-collector mass spectrometer instruments are highlighted.« less

Validation of Electrochemically Modulated Separations Performed On-Line with MC-ICP-MS for Uranium and Plutonium Isotopic Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liezers, Martin; Olsen, Khris B.; Mitroshkov, Alexandre V.

2010-08-11

The most time consuming process in uranium or plutonium isotopic analyses is performing the requisite chromatographic separation of the actinides. Filament preparation for thermal ionization (TIMS) adds further delays, but is generally accepted due to the unmatched performance in trace isotopic analyses. Advances in Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) are beginning to rival the performance of TIMS. Methods, such as Electrochemically Modulated Separations (EMS) can efficiently pre-concentrate U or Pu quite selectively from small solution volumes in a matrix of 0.5 M nitric acid. When performed in-line with ICP-MS, the rapid analyte release from the electrode is fast,more » and large transient analyte signal enhancements of >100 fold can be achieved as compared to more conventional continuous nebulization of the original starting solution. This makes the approach ideal for very low level isotope ratio measurements. In this paper, some aspects of EMS performance are described. These include low level Pu isotope ratio behavior versus concentration by MC-ICP-MS and uranium rejection characteristics that are also important for reliable low level Pu isotope ratio determinations.« less

Tracking the rise of eukaryotes to ecological dominance with zinc isotopes.

PubMed

Isson, Terry T; Love, Gordon D; Dupont, Christopher L; Reinhard, Christopher T; Zumberge, Alex J; Asael, Dan; Gueguen, Bleuenn; McCrow, John; Gill, Ben C; Owens, Jeremy; Rainbird, Robert H; Rooney, Alan D; Zhao, Ming-Yu; Stueeken, Eva E; Konhauser, Kurt O; John, Seth G; Lyons, Timothy W; Planavsky, Noah J

2018-06-05

The biogeochemical cycling of zinc (Zn) is intimately coupled with organic carbon in the ocean. Based on an extensive new sedimentary Zn isotope record across Earth's history, we provide evidence for a fundamental shift in the marine Zn cycle ~800 million years ago. We discuss a wide range of potential drivers for this transition and propose that, within available constraints, a restructuring of marine ecosystems is the most parsimonious explanation for this shift. Using a global isotope mass balance approach, we show that a change in the organic Zn/C ratio is required to account for observed Zn isotope trends through time. Given the higher affinity of eukaryotes for Zn relative to prokaryotes, we suggest that a shift toward a more eukaryote-rich ecosystem could have provided a means of more efficiently sequestering organic-derived Zn. Despite the much earlier appearance of eukaryotes in the microfossil record (~1700 to 1600 million years ago), our data suggest a delayed rise to ecological prominence during the Neoproterozoic, consistent with the currently accepted organic biomarker records. © 2018 John Wiley & Sons Ltd.

Zinc isotope ratios of bones and teeth as new dietary indicators: results from a modern food web (Koobi Fora, Kenya)

NASA Astrophysics Data System (ADS)

Jaouen, Klervia; Beasley, Melanie; Schoeninger, Margaret; Hublin, Jean-Jacques; Richards, Michael P.

2016-05-01

In order to explore the possibilities of using zinc (Zn) stable isotope ratios as dietary indicators, we report here on the measurements of the ratio of stable isotopes of zinc (66Zn/64Zn, expressed here as δ66Zn) in bioapatite (bone and dental enamel) of animals from a modern food web in the Koobi Fora region of the Turkana Basin in Kenya. We demonstrate that δ66Zn values in both bone and enamel allow a clear distinction between carnivores and herbivores from this food web. Differences were also observed between browsers and grazers as well as between carnivores that consumed bone (i.e. hyenas) compared to those that largely consume flesh (i.e. lions). We conclude that Zn isotope ratio measurements of bone and teeth are a new and promising dietary indicator.

Zinc Absorption from Representative Diet in a Chinese Elderly Population Using Stable Isotope Technique.

PubMed

Li, Ya Jie; Li, Min; Liu, Xiao Bing; Ren, Tong Xiang; Li, Wei Dong; Yang, Chun; Wu, Meng; Yang, Lin Li; Ma, Yu Xia; Wang, Jun; Piao, Jian Hua; Yang, Li Chen; Yang, Xiao Guang

2017-06-01

To determine the dietary zinc absorption in a Chinese elderly population and provide the basic data for the setting of zinc (Zn) recommended nutrient intakes (RNI) for Chinese elderly people. A total of 24 elderly people were recruited for this study and were administered oral doses of 3 mg 67Zn and 1.2 mg dysprosium on the fourth day. The primary macronutrients, energy, and phytic acid in the representative diet were examined based on the Chinese National Standard Methods. Fecal samples were collected during the experimental period and analyzed for zinc content, 67Zn isotope ratio, and dysprosium content. The mean (± SD) zinc intake from the representative Chinese diet was 10.6 ± 1.5 mg/d. The phytic acid-to-zinc molar ratio in the diet was 6.4. The absorption rate of 67Zn was 27.9% ± 9.2%. The RNI of zinc, which were calculated by the absorption rate in elderly men and women, were 10.4 and 9.2 mg/d, respectively. This study got the dietary Zn absorption in a Chinese elderly population. We found that Zn absorption was higher in elderly men than in elderly women. The current RNI in elderly female is lower than our finding, which indicates that more attention is needed regarding elderly females' zinc status and health. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Zinc isotopes in sphalerite from base metal deposits in the Red Dog district, northern Alaska

USGS Publications Warehouse

Kelley, K.D.; Wilkinson, J.J.; Chapman, J.B.; Crowther, H.L.; Weiss, D.J.

2009-01-01

Analyses of sphalerite samples from shale-hosted massive sulfide and stratigraphically underlying vein breccia deposits in the Red Dog district in northern Alaska show a range ??66Zn values from zero to 0.60 per mil. The lowest values are observed in the vein breccia deposits, and the stratigraphically overlying (but structurally displaced) shale-hosted massive sulfide deposits show a systematic trend of increasing ??66Zn values from south to north (Main-Aqqaluk-Paalaaq-Anarraaq). The ??66Zn values are inversely correlated with sphalerite Fe/Mn ratio and also tend to be higher in low Cu sphalerite, consistent with precipitation of lower ??66Zn sphalerite closer to the principal hydrothermal fluid conduits. The most likely control on isotopic variation is Rayleigh fractionation during sulfide precipitation, with lighter zinc isotopes preferentially incorporated in the earliest sphalerite to precipitate from ore fluids at deeper levels (vein breccias) and close to the principal fluid conduits in the orebodies, followed by precipitation of sulfides with higher ??66Zn values in shallower and/or more distal parts of the flow path. There is no systematic variation among the paragenetic stages of sphalerite from a single deposit, suggesting an isotopically homogeneous zinc source and consistent transport-deposition conditions and/or dissolution-reprecipitation of earlier sphalerite without significant fractionation. Decoupled Zn and S isotope compositions are best explained by mixing of separate metal- and sulfur-bearing fluids at the depositional site. The results confirm that Zn isotopes may be a useful tracer for distinguishing between the central and distal parts of large hydrothermal systems as previously suggested and could therefore be of use in exploration. ?? 2009 by Economic Geology.

Stability of zinc stearate under alpha irradiation in the manufacturing process of SFR nuclear fuels

NASA Astrophysics Data System (ADS)

Gracia, J.; Vermeulen, J.; Baux, D.; Sauvage, T.; Venault, L.; Audubert, F.; Colin, X.

2018-03-01

The manufacture of new fuels for sodium-cooled fast reactors (SFRs) will involve powders derived from recycling existing fuels in order to keep on producing electricity while saving natural resources and reducing the amount of waste produced by spent MOX fuels. Using recycled plutonium in this way will significantly increase the amount of 238Pu, a high energy alpha emitter, in the powders. The process of shaping powders by pressing requires the use of a solid lubricant, zinc stearate, to produce pellets with no defects compliant with the standards. The purpose of this study is to determine the impact of alpha radiolysis on this additive and its lubrication properties. Experiments were conducted on samples in contact with PuO2, as well as under external helium ion beam irradiation, in order to define the kinetics of radiolytic gas generation. The yield results relating to the formation of these gases (G0) show that the alpha radiation of plutonium can be simulated using external helium ion beam irradiation. The isotopic composition of plutonium has little impact on the yield. However, an increased yield was globally observed with increasing the mean linear energy transfer (LET). A radiolytic degradation process is proposed.

Fission fragment mass and total kinetic energy distributions of spontaneously fissioning plutonium isotopes

NASA Astrophysics Data System (ADS)

Pomorski, K.; Nerlo-Pomorska, B.; Bartel, J.; Schmitt, C.

2018-03-01

The fission-fragment mass and total kinetic energy (TKE) distributions are evaluated in a quantum mechanical framework using elongation, mass asymmetry, neck degree of freedom as the relevant collective parameters in the Fourier shape parametrization recently developed by us. The potential energy surfaces (PES) are calculated within the macroscopic-microscopic model based on the Lublin-Strasbourg Drop (LSD), the Yukawa-folded (YF) single-particle potential and a monopole pairing force. The PES are presented and analysed in detail for even-even Plutonium isotopes with A = 236-246. They reveal deep asymmetric valleys. The fission-fragment mass and TKE distributions are obtained from the ground state of a collective Hamiltonian computed within the Born-Oppenheimer approximation, in the WKB approach by introducing a neck-dependent fission probability. The calculated mass and total kinetic energy distributions are found in good agreement with the data.

Natural Transmutation of Actinides via the Fission Reaction in the Closed Thorium-Uranium-Plutonium Fuel Cycle

NASA Astrophysics Data System (ADS)

Marshalkin, V. Ye.; Povyshev, V. M.

2017-12-01

It is shown for a closed thorium-uranium-plutonium fuel cycle that, upon processing of one metric ton of irradiated fuel after each four-year campaign, the radioactive wastes contain 54 kg of fission products, 0.8 kg of thorium, 0.10 kg of uranium isotopes, 0.005 kg of plutonium isotopes, 0.002 kg of neptunium, and "trace" amounts of americium and curium isotopes. This qualitatively simplifies the handling of high-level wastes in nuclear power engineering.

Effect of Americium-241 Content on Plutonium Radiation Source Terms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rainisch, R.

1998-12-28

The management of excess plutonium by the US Department of Energy includes a number of storage and disposition alternatives. Savannah River Site (SRS) is supporting DOE with plutonium disposition efforts, including the immobilization of certain plutonium materials in a borosilicate glass matrix. Surplus plutonium inventories slated for vitrification include materials with elevated levels of Americium-241. The Am-241 content of plutonium materials generally reflects in-growth of the isotope due to decay of plutonium and is age-dependent. However, select plutonium inventories have Am-241 levels considerably above the age-based levels. Elevated levels of americium significantly impact radiation source terms of plutonium materials andmore » will make handling of the materials more difficult. Plutonium materials are normally handled in shielded glove boxes, and the work entails both extremity and whole body exposures. This paper reports results of an SRS analysis of plutonium materials source terms vs. the Americium-241 content of the materials. Data with respect to dependence and magnitude of source terms on/vs. Am-241 levels are presented and discussed. The investigation encompasses both vitrified and un-vitrified plutonium oxide (PuO2) batches.« less

Isotopic composition of zinc, copper, and iron in lunar samples

NASA Astrophysics Data System (ADS)

Moynier, F.; Albarède, F.; Herzog, G. F.

2006-12-01

We determined by ICP-MS the concentrations and isotopic ratios of Fe, Cu, and Zn in the Ti-rich lunar basalt 74275, in the lunar orange glass 74220, and in up to 10 lunar soils, namely, 14163, 15231, 64501, 66041, 68841, 69941, 70011, 72501, 75081, and 76501. Two analyses of zinc in lunar basalt 74275 give δ 66Zn = 0.17‰ and 0.75‰, values within the range of those measured in terrestrial basalts; copper in lunar basalt 74275 has δ 65Cu ˜ +1.4‰, which is isotopically heavier than values observed in terrestrial basalts. In the orange glass, we measured δ 56Fe = -0.24‰, δ 65Cu = -0.42‰, and δ 66Zn ˜ -3.6‰. These values of δ are more negative than those obtained for 74275 and for typical lunar basalts, but for Cu, comparable to those observed in terrestrial sulfides and meteorites. In lunar soils we found 0.11‰ ⩽ δ 56Fe ⩽ 0.51‰, 2.6‰ ⩽ δ 65Cu ⩽ 4.5‰, and 2.2‰ ⩽ δ 66Zn ⩽ 6.4‰. Insofar as we can generalize from a small sample set, S, Fe, Cu, Zn, and Cd show similar trends in isotopic fractionation on the Moon. Lunar basalts have nearly terrestrial isotopic ratios. Relative to the lunar basalt 74275, the pyroclastic glass 74220 is enriched in the lighter isotopes of Fe, Cu, and Zn, and the soils are enriched in the heavier isotopes of Fe, Cu, and Zn. The patterns in the basalts are likely inherited from the source material; the light-isotope enrichments seen in the orange glass originated during lava fountaining or, less probably, during partial condensation of vapor; and the heavy-isotope enrichments in the lunar soils were likely created by a combination of processes that included micrometeorite vaporization and sputtering. In the orange glass, the light-isotope enrichments (relative to lunar basalts) of Zn are larger than those of Cu. If these enrichments reflect accurately the isotopic composition of the gas, they suggest that Cu is more volatile than Zn in the liquid from which the gas derived. A simple model built on

Zinc and sulfur isotope variation in sphalerite from carbonate-hosted zinc deposits, Cantabria, Spain

NASA Astrophysics Data System (ADS)

Pašava, Jan; Tornos, Fernando; Chrastný, Vladislav

2014-10-01

We studied zinc and sulfur isotopes and the chemical composition of sphalerite samples from Picos de Europa (Aliva mine) and sphalerite and hydrozincite samples from La Florida mine, two carbonate-hosted Mississippi Valley-type (MVT) deposits located in northern Spain; despite being close, they are hosted in carbonatic rocks of different ages, Lower Carboniferous and Lower Cretaceous, respectively. The two generations of sphalerite at Picos de Europa show different δ66Zn values (stage 1 sphalerite +0.24 per mil and stage 2 sphalerite from -0.75 to +0.08 per mil). Both generations also differ in the sulfur isotope composition (stage 1 has δ34S = +6.6 and stage 2 has δ34S = -0.9 to +2.9 per mil) and the chemical composition (stage 1 sphalerite, compared to stage 2 sphalerite, is significantly enriched in Pb, As, Mn, Sb, slightly enriched in Ag, Ni, and Cu and depleted in Co, Ga, Tl, Te, Ge, and Sn). We suggest that Zn isotope fractionation was controlled predominantly by pH and T changes. High Zn isotope values reflect rapid precipitation of sphalerite from higher-temperature acidic fluids that carried Zn mostly as chloride species after interaction with carbonate rocks while lower Zn isotope values most likely resulted from a longer precipitation process from fluid at higher pH and decreasing T that carried dominantly Zn sulfide species. At La Florida, sphalerite samples show light 66Zn-depleted signatures with δ66Zn values from -0.80 to -0.01 per mil (mostly between -0.80 and -0.24 per mil) and δ34S values from +10.7 to +15.7 per mil without any relationship between the δ66Zn and δ34S values. Here, the variation in Zn isotope values is interpreted as related to mixing of fluids from two reservoirs. The Zn was carried by a single deep-seated and higher T (~250-320 °C) fluid, and precipitation took place after mixing with a connate S-rich fluid in a system with mH2S > mZn2+ as a result of change in pH, T, and Zn predominant species. The light δ66Zn

[Rapid analysis of the radionuclides plutonium and americium-241 in soils].

PubMed

Egorov, A V; Klochkova, N V

2009-01-01

The paper shows it possible to perform a rapid analysis of the isotopes of plutomium and americium-241. The basis of the developed rapid analysis is X-spectrometric determination of the amount of plutonium isotopes and gamma-spectrometric determination of the radionuclide 241AM.

The instrumental method of plutonium determination

NASA Astrophysics Data System (ADS)

Knyazev, B. B.; Kazachevskiy, I. V.; Solodukhin, V. P.; Lukashenko, S. N.; Knatova, M. K.; Kashirskiy, V. V.

2003-01-01

A method of direct instrumental determination of plutonium isotopes in soil samples is described. For the method a special program of spectra processing and activity calculation had to be prepared. The detection limit of 239+240Pu in absence of interfering radiation is about 200 Bq/kg (by 3.3σ criteria). Examples are given of the method application for the study of radionuclide soil composition in separate objects of Semipalatinsk Nuclear Test Site (SNTS). It is shown that for different objects under study the correlation degree between plutonium and americium activities may change rather substantially.

Locating trace plutonium in contaminated soil using micro-XRF imaging

DOE PAGES

Worley, Christopher G.; Spencer, Khalil J.; Boukhalfa, Hakim; ...

2014-06-01

Micro-X-ray fluorescence (MXRF) was used to locate minute quantities of plutonium in contaminated soil. Because the specimen had previously been prepared for analysis by scanning electron microscopy, it was coated with gold to eliminate electron beam charging. However, this significantly hindered efforts to detect plutonium by MXRF. The gold L peak series present in all spectra increased background counts. Plutonium signal attenuation by the gold coating and severe peak overlap from potassium in the soil prevented detection of trace plutonium using the Pu Mα peak. However, the 14.3 keV Pu Lα peak sensitivity was not optimal due to poor transmissionmore » efficiency through the source polycapillary optic, and the instrument silicon drift detector sensitivity quickly declines for peaks with energies above ~10 keV. Instrumental parameters were optimized (eg. using appropriate source filters) in order to detect plutonium. An X-ray beam aperture was initially used to image a majority of the specimen with low spatial resolution. A small region that appeared to contain plutonium was then imaged at high spatial resolution using a polycapillary optic. Small areas containing plutonium were observed on a soil particle, and iron was co-located with the plutonium. Zinc and titanium also appeared to be correlated with the plutonium, and these elemental correlations provided useful plutonium chemical state information that helped to better understand its environmental transport properties.« less

Preparation, certification and validation of a stable solid spike of uranium and plutonium coated with a cellulose derivative for the measurement of uranium and plutonium content in dissolved nuclear fuel by isotope dilution mass spectrometry.

PubMed

Surugaya, Naoki; Hiyama, Toshiaki; Verbruggen, André; Wellum, Roger

2008-02-01

A stable solid spike for the measurement of uranium and plutonium content in nitric acid solutions of spent nuclear fuel by isotope dilution mass spectrometry has been prepared at the European Commission Institute for Reference Materials and Measurements in Belgium. The spike contains about 50 mg of uranium with a 19.838% (235)U enrichment and 2 mg of plutonium with a 97.766% (239)Pu abundance in each individual ampoule. The dried materials were covered with a thin film of cellulose acetate butyrate as a protective organic stabilizer to resist shocks encountered during transportation and to eliminate flaking-off during long-term storage. It was found that the cellulose acetate butyrate has good characteristics, maintaining a thin film for a long time, but readily dissolving on heating with nitric acid solution. The solid spike containing cellulose acetate butyrate was certified as a reference material with certified quantities: (235)U and (239)Pu amounts and uranium and plutonium amount ratios, and was validated by analyzing spent fuel dissolver solutions of the Tokai reprocessing plant in Japan. This paper describes the preparation, certification and validation of the solid spike coated with a cellulose derivative.

Age determination of single plutonium particles after chemical separation

NASA Astrophysics Data System (ADS)

Shinonaga, T.; Donohue, D.; Ciurapinski, A.; Klose, D.

2009-01-01

Age determination of single plutonium particles was demonstrated using five particles of the standard reference material, NBS 947 (Plutonium Isotopic Standard. National Bureau of Standards, Washington, D.C. 20234, August 19, 1982, currently distributed as NBL CRM-137) and the radioactive decay of 241Pu into 241Am. The elemental ratio of Am/Pu in Pu particles found on a carbon planchet was measured by wavelength dispersive X-ray spectrometry (WDX) coupled to a scanning electron microscope (SEM). After the WDX measurement, each plutonium particle, with an average size of a few μm, was picked up and relocated to a silicon wafer inside the SEM chamber using a micromanipulator. The silicon wafer was then transferred to a quartz tube for dissolution in an acid solution prior to chemical separation. After the Pu was chemically separated from Am and U, the isotopic ratios of Pu ( 240Pu/ 239Pu, 241Pu/ 239Pu and 242Pu/ 239Pu) were measured with a thermal ionization mass spectrometer (TIMS) for the calculation of Pu age. The age of particles determined in this study was in good agreement with the expected age (35.9 a) of NBS 947 within the measurement uncertainty.

Ultra-Low Level Plutonium Isotopes in the NIST SRM 4355A (Peruvian Soil-1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inn, Kenneth G.; LaRosa, Jerome; Nour, Svetlana

2009-05-31

For more than 20 years, countries and their agencies which monitor discharge sites and storage facilities have relied on the National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 4355 Peruvian Soil reference material. Its low fallout contamination makes it an ideal soil blank for measurements associated with terrestrial pathway to man studies. Presently, SRM 4355 is out of stock, and a new batch of the Peruvian soil is currently under development as future NIST SRM 4355A. Both environmental radioanalytical laboratories and mass spectrometry communities will benefit from this SRM. The former must assess their laboratory contamination andmore » measurement detection limits by measurement of blank sample material. The Peruvian Soil is so low in anthropogenic radionuclides that it is a suitable virtual blank. On the other hand, mass spectrometric laboratories have high sensitivity instruments that are capable of quantitative isotopic measurements at low plutonium levels of the SRM 4355 (first Peruvian Soil SRM) that provided the mass spectrometric community with the calibration, quality control, and testing material needed for methods development, and legal defensibility. The quantification of the ultra-low plutonium content in the SRM 4355A was a considerable challenge for the mass spectrometric laboratories. Careful blank control and correction, isobaric interferences, instrument stability, peak assessment, and detection assessment were necessary. Furthermore, a systematic statistical evaluation of the measurement results and considerable discussions with the mass spectroscopy metrologists were needed to derive the certified values and uncertainties. SRM 4355A will provide the mass spectrometric community with the quality control and testing material needed for higher sensitivity methods development, and legal defensibility.« less

Ultra-low level plutonium isotopes in the NIST SRM 4355A (Peruvian Soil-1).

PubMed

Inn, Kenneth G W; LaRosa, Jerome; Nour, Svetlana; Brooks, George; LaMont, Steve; Steiner, Rob; Williams, Ross; Patton, Brad; Bostick, Debbie; Eiden, Gregory; Petersen, Steve; Douglas, Matthew; Beals, Donna; Cadieux, James; Hall, Greg; Goldberg, Steve; Vogt, Stephan

2009-05-01

For more than 20 years, countries and their agencies which monitor radionuclide discharge sites and storage facilities have relied on the National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 4355 Peruvian Soil. Its low fallout contamination makes it an ideal soil blank for measurements associated with terrestrial-pathway-to-man studies. Presently, SRM 4355 is out of stock, and a new batch of the Peruvian soil is currently under development as future NIST SRM 4355A. Both environmental radioanalytical laboratories and mass spectrometry communities will benefit from the use of this SRM. The former must assess their laboratory procedural contamination and measurement detection limits by measurement of blank sample material. The Peruvian Soil is so low in anthropogenic radionuclide content that it is a suitable virtual blank. On the other hand, mass spectrometric laboratories have high sensitivity instruments that are capable of quantitative isotopic measurements at low plutonium levels in the SRM 4355 (first Peruvian Soil SRM) that provided the mass spectrometric community with the calibration, quality control, and testing material needed for methods development and legal defensibility. The quantification of the ultra-low plutonium content in the SRM 4355A was a considerable challenge for the mass spectrometric laboratories. Careful blank control and correction, isobaric interferences, instrument stability, peak assessment, and detection assessment were necessary. Furthermore, a systematic statistical evaluation of the measurement results and considerable discussions with the mass spectroscopy metrologists were needed to derive the certified values and uncertainties. The one sided upper limit of the 95% tolerance with 95% confidence for the massic (239)Pu content in SRM 4355A is estimated to be 54,000 atoms/g.

Zn/Cd ratios and cadmium isotope evidence for the classification of lead-zinc deposits

PubMed Central

Wen, Hanjie; Zhu, Chuanwei; Zhang, Yuxu; Cloquet, Christophe; Fan, Haifeng; Fu, Shaohong

2016-01-01

Lead-zinc deposits are often difficult to classify because clear criteria are lacking. In recent years, new tools, such as Cd and Zn isotopes, have been used to better understand the ore-formation processes and to classify Pb-Zn deposits. Herein, we investigate Cd concentrations, Cd isotope systematics and Zn/Cd ratios in sphalerite from nine Pb-Zn deposits divided into high-temperature systems (e.g., porphyry), low-temperature systems (e.g., Mississippi Valley type [MVT]) and exhalative systems (e.g., sedimentary exhalative [SEDEX]). Our results showed little evidence of fractionation in the high-temperature systems. In the low-temperature systems, Cd concentrations were the highest, but were also highly variable, a result consistent with the higher fractionation of Cd at low temperatures. The δ114/110Cd values in low-temperature systems were enriched in heavier isotopes (mean of 0.32 ± 0.31‰). Exhalative systems had the lowest Cd concentrations, with a mean δ114/110Cd value of 0.12 ± 0.50‰. We thus conclude that different ore-formation systems result in different characteristic Cd concentrations and fraction levels and that low-temperature processes lead to the most significant fractionation of Cd. Therefore, Cd distribution and isotopic studies can support better understanding of the geochemistry of ore-formation processes and the classification of Pb-Zn deposits. PMID:27121538

SEPARATION OF URANIUM, PLUTONIUM AND FISSION PRODUCTS FROM NEUTRON- BOMBARDED URANIUM

DOEpatents

Martin, A.E.; Johnson, I.; Burris, L. Jr.; Winsch, I.O.; Feder, H.M.

1962-11-13

A process is given for removing plutonium and/or fission products from uranium fuel. The fuel is dissolved in molten zinc--magnesium (10 to 18% Mg) alloy, more magnesium is added to obtain eutectic composition whereby uranium precipitates, and the uranium are separated from the Plutoniumand fission-product- containing eutectic. (AEC)

Zinc Absorption by Young Adults from Supplemental Zinc Citrate Is Comparable with That from Zinc Gluconate and Higher than from Zinc Oxide123

PubMed Central

Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnić, Marica; Hurrell, Richard F.

2014-01-01

The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67Zn and 70Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6–71.0) and was not different from that from zinc gluconate with 60.9% (50.6–71.7). Absorption from zinc oxide at 49.9% (40.9–57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627. PMID:24259556

Analysis on Reactor Criticality Condition and Fuel Conversion Capability Based on Different Loaded Plutonium Composition in FBR Core

NASA Astrophysics Data System (ADS)

Permana, Sidik; Saputra, Geby; Suzuki, Mitsutoshi; Saito, Masaki

2017-01-01

Reactor criticality condition and fuel conversion capability are depending on the fuel arrangement schemes, reactor core geometry and fuel burnup process as well as the effect of different fuel cycle and fuel composition. Criticality condition of reactor core and breeding ratio capability have been investigated in this present study based on fast breeder reactor (FBR) type for different loaded fuel compositions of plutonium in the fuel core regions. Loaded fuel of Plutonium compositions are based on spent nuclear fuel (SNF) of light water reactor (LWR) for different fuel burnup process and cooling time conditions of the reactors. Obtained results show that different initial fuels of plutonium gives a significant chance in criticality conditions and fuel conversion capability. Loaded plutonium based on higher burnup process gives a reduction value of criticality condition or less excess reactivity. It also obtains more fuel breeding ratio capability or more breeding gain. Some loaded plutonium based on longer cooling time of LWR gives less excess reactivity and in the same time, it gives higher breeding ratio capability of the reactors. More composition of even mass plutonium isotopes gives more absorption neutron which affects to decresing criticality or less excess reactivity in the core. Similar condition that more absorption neutron by fertile material or even mass plutonium will produce more fissile material or odd mass plutonium isotopes to increase the breeding gain of the reactor.

Photochemical isotope separation

DOEpatents

Robinson, C. Paul; Jensen, Reed J.; Cotter, Theodore P.; Greiner, Norman R.; Boyer, Keith

1987-01-01

A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

Photochemical isotope separation

DOEpatents

Robinson, C.P.; Jensen, R.J.; Cotter, T.P.; Greiner, N.R.; Boyer, K.

1987-04-28

A process is described for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium. 8 figs.

CONVERSION OF PLUTONIUM TRIFLUORIDE TO PLUTONIUM TETRAFLUORIDE

DOEpatents

Fried, S.; Davidson, N.R.

1957-09-10

A large proportion of the trifluoride of plutonium can be converted, in the absence of hydrogen fluoride, to the tetrafiuoride of plutonium. This is done by heating plutonium trifluoride with oxygen at temperatures between 250 and 900 deg C. The trifiuoride of plutonium reacts with oxygen to form plutonium tetrafluoride and plutonium oxide, in a ratio of about 3 to 1. In the presence of moisture, plutonium tetrafluoride tends to hydrolyze at elevated temperatures and therefore it is desirable to have the process take place under anhydrous conditions.

A Graphical Examination of Uranium and Plutonium Fissility

ERIC Educational Resources Information Center

Reed, B. Cameron

2008-01-01

The issue of why only particular isotopes of uranium and plutonium are suitable for use in nuclear weapons is analyzed with the aid of graphs and semiquantitative discussions of parameters such as excitation energies, fission barriers, reaction cross-sections, and the role of processes such as [alpha]-decay and spontaneous fission. The goal is to…

The oceanic budgets of nickel and zinc isotopes: the importance of sulfidic environments as illustrated by the Black Sea

PubMed Central

Little, Susan H.; Archer, Corey; Cameron, Vyllinniskii; Andersen, Morten B.; Rijkenberg, Micha J. A.; Lyons, Timothy W.

2016-01-01

Isotopic data collected to date as part of the GEOTRACES and other programmes show that the oceanic dissolved pool is isotopically heavy relative to the inputs for zinc (Zn) and nickel (Ni). All Zn sinks measured until recently, and the only output yet measured for Ni, are isotopically heavier than the dissolved pool. This would require either a non-steady-state ocean or other unidentified sinks. Recently, isotopically light Zn has been measured in organic carbon-rich sediments from productive upwelling margins, providing a potential resolution of this issue, at least for Zn. However, the origin of the isotopically light sedimentary Zn signal is uncertain. Cellular uptake of isotopically light Zn followed by transfer to sediment does not appear to be a quantitatively important process. Here, we present Zn and Ni isotope data for the water column and sediments of the Black Sea. These data demonstrate that isotopically light Zn and Ni are extracted from the water column, probably through an equilibrium fractionation between different dissolved species followed by sequestration of light Zn and Ni in sulfide species to particulates and the sediment. We suggest that a similar, non-quantitative, process, operating in porewaters, explains the Zn data from organic carbon-rich sediments. This article is part of the themed issue ‘Biological and climatic impacts of ocean trace element chemistry’. PMID:29035259

Biogeochemical cycling of zinc and its isotopes in the Southern Ocean

NASA Astrophysics Data System (ADS)

Zhao, Y.; Vance, D.; Abouchami, W.; de Baar, H. J. W.

2014-01-01

the diatom frustule during growth. Experimental data are consistent with little or no fractionation during incorporation of Zn into this material. On the other hand, the light zinc at 40-80 m is most consistent with the regeneration of an intra-cellular pool that both culturing experiments and field data suggest will be isotopically light. The data thus imply two processes by which Zn is taken up in the surface ocean, that these pools have very different regeneration lengthscales, and that physical mixing of the oceans cannot eradicate their isotopic signatures. Finally, the deep δ66Zn ocean value is significantly higher than the current best estimate of the input to the oceans. The most obvious candidate for the required light sink is the survival of some of the cellular Zn to be buried in sediment.

Zinc and Its Isotopes in the Loire River Basin, France

NASA Astrophysics Data System (ADS)

Millot, R.; Desaulty, A. M.; Bourrain, X.

2014-12-01

The contribution of human activities such as industries, agriculture and domestic inputs, becomes more and more significant in the chemical composition of the dissolved load of rivers. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river basins include anthropogenic disturbances. The Loire River in central France is approximately 1010 km long and drains an area of 117,800 km2. In the upper basin, the bedrock is old plutonic rock overlain by much younger volcanic rocks. The intermediate basin includes three major tributaries flowing into the Loire River from the left bank: the Cher, the Indre and the Vienne rivers; the main stream flows westward and its valley stretches toward the Atlantic Ocean. Here, the Loire River drains the sedimentary series of the Paris Basin, mainly carbonate deposits. The lower Loire basin drains pre-Mesozoic basement of the Armorican Massif and its overlying Mesozoic to Cenozoic sedimentary deposits. The Loire River is one of the main European riverine inputs to the Atlantic ocean. Here we are reporting concentration and isotope data for Zn in river waters and suspended sediments from the Loire River Basin. In addition, we also report concentration and isotope data for the different industrial sources within the Loire Basin, as well as data for biota samples such as mussels and oysters from the Bay of Biscay and North Brittany. These organisms are known to be natural accumulators of metal pollutants. Zinc isotopic compositions are rather homogeneous in river waters with δ66Zn values ranging from 0.21 to 0.39‰. This range of variation is very different from anthropogenic signature (industrial and/or agriculture release) that displays δ66Zn values between 0.02 to 0.14‰. This result is in agreement with a geogenic origin and the low Zn concentrations in the Loire River Basin (from 0.8 to 6 µg/L).

Forensic investigation of plutonium metal: a case study of CRM 126

DOE PAGES

Byerly, Benjamin L.; Stanley, Floyd; Spencer, Khal; ...

2016-11-01

In our study, a certified plutonium metal reference material (CRM 126) with a known production history is examined using analytical methods that are commonly employed in nuclear forensics for provenancing and attribution. Moreover, the measured plutonium isotopic composition and actinide assay are consistent with values reported on the reference material certificate. Model ages from U/Pu and Am/Pu chronometers agree with the documented production timeline. Finally, these results confirm the utility of these analytical methods and highlight the importance of a holistic approach for forensic study of unknown materials.

PLUTONIUM-CERIUM-COBALT AND PLUTONIUM-CERIUM-NICKEL ALLOYS

DOEpatents

Coffinberry, A.S.

1959-08-25

>New plutonium-base teroary alloys useful as liquid reactor fuels are described. The alloys consist of 10 to 20 atomic percent cobalt with the remainder plutonium and cerium in any desired proportion, with the plutonium not in excess of 88 atomic percent; or, of from 10 to 25 atomic percent nickel (or mixture of nickel and cobalt) with the remainder plutonium and cerium in any desired proportion, with the plutonium not in excess of 86 atomic percent. The stated advantages of these alloys over unalloyed plutonium for reactor fuel use are a lower melting point and a wide range of permissible plutonium dilution.

Zinc isotope evidence for sulfate-rich fluid transfer across subduction zones.

PubMed

Pons, Marie-Laure; Debret, Baptiste; Bouilhol, Pierre; Delacour, Adélie; Williams, Helen

2016-12-16

Subduction zones modulate the chemical evolution of the Earth's mantle. Water and volatile elements in the slab are released as fluids into the mantle wedge and this process is widely considered to result in the oxidation of the sub-arc mantle. However, the chemical composition and speciation of these fluids, which is critical for the mobility of economically important elements, remain poorly constrained. Sulfur has the potential to act both as oxidizing agent and transport medium. Here we use zinc stable isotopes (δ 66 Zn) in subducted Alpine serpentinites to decipher the chemical properties of slab-derived fluids. We show that the progressive decrease in δ 66 Zn with metamorphic grade is correlated with a decrease in sulfur content. As existing theoretical work predicts that Zn-SO 4 2- complexes preferentially incorporate heavy δ 66 Zn, our results provide strong evidence for the release of oxidized, sulfate-rich, slab serpentinite-derived fluids to the mantle wedge.

Zinc isotope evidence for sulfate-rich fluid transfer across subduction zones

PubMed Central

Pons, Marie-Laure; Debret, Baptiste; Bouilhol, Pierre; Delacour, Adélie; Williams, Helen

2016-01-01

Subduction zones modulate the chemical evolution of the Earth's mantle. Water and volatile elements in the slab are released as fluids into the mantle wedge and this process is widely considered to result in the oxidation of the sub-arc mantle. However, the chemical composition and speciation of these fluids, which is critical for the mobility of economically important elements, remain poorly constrained. Sulfur has the potential to act both as oxidizing agent and transport medium. Here we use zinc stable isotopes (δ66Zn) in subducted Alpine serpentinites to decipher the chemical properties of slab-derived fluids. We show that the progressive decrease in δ66Zn with metamorphic grade is correlated with a decrease in sulfur content. As existing theoretical work predicts that Zn-SO42− complexes preferentially incorporate heavy δ66Zn, our results provide strong evidence for the release of oxidized, sulfate-rich, slab serpentinite-derived fluids to the mantle wedge. PMID:27982033

Chemical Disposition of Plutonium in Hanford Site Tank Wastes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delegard, Calvin H.; Jones, Susan A.

2015-05-07

This report examines the chemical disposition of plutonium (Pu) in Hanford Site tank wastes, by itself and in its observed and potential interactions with the neutron absorbers aluminum (Al), cadmium (Cd), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), and sodium (Na). Consideration also is given to the interactions of plutonium with uranium (U). No consideration of the disposition of uranium itself as an element with fissile isotopes is considered except tangentially with respect to its interaction as an absorber for plutonium. The report begins with a brief review of Hanford Site plutonium processes, examining the various means used tomore » recover plutonium from irradiated fuel and from scrap, and also examines the intermediate processing of plutonium to prepare useful chemical forms. The paper provides an overview of Hanford tank defined-waste–type compositions and some calculations of the ratios of plutonium to absorber elements in these waste types and in individual waste analyses. These assessments are based on Hanford tank waste inventory data derived from separately published, expert assessments of tank disposal records, process flowsheets, and chemical/radiochemical analyses. This work also investigates the distribution and expected speciation of plutonium in tank waste solution and solid phases. For the solid phases, both pure plutonium compounds and plutonium interactions with absorber elements are considered. These assessments of plutonium chemistry are based largely on analyses of idealized or simulated tank waste or strongly alkaline systems. The very limited information available on plutonium behavior, disposition, and speciation in genuine tank waste also is discussed. The assessments show that plutonium coprecipitates strongly with chromium, iron, manganese and uranium absorbers. Plutonium’s chemical interactions with aluminum, nickel, and sodium are minimal to non-existent. Credit for neutronic interaction of plutonium with these

Method of isotope separation by chemi-ionization

DOEpatents

Wexler, Sol; Young, Charles E.

1977-05-17

A method for separating specific isotopes present in an isotopic mixture by aerodynamically accelerating a gaseous compound to form a jet of molecules, and passing the jet through a stream of electron donor atoms whereby an electron transfer takes place, thus forming negative ions of the molecules. The molecular ions are then passed through a radiofrequency quadrupole mass filter to separate the specific isotopes. This method may be used for any compounds having a sufficiently high electron affinity to permit negative ion formation, and is especially useful for the separation of plutonium and uranium isotopes.

Dissolution of aerosol particles collected from nuclear facility plutonium production process

DOE PAGES

Xu, Ning; Martinez, Alexander; Schappert, Michael Francis; ...

2015-08-14

Here, a simple, robust analytical chemistry method has been developed to dissolve plutonium containing particles in a complex matrix. The aerosol particles collected on Marple cascade impactor substrates were shown to be dissolved completely with an acid mixture of 12 M HNO 3 and 0.1 M HF. A pressurized closed vessel acid digestion technique was utilized to heat the samples at 130 °C for 16 h to facilitate the digestion. The dissolution efficiency for plutonium particles was 99 %. The resulting particle digestate solution was suitable for trace elemental analysis and isotope composition determination, as well as radiochemistry measurements.

Assessment of the global fallout of plutonium isotopes and americium-241 in the soil of the central region of Saudi Arabia.

PubMed

Shabana, E I; Al-Shammari, H L

2001-01-01

A radiochemical technique for determination of plutonium isotopes and 241Am in soil samples is tested against IAEA-standard reference materials to determine its accuracy and precision for reliable results. The technique is then used in the investigation of topsoil samples, collected from the natural environment of the central region of Saudi Arabia, to assess the effect of fallout accumulation of these radionuclides in the region. Plutonium and americium were sequentially separated from all other components of the sample by anion-exchange chromatography and co-precipitated with Nd3+ as fluorides. The precipitates were mounted on membrane filters and measured using a high-resolution alpha-spectrometer. The results of the analysis of the reference materials showed satisfactory sensitivity and precision of the technique. The results of the analyzed soil samples show activity levels ranging from < LLD to 0.089 and from

Experiments and Monte Carlo modeling of a higher resolution Cadmium Zinc Telluride detector for safeguards applications

NASA Astrophysics Data System (ADS)

Borella, Alessandro

2016-09-01

The Belgian Nuclear Research Centre is engaged in R&D activity in the field of Non Destructive Analysis on nuclear materials, with focus on spent fuel characterization. A 500 mm3 Cadmium Zinc Telluride (CZT) with enhanced resolution was recently purchased. With a full width at half maximum of 1.3% at 662 keV, the detector is very promising in view of its use for applications such as determination of uranium enrichment and plutonium isotopic composition, as well as measurement on spent fuel. In this paper, I report about the work done with such a detector in terms of its characterization. The detector energy calibration, peak shape and efficiency were determined from experimental data. The data included measurements with calibrated sources, both in a bare and in a shielded environment. In addition, Monte Carlo calculations with the MCNPX code were carried out and benchmarked with experiments.

Isotope separation by laser means

DOEpatents

Robinson, C. Paul; Jensen, Reed J.; Cotter, Theodore P.; Greiner, Norman R.; Boyer, Keith

1982-06-15

A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

Zinc isotopic fractionation in Phragmites australis in response to toxic levels of zinc

PubMed Central

Caldelas, Cristina; Dong, Shuofei; Araus, José Luis; Jakob Weiss, Dominik

2011-01-01

Stable isotope signatures of Zn have shown great promise in elucidating changes in uptake and translocation mechanisms of this metal in plants during environmental changes. Here this potential was tested by investigating the effect of high Zn concentrations on the isotopic fractionation patterns of Phragmites australis (Cav.) Trin. ex Steud. Plants were grown for 40 d in a nutritive solution containing 3.2 μM (sufficient) or 2 mM (toxic) Zn. The Zn isotopic composition of roots, rhizomes, shoots, and leaves was analysed. Stems and leaves were sampled at different heights to evaluate the effect of long-distance transport on Zn fractionation. During Zn sufficiency, roots, rhizomes, and shoots were isotopically heavy (δ66ZnJMC Lyon=0.2‰) while the youngest leaves were isotopically light (–0.5‰). During Zn excess, roots were still isotopically heavier (δ66Zn=0.5‰) and the rest of the plant was isotopically light (up to –0.5‰). The enrichment of heavy isotopes at the roots was attributed to Zn uptake mediated by transporter proteins under Zn-sufficient conditions and to chelation and compartmentation in Zn excess. The isotopically lighter Zn in shoots and leaves is consistent with long-distance root to shoot transport. The tolerance response of P. australis increased the range of Zn fractionation within the plant and with respect to the environment. PMID:21193582

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

DOEpatents

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

1962-11-13

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

Verification of Plutonium Content in PuBe Sources Using MCNP® 6.2.0 Beta with TENDL 2012 Libraries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lockhart, Madeline Louise; McMath, Garrett Earl

Although the production of PuBe neutron sources has discontinued, hundreds of sources with unknown or inaccurately declared plutonium content are in existence around the world. Institutions have undertaken the task of assaying these sources, measuring, and calculating the isotopic composition, plutonium content, and neutron yield. The nominal plutonium content, based off the neutron yield per gram of pure 239Pu, has shown to be highly inaccurate. New methods of measuring the plutonium content allow a more accurate estimate of the true Pu content, but these measurements need verification. Using the TENDL 2012 nuclear data libraries, MCNP6 has the capability to simulatemore » the (α, n) interactions in a PuBe source. Theoretically, if the source is modeled according to the plutonium content, isotopic composition, and other source characteristics, the calculated neutron yield in MCNP can be compared to the experimental yield, offering an indication of the accuracy of the declared plutonium content. In this study, three sets of PuBe sources from various backgrounds were modeled in MCNP6 1.2 Beta, according to the source specifications dictated by the individuals who assayed the source. Verification of the source parameters with MCNP6 also serves as a means to test the alpha transport capabilities of MCNP6 1.2 Beta with TENDL 2012 alpha transport libraries. Finally, good agreement in the comparison would indicate the accuracy of the source parameters in addition to demonstrating MCNP's capabilities in simulating (α, n) interactions.« less

Verification of Plutonium Content in PuBe Sources Using MCNP® 6.2.0 Beta with TENDL 2012 Libraries

DOE PAGES

Lockhart, Madeline Louise; McMath, Garrett Earl

2017-10-26

Although the production of PuBe neutron sources has discontinued, hundreds of sources with unknown or inaccurately declared plutonium content are in existence around the world. Institutions have undertaken the task of assaying these sources, measuring, and calculating the isotopic composition, plutonium content, and neutron yield. The nominal plutonium content, based off the neutron yield per gram of pure 239Pu, has shown to be highly inaccurate. New methods of measuring the plutonium content allow a more accurate estimate of the true Pu content, but these measurements need verification. Using the TENDL 2012 nuclear data libraries, MCNP6 has the capability to simulatemore » the (α, n) interactions in a PuBe source. Theoretically, if the source is modeled according to the plutonium content, isotopic composition, and other source characteristics, the calculated neutron yield in MCNP can be compared to the experimental yield, offering an indication of the accuracy of the declared plutonium content. In this study, three sets of PuBe sources from various backgrounds were modeled in MCNP6 1.2 Beta, according to the source specifications dictated by the individuals who assayed the source. Verification of the source parameters with MCNP6 also serves as a means to test the alpha transport capabilities of MCNP6 1.2 Beta with TENDL 2012 alpha transport libraries. Finally, good agreement in the comparison would indicate the accuracy of the source parameters in addition to demonstrating MCNP's capabilities in simulating (α, n) interactions.« less

Digital pile-up rejection for plutonium experiments with solution-grown stilbene

NASA Astrophysics Data System (ADS)

Bourne, M. M.; Clarke, S. D.; Paff, M.; DiFulvio, A.; Norsworthy, M.; Pozzi, S. A.

2017-01-01

A solution-grown stilbene detector was used in several experiments with plutonium samples including plutonium oxide, mixed oxide, and plutonium metal samples. Neutrons from different reactions and plutonium isotopes are accompanied by numerous gamma rays especially by the 59-keV gamma ray of 241Am. Identifying neutrons correctly is important for nuclear nonproliferation applications and makes neutron/gamma discrimination and pile-up rejection necessary. Each experimental dataset is presented with and without pile-up filtering using a previously developed algorithm. The experiments were simulated using MCNPX-PoliMi, a Monte Carlo code designed to accurately model scintillation detector response. Collision output from MCNPX-PoliMi was processed using the specialized MPPost post-processing code to convert neutron energy depositions event-by-event into light pulses. The model was compared to experimental data after pulse-shape discrimination identified waveforms as gamma ray or neutron interactions. We show that the use of the digital pile-up rejection algorithm allows for accurate neutron counting with stilbene to within 2% even when not using lead shielding.

Zinc isotope and transition-element dynamics accompanying hydrozincite biomineralization in the Rio Naracauli, Sardinia, Italy

USGS Publications Warehouse

Wanty, Richard B.; Podda, F.; De Giudici, Giovanni; Cidu, R.; Lattanzi, Pierfranco

2013-01-01

The Rio Naracauli in SW Sardinia drains part of the Ingurtosu Zn–Pb mining district, and contains extreme concentrations of dissolved Zn at near-neutral pH. In the upper reaches of the stream, pH, alkalinity and Zn concentrations are such that hydrozincite [Zn5(CO3)2(OH)6] precipitates in a biologically mediated process facilitated by a microalga (Chlorella sp.) and a cyanobacterium (Scytonema sp.). Values of δ66Zn in water and solid samples ranged from − 0.35‰ to + 0.5‰ relative to the JMC 3-0749-Lyon standard, and closely follow a mass-dependent fractionation line. Two composite samples of sphalerite, the primary ore mineral in the Ingurtosu deposits, had an average δ66Zn of + 0.15‰, similar to sphalerite measured elsewhere in hydrothermal mineral deposits. Zinc isotope measurements of the stream water and the hydrozincite forming in the stream show a consistent preference for the heavy isotope, 66Zn, in the hydrozincite relative to 64Zn. Synthetic hydrozincites produced without added bacteria have δ66Zn identical to the dissolved Zn, thus suggesting a biologically mediated mineralization process in Rio Naracauli. The average fractionation, Δhdz-water, is 0.35‰, the magnitude of which is consistent with other studies, and suggests an extracellular mechanism of the biomineralization process. Zinc concentration and dissolved δ66Zn steadily decrease in the reach of the stream where the biomineralization occurs. The biomineralization process also leads to the sequestration of Pb, Cu and Ni in the hydrozincite lattice, and the coeval precipitation of an amorphous CdCO3 solid, prompting the suggestion that if optimized, the biomineralization process might represent a feasible passive remediation strategy for streams with high Zn and other metals, and with near-neutral pH.

The Marine Biogeochemistry of Zinc Isotopes

DTIC Science & Technology

2007-06-01

hydrothermal fluids and minerals, cultured marine phytoplankton, natural plankton, and seawater. By measuring Zn isotopes in a diverse array of...variations were discovered in hydrothermal fluids and minerals, with hydrothermal fluids ranging in 6 66Zn from 0.02 %o to +0.93 %o, and chimney minerals...drives much of the Zn isotope fractionation in hydrothermal systems. In cultured diatoms, a relationship was discovered between Zn transport by

Some neutron and gamma radiation characteristics of plutonium cermet fuel for isotopic power sources

NASA Technical Reports Server (NTRS)

Neff, R. A.; Anderson, M. E.; Campbell, A. R.; Haas, F. X.

1972-01-01

Gamma and neutron measurements on various types of plutonium sources are presented in order to show the effects of O-17, O-18 F-19, Pu-236, age of the fuel, and size of the source on the gamma and neutron spectra. Analysis of the radiation measurements shows that fluorine is the main contributor to the neutron yields from present plutonium-molybdenum cermet fuel, while both fluorine and Pu-236 daughters contribute significantly to the gamma ray intensities.

Preparation of organic and water hydrogen for stable isotope analysis. Effects due to reaction vessels and zinc reagent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schimmelmann, A.; DeNiro, M.J.

1993-03-15

Combustion of organic matter in sealed Pyrex, Vycor, and quartz ampules at temperatures between 520 and 900[degrees]C yields less than stoichiometric amounts of water. The loss of hydrogen to hydration reactions between water vapor and glass/quartz interferes with the determination of C/H and N/H elemental ratios in organic matter. The effect increases from quartz to Vycor to Pyrex, but the incomplete yield does not significantly affect the precision and accuracy of the determination of stable hydrogen isotope ratios. Reactions between water and Pyrex do not affect the conversion of water to hydrogen with zinc in Pyrex ampules at 500[degrees]C, whichmore » is quantitative, but even preoutgassed zinc contains a deuterium-depleted hydrogen blank. D/H ratios in hydrogen from the Zn method require a nonlinear correction to achieve compatibility with [delta]D values from the uranium method. 19 refs., 4 tabs.« less

Iron Bioavailability from Ferric Pyrophosphate in Extruded Rice Cofortified with Zinc Sulfate Is Greater than When Cofortified with Zinc Oxide in a Human Stable Isotope Study.

PubMed

Hackl, Laura; Zimmermann, Michael B; Zeder, Christophe; Parker, Megan; Johns, Paul W; Hurrell, Richard F; Moretti, Diego

2017-03-01

Background: Extruded rice grains are often cofortified with iron and zinc. However, it is uncertain if the addition of zinc to iron-fortified rice affects iron absorption and whether this is zinc-compound specific. Objective: We investigated whether zinc, added as zinc oxide (ZnO) or zinc sulfate (ZnSO 4 ), affects human iron absorption from extruded rice fortified with ferric pyrophosphate (FePP). Methods: In 19 iron-depleted Swiss women (plasma ferritin ≤16.5 μ/L) aged between 20 and 39 y with a normal body mass index (in kg/m 2 ; 18.7-24.8), we compared iron absorption from 4 meals containing fortified extruded rice with 4 mg Fe and 3 mg Zn. Three of the meals contained extruded rice labeled with FePP ( 57 FePP): 1 ) 1 meal without added zinc ( 57 FePP-Zn), 2 ) 1 cofortified with ZnO ( 57 FePP+ZnO), and 3 ) 1 cofortified with ZnSO 4 ( 57 FePP+ZnSO 4 ). The fourth meal contained extruded rice without iron or zinc, extrinsically labeled with ferrous sulfate ( 58 FeSO 4 ) added as a solution after cooking. All 4 meals contained citric acid. Iron bioavailability was measured by isotopic iron ratios in red blood cells. We also measured relative in vitro iron solubility from 57 FePP-Zn, 57 FePP+ZnO, and 57 FePP+ZnSO 4 expressed as a fraction of FeSO 4 solubility. Results: Geometric mean fractional iron absorption (95% CI) from 57 FePP+ZnSO 4 was 4.5% (3.4%, 5.8%) and differed from 57 FePP+ZnO (2.7%; 1.8%, 4.1%) ( P < 0.03); both did not differ from 57 FePP-Zn: 4.0% (2.8%, 5.6%). Relative iron bioavailabilities compared with 58 FeSO 4 were 62%, 57%, and 38% from 57 FePP+ZnSO 4 , 57 FePP-Zn, and 57 FePP+ZnO, respectively. In vitro solubility from 57 FePP+ZnSO 4 differed from that of 57 FePP-Zn (14.3%; P < 0.02) but not from that of 57 FePP+ZnO (10.2% compared with 13.1%; P = 0.08). Conclusions: In iron-depleted women, iron absorption from FePP-fortified extruded rice cofortified with ZnSO 4 was 1.6-fold (95% CI: 1.4-, 1.9-fold) that of rice cofortified with Zn

Comparison of complementary feeding strategies to meet zinc requirements of older breastfed infants1234

PubMed Central

Krebs, Nancy F; Westcott, Jamie E; Culbertson, Diana L; Sian, Lei; Miller, Leland V; Hambidge, K Michael

2012-01-01

Background: The low zinc intake from human milk at ∼6 mo of age predicts the dependence on complementary foods (CF) to meet the zinc requirements of older breastfed-only infants. Objective: The objective of this study was to compare major variables of zinc homeostasis and zinc status in 9-mo-old breastfed infants who were randomly assigned to different complementary food regimens. Design: Forty-five exclusively breastfed 5-mo-old infants were randomly assigned to receive commercially available pureed meats, iron-and-zinc–fortified infant cereal (IZFC), or whole-grain, iron-only–fortified infant cereal (IFC) as the first and primary CF until completion of zinc metabolic studies between 9 and 10 mo of age. A zinc stable-isotope methodology was used to measure the fractional absorption of zinc (FAZ) in human milk and CF by dual-isotope ratios in urine. Calculated variables included the dietary intake from duplicate diets and 4-d test weighing, the total absorbed zinc (TAZ) from FAZ × diet zinc, and the exchangeable zinc pool size (EZP) from isotope enrichment in urine. Results: Mean daily zinc intakes were significantly greater for the meat and IZFC groups than for the IFC group (P < 0.001); only intakes in meat and IZFC groups met estimated average requirements. Mean (±SEM) TAZ amounts were 0.80 ± 0.08, 0.71 ± 0.09, and 0.52 ± 0.05 mg/d for the meat, IZFC, and IFC groups, respectively (P = 0.027). Zinc from human milk contributed <25% of TAZ for all groups. The EZP correlated with both zinc intake (r = 0.43, P < 0.01) and TAZ (r = 0.54, P < 0.001). Conclusion: Zinc requirements for older breastfed-only infants are unlikely to be met without the regular consumption of either meats or zinc-fortified foods. PMID:22648720

Effect of dietary phytate on zinc homeostasis in young and elderly Korean women.

PubMed

Kim, Jihye; Paik, Hee Young; Joung, Hyojee; Woodhouse, Leslie R; Li, Shanji; King, Janet C

2007-02-01

Previous studies suggest that consumption of predominantly plant-based diets with high phytate content contribute to zinc deficiency by inhibiting zinc absorption. Age of the individual may also affect the ability to maintain zinc homeostasis. This study was designed to determine the effect of dietary phytate on zinc homeostasis and to evaluate the effect of age on the capacity to maintain the zinc homeostasis with changes in dietary phytate in young and elderly Korean women. Seven healthy young women (22-24 yr) and 10 healthy elderly women (66-75 yr) were studied consecutively for 3 months in 2 metabolic periods (MP) in two different metabolic units. During MP1 the women consumed a high phytate (HP) diet (P:Zn molar ratio = 23) for 9 days. After a 10 d wash-out period at home eating their usual diets, a lower phytate diet (LP) (P:Zn molar ratio = 10) was fed in MP2 for 9 d. Phytase was added to selected foods in the high phytate diet to reduce the phytate content of the meals in the LP period. The zinc content of both diets was about 6.5 mg/d. Stable isotopes of Zn ((70)Zn) were administered intravenously on d 5 of MP 1 and 2 for measuring endogenous fecal zinc excretion. Plasma samples were also collected on d 5 for measuring plasma zinc concentrations by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). 24 hr urine samples were collected for 5 d and complete fecal samples were collected for 9 d after isotope administration. Fractional zinc absorption (FZA) was calculated from mass balance corrected for endogenous fecal zinc (EFZ) excretion and EFZ was determined by using an isotopic dilution technique. Isotopic ratios for FZA and EFZ were measured by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Statistical analyses were done using ANOVA. Both the young and elderly women were in negative zinc balance during the HP period. This was due to a significant decrease in FZA and total absorbed zinc (TAZ) with a HP diet (43 vs 22% in young women

Calibrating NIST SRM 683 as A New International Reference Standard for Zn Isotopes

NASA Astrophysics Data System (ADS)

Yang, Y.; Zhang, X.; Yu, H.; Huang, F.

2017-12-01

Zinc isotopes have been widely applied in the cosmochemical, geochemical, and environmental studies (Moynier et al. 2017). Obtaining precise Zn isotopic data for inter-laboratory comparison is a prerequisite to these applications. Currently, the JMC3-0749L is the primary reference standard for Zn isotopes (Albarède 2004), but it is not commercially available now. Thus, it is necessary to calibrate a new international primary reference standard for Zn isotopic analysis. Chen et al. (2016) showed that NIST SRM 683 (a pure Zn metal nugget of 140 grams) has a δ66ZnJMC of 0.12‰, which is falling within the range of natural Zn isotopic compositions, and it may a good candidate for the next generation of international reference standard (Chen et al. 2016). In order to further examine whether NIST SRM 683 has a homogeneous Zn isotopic composition, we measured more NIST SRM 683 by double-spike methods using MC-ICPMS (Conway et al. 2013). The metal nuggets of NIST SRM 683 were intensively sampled by micro-drilling. Zinc isotope analyses for two nuggets show that they have δ66Zn of 0.14 ± 0.02‰ (2SD, N = 32) and 0.13 ± 0.02‰ (2SD, N = 33), respectively. These values are similar to those of two Zn metal nuggets (0.11 ± 0.02‰ vs. 0.12 ± 0.02‰) reported previously by Chen et al. (2016). We fully dissolved one nugget, producing pure Zn solution with identical Zn isotopic composition with the drilling samples. All results strongly support that NIST SRM 683 is homogeneous in Zn isotopic compositions which could be an ideal candidate for the next reference for Zn isotopes. Tests on more metal nuggets will be performed in a few months for further confirming the Zn isotope compositions and homogeneity. Reference: Albarède et al., 2004. 'The stable isotope geochemistry of copper and zinc', Reviews in Mineralogy and Geochemistry, 55: 409-27. Chen et al., 2016. 'Zinc Isotopic Compositions of NIST SRM 683 and Whole-Rock Reference Materials', Geostandards and

Zinc and volatile element loss during planetary magma ocean phases

NASA Astrophysics Data System (ADS)

Dhaliwal, Jasmeet K.; Day, James M. D.; Moynier, Frédéric

2016-10-01

Zinc is a moderately volatile element and a key tracer of volatile depletion on planetary bodies due to lack of significant isotopic fractionation under high-temperature processes. Terrestrial basalts have δ66Zn values similar to some chondrites (+ 0.15 to 0.3‰ where [{66Zn/64Znsample/66Zn/64ZnJMC-Lyon-1} × 1000]) and elevated Zn concentrations (100 ppm). Lunar mare basalts yield a mean δ66Zn value of +1.4 ± 0.5‰ and have low Zn concentrations (~2 ppm). Late-stage lunar magmatic products, such as ferroan anorthosite, Mg-suite and Alkali suite rocks exhibit heavier δ66Zn values (+3 to +6‰). The heavy δ66Zn lunar signature is thought to reflect evaporative loss and fractionation of zinc, either during a giant impact or in a magma ocean phase.We explore conditions of volatile element loss within a lunar magma ocean (LMO) using models of Zn isotopic fractionation that are widely applicable to planetary magma oceans. For the Moon, our objective was to identify conditions that would yield a δ66Zn signature of ~ +1.4‰ within the mantle, assuming a terrestrial mantle zinc starting composition.We examine two cases of zinc evaporative fractionation: (1) lunar surface zinc fractionation that was completed prior to LMO crystallization and (2) lunar surface zinc fractionation that was concurrent with LMO crystallization. The first case resulted in a homogeneous lunar mantle and the second case yielded a stratified lunar mantle, with the greatest zinc isotopic enrichment in late-stage crystallization products. This latter case reproduces the distribution of zinc isotope compositions in lunar materials quite well.We find that hydrodynamic escape was not a dominant process in losing Zn, but that erosion of a nascent lunar atmosphere, or separation of condensates into a proto-lunar crust are possible. While lunar volatile depletion is still possible as a consequence of the giant impact, this process cannot reproduce the variable δ66Zn found in the Moon. Outgassing

SEPARATION OF PLUTONIUM

DOEpatents

Maddock, A.G.; Smith, F.

1959-08-25

A method is described for separating plutonium from uranium and fission products by treating a nitrate solution of fission products, uranium, and hexavalent plutonium with a relatively water-insoluble fluoride to adsorb fission products on the fluoride, treating the residual solution with a reducing agent for plutonium to reduce its valence to four and less, treating the reduced plutonium solution with a relatively insoluble fluoride to adsorb the plutonium on the fluoride, removing the solution, and subsequently treating the fluoride with its adsorbed plutonium with a concentrated aqueous solution of at least one of a group consisting of aluminum nitrate, ferric nitrate, and manganous nitrate to remove the plutonium from the fluoride.

The behavior of iron and zinc stable isotopes accompanying the subduction of mafic oceanic crust: A case study from Western Alpine ophiolites

NASA Astrophysics Data System (ADS)

Inglis, Edward C.; Debret, Baptiste; Burton, Kevin W.; Millet, Marc-Alban; Pons, Marie-Laure; Dale, Christopher W.; Bouilhol, Pierre; Cooper, Matthew; Nowell, Geoff M.; McCoy-West, Alex J.; Williams, Helen M.

2017-07-01

Arc lavas display elevated Fe3+/ΣFe ratios relative to MORB. One mechanism to explain this is the mobilization and transfer of oxidized or oxidizing components from the subducting slab to the mantle wedge. Here we use iron and zinc isotopes, which are fractionated upon complexation by sulfide, chloride, and carbonate ligands, to remark on the chemistry and oxidation state of fluids released during prograde metamorphism of subducted oceanic crust. We present data for metagabbros and metabasalts from the Chenaillet massif, Queyras complex, and the Zermatt-Saas ophiolite (Western European Alps), which have been metamorphosed at typical subduction zone P-T conditions and preserve their prograde metamorphic history. There is no systematic, detectable fractionation of either Fe or Zn isotopes across metamorphic facies, rather the isotope composition of the eclogites overlaps with published data for MORB. The lack of resolvable Fe isotope fractionation with increasing prograde metamorphism likely reflects the mass balance of the system, and in this scenario Fe mobility is not traceable with Fe isotopes. Given that Zn isotopes are fractionated by S-bearing and C-bearing fluids, this suggests that relatively small amounts of Zn are mobilized from the mafic lithologies in within these types of dehydration fluids. Conversely, metagabbros from the Queyras that are in proximity to metasediments display a significant Fe isotope fractionation. The covariation of δ56Fe of these samples with selected fluid mobile elements suggests the infiltration of sediment derived fluids with an isotopically light signature during subduction.

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

Molybdenum and zinc stable isotope variation in mining waste rock drainage and waste rock at the Antamina mine, Peru.

PubMed

Skierszkan, E K; Mayer, K U; Weis, D; Beckie, R D

2016-04-15

The stable isotope composition of molybdenum (Mo) and zinc (Zn) in mine wastes at the Antamina Copper-Zn-Mo mine, Peru, was characterized to investigate whether isotopic variation of these elements indicated metal attenuation processes in mine drainage. Waste rock and ore minerals were analyzed to identify the isotopic composition of Mo and Zn sources, namely molybdenites (MoS2) and sphalerites (ZnS). Molybdenum and Zn stable isotope ratios are reported relative to the NIST-SRM-3134 and PCIGR-1 Zn standards, respectively. δ(98)Mo among molybdenites ranged from -0.6 to +0.6‰ (n=9) while sphalerites showed no δ(66)Zn variations (0.11±0.01‰, 2 SD, n=5). Mine drainage samples from field waste rock weathering experiments were also analyzed to examine the extent of isotopic variability in the dissolved phase. Variations spanned 2.2‰ in δ(98)Mo (-0.1 to +2.1‰) and 0.7‰ in δ(66)Zn (-0.4 to +0.3‰) in mine drainage over a wide pH range (pH2.2-8.6). Lighter δ(66)Zn signatures were observed in alkaline pH conditions, which was consistent with Zn adsorption and/or hydrozincite (Zn5(OH)6(CO3)2) formation. However, in acidic mine drainage Zn isotopic compositions reflected the value of sphalerites. In addition, molybdenum isotope compositions in mine drainage were shifted towards heavier values (0.89±1.25‰, 2 SD, n=16), with some overlap, in comparison to molybdenites and waste rock (0.13±0.82‰, 2 SD, n=9). The cause of heavy Mo isotopic signatures in mine drainage was more difficult to resolve due to isotopic heterogeneity among ore minerals and a variety of possible overlapping processes including dissolution, adsorption and secondary mineral precipitation. This study shows that variation in metal isotope ratios are promising indicators of metal attenuation. Future characterization of isotopic fractionation associated to key environmental reactions will improve the power of Mo and Zn isotope ratios to track the fate of these elements in mine drainage

Zinc isotope anomalies. [in Allende meteorite

NASA Technical Reports Server (NTRS)

Volkening, J.; Papanastassiou, D. A.

1990-01-01

The Zn isotope composition in refractory-element-rich inclusions of the Allende meteorite are determined. Typical inclusions contain normal Zn. A unique inclusion of the Allende meteorite shows an excess for Zn-66 of 16.7 + or - 3.7 eu (1 eu = 0.01 percent) and a deficit for Zn-70 of 21 + or - 13 eu. These results indicate the preservation of exotic components even for volatile elements in this inclusion. The observed excess Zn-66 correlates with excesses for the neutron-rich isotopes of Ca-48, Ti-50, Cr-54, and Fe-58 in the same inclusion.

Plutonium Bioassay Testing of U.S. Atmospheric Nuclear Test Participants and U.S. Occupation Forces of Hiroshima and Nagasaki, Japan

DTIC Science & Technology

2015-10-30

with nuclear weapons testing or plutonium work. The results for the 100 atomic veterans were compared to those of the unexposed population, and...as a marker for significant internal intakes of other associated radionuclides in nuclear weapons debris due to its low natural background. However...isotope in weapons grade plutonium, is important from a health perspective, its presence within a given urine sample being analyzed by FTA can only

Destructive analysis capabilities for plutonium and uranium characterization at Los Alamos National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tandon, Lav; Kuhn, Kevin J; Drake, Lawrence R

Los Alamos National Laboratory's (LANL) Actinide Analytical Chemistry (AAC) group has been in existence since the Manhattan Project. It maintains a complete set of analytical capabilities for performing complete characterization (elemental assay, isotopic, metallic and non metallic trace impurities) of uranium and plutonium samples in different forms. For a majority of the customers there are strong quality assurance (QA) and quality control (QC) objectives including highest accuracy and precision with well defined uncertainties associated with the analytical results. Los Alamos participates in various international and national programs such as the Plutonium Metal Exchange Program, New Brunswick Laboratory's (NBL' s) Safeguardsmore » Measurement Evaluation Program (SME) and several other inter-laboratory round robin exercises to monitor and evaluate the data quality generated by AAC. These programs also provide independent verification of analytical measurement capabilities, and allow any technical problems with analytical measurements to be identified and corrected. This presentation will focus on key analytical capabilities for destructive analysis in AAC and also comparative data between LANL and peer groups for Pu assay and isotopic analysis.« less

An overview of zinc addition for BWR dose rate control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marble, W.J.

1995-03-01

This paper presents an overview of the BWRs employing feedwater zinc addition to reduce primary system dose rates. It identifies which BWRs are using zinc addition and reviews the mechanical injection and passive addition hardware currently being employed. The impact that zinc has on plant chemistry, including the factor of two to four reduction in reactor water Co-60 concentrations, is discussed. Dose rate results, showing the benefits of implementing zinc on either fresh piping surfaces or on pipes with existing films are reviewed. The advantages of using zinc that is isotopically enhanced by the depletion of the Zn-64 precursor tomore » Zn-65 are identified.« less

Plutonium isotopes and 241Am in the atmosphere of Lithuania: A comparison of different source terms

NASA Astrophysics Data System (ADS)

Lujanienė, G.; Valiulis, D.; Byčenkienė, S.; Šakalys, J.; Povinec, P. P.

2012-12-01

137Cs, 241Am and Pu isotopes collected in aerosol samples during 1994-2011 were analyzed with special emphasis on better understanding of Pu and Am behavior in the atmosphere. The results from long-term measurements of 240Pu/239Pu atom ratios showed a bimodal frequency distribution with median values of 0.195 and 0.253, indicating two main sources contributing to the Pu activities at the Vilnius sampling station. The low Pu atom ratio of 0.141 could be attributed to the weapon-grade plutonium derived from the nuclear weapon test sites. The frequency of air masses arriving from the North-West and North-East correlated with the Pu atom ratio indicating the input from the sources located in these regions (the Novaya Zemlya test site, Siberian nuclear plants), while no correlation with the Chernobyl region was observed. Measurements carried out during the Fukushima accident showed a negligible impact of this source with Pu activities by four orders of magnitude lower as compared to the Chernobyl accident. The activity concentration of actinides measured in the integrated sample collected in March-April, 2011 showed a small contribution of Pu with unusual activity and atom ratios indicating the presence of the spent fuel of different origin than that of the Chernobyl accident.

Radionuclide Basics: Plutonium

EPA Pesticide Factsheets

Plutonium (chemical symbol Pu) is a radioactive metal. Plutonium is considered a man-made element. Plutonium-239 is used to make nuclear weapons. Pu-239 and Pu-240 are byproducts of nuclear reactor operations and nuclear bomb explosions.

Determination of origin and intended use of plutonium metal using nuclear forensic techniques.

PubMed

Rim, Jung H; Kuhn, Kevin J; Tandon, Lav; Xu, Ning; Porterfield, Donivan R; Worley, Christopher G; Thomas, Mariam R; Spencer, Khalil J; Stanley, Floyd E; Lujan, Elmer J; Garduno, Katherine; Trellue, Holly R

2017-04-01

Nuclear forensics techniques, including micro-XRF, gamma spectrometry, trace elemental analysis and isotopic/chronometric characterization were used to interrogate two, potentially related plutonium metal foils. These samples were submitted for analysis with only limited production information, and a comprehensive suite of forensic analyses were performed. Resulting analytical data was paired with available reactor model and historical information to provide insight into the materials' properties, origins, and likely intended uses. Both were super-grade plutonium, containing less than 3% 240 Pu, and age-dating suggested that most recent chemical purification occurred in 1948 and 1955 for the respective metals. Additional consideration of reactor modeling feedback and trace elemental observables indicate plausible U.S. reactor origin associated with the Hanford site production efforts. Based on this investigation, the most likely intended use for these plutonium foils was 239 Pu fission foil targets for physics experiments, such as cross-section measurements, etc. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of origin and intended use of plutonium metal using nuclear forensic techniques

DOE PAGES

Rim, Jung H.; Kuhn, Kevin J.; Tandon, Lav; ...

2017-04-01

Nuclear forensics techniques, including micro-XRF, gamma spectrometry, trace elemental analysis and isotopic/chronometric characterization were used to interrogate two, potentially related plutonium metal foils. These samples were submitted for analysis with only limited production information, and a comprehensive suite of forensic analyses were performed. Resulting analytical data was paired with available reactor model and historical information to provide insight into the materials’ properties, origins, and likely intended uses. Both were super-grade plutonium, containing less than 3% 240Pu, and age-dating suggested that most recent chemical purification occurred in 1948 and 1955 for the respective metals. Additional consideration of reactor modelling feedback andmore » trace elemental observables indicate plausible U.S. reactor origin associated with the Hanford site production efforts. In conclusion, based on this investigation, the most likely intended use for these plutonium foils was 239Pu fission foil targets for physics experiments, such as cross-section measurements, etc.« less

PLUTONIUM-CUPFERRON COMPLEX AND METHOD OF REMOVING PLUTONIUM FROM SOLUTION

DOEpatents

Potratz, H.A.

1959-01-13

A method is presented for separating plutonium from fission products present in solutions of neutronirradiated uranium. The process consists in treating such acidic solutions with cupferron so that the cupferron reacts with the plutonium present to form an insoluble complex. This plutonium cupferride precipitates and may then be separated from the solution.

Conversion electron spectrometry of Pu isotopes with a silicon drift detector.

PubMed

Pommé, S; Paepen, J; Peräjärvi, K; Turunen, J; Pöllänen, R

2016-03-01

An electron spectrometry set-up was built at IRMM consisting of a vacuum chamber with a moveable source holder and windowless Peltier-cooled silicon drift detector (SDD). The SDD is well suited for measuring low-energy x rays and electrons emitted from thin radioactive sources with low self-absorption. The attainable energy resolution is better than 0.5keV for electrons of 30keV. It has been used to measure the conversion electron spectra of three plutonium isotopes, i.e. (238)Pu, (239)Pu, (240)Pu, as well as (241)Am (being a decay product of (241)Pu). The obtained mixed x-ray and electron spectra are compared with spectra obtained with a close-geometry set-up using another SDD in STUK and spectra measured with a Si(Li) detector at IRMM. The potential of conversion electron spectrometry for isotopic analysis of mixed plutonium samples is investigated. With respect to the (240)Pu/(239)Pu isotopic ratio, the conversion electron peaks of both isotopes are more clearly separated than their largely overlapping peaks in alpha spectra. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudisill, T.S.

1999-08-11

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 precipitationmore » 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

PRODUCTION OF PLUTONIUM METAL

DOEpatents

Lyon, W.L.; Moore, R.H.

1961-01-17

A process is given for producing plutonium metal by the reduction of plutonium chloride, dissolved in alkali metal chloride plus or minus aluminum chloride, with magnesium or a magnesium-aluminum alloy at between 700 and 800 deg C and separating the plutonium or plutonium-aluminum alloy formed from the salt.

Measurements of plutonium, 237Np, and 137Cs in the BCR 482 lichen reference material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lavelle, Kevin B.; Miller, Jeffrey L.; Hanson, Susan K.

Select anthropogenic radionuclides were measured in lichen reference material, BCR 482. This material was originally collected in Axalp, Switzerland in 1991 and is composed of the epiphytic lichen Pseudevernia furfuracea. Samples from three separate bottles of BCR 482 were analyzed for uranium, neptunium, and plutonium isotopes by inductively coupled plasma mass spectrometry (ICP-MS) and analyzed for cesium-137 by gamma-ray spectrometry. The isotopic composition of the radionuclides measured in BCR 482 suggests contributions from both global fallout resulting from historical nuclear weapons testing and more volatile materials released following the Chernobyl accident.

Measurements of plutonium, 237Np, and 137Cs in the BCR 482 lichen reference material

DOE PAGES

Lavelle, Kevin B.; Miller, Jeffrey L.; Hanson, Susan K.; ...

2015-10-01

Select anthropogenic radionuclides were measured in lichen reference material, BCR 482. This material was originally collected in Axalp, Switzerland in 1991 and is composed of the epiphytic lichen Pseudevernia furfuracea. Samples from three separate bottles of BCR 482 were analyzed for uranium, neptunium, and plutonium isotopes by inductively coupled plasma mass spectrometry (ICP-MS) and analyzed for cesium-137 by gamma-ray spectrometry. The isotopic composition of the radionuclides measured in BCR 482 suggests contributions from both global fallout resulting from historical nuclear weapons testing and more volatile materials released following the Chernobyl accident.

Uncertainty propagation for the coulometric measurement of the plutonium concentration in MOX-PU4.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

This GUM WorkbenchTM propagation of uncertainty is for the coulometric measurement of the plutonium concentration in a Pu standard material (C126) supplied as individual aliquots that were prepared by mass. The C126 solution had been prepared and as aliquoted as standard material. Samples are aliquoted into glass vials and heated to dryness for distribution as dried nitrate. The individual plutonium aliquots were not separated chemically or otherwise purified prior to measurement by coulometry in the F/H Laboratory. Hydrogen peroxide was used for valence adjustment. The Pu assay measurement results were corrected for the interference from trace iron in the solutionmore » measured for assay. Aliquot mass measurements were corrected for air buoyancy. The relative atomic mass (atomic weight) of the plutonium from X126 certoficate was used. The isotopic composition was determined by thermal ionization mass spectrometry (TIMS) for comparison but not used in calculations.« less

Plutonium controversy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richmond, C.R.

1980-01-01

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)

Isotopic insights into biological regulation of zinc in contaminated systems

USGS Publications Warehouse

Wanty, Richard B.; Balistrieri, Laurie S.; Wesner, Jeff S.; Walters, David; Schmidt, Travis S.; Podda, Francesca; De Giudici, G.; Stricker, Craig A.; Kraus, Johanna M.; Lattanzi, Pierfranco; Wolf, Ruth E.; Cidu, R.

2015-01-01

Aquatic organisms use a variety of biogeochemical reactions to regulate essential and non-essential trace metals. Many of these mechanisms can lead to isotopic fractionation, thus measurement of metal isotopes may yield insights into the processes by which organisms respond to metal exposure. We illustrate these concepts with two case studies, one involving an intra- and the other an extra-cellular mechanism of Zn sequestration. In the first study, the mayfly Neocloeon triangulifer was grown in the laboratory, and fed a diet of Zn-doped diatoms at Zn levels exceeding the requirements for normal mayfly life functions. The N. triangulifer larvae consumed the diatoms and retained their Zn isotopic signature. Upon metamorphosis, the subimago life stage lost Zn mass either in the exuvia or by excretion, and the Zn retained was isotopically enriched. Thus, Zn uptake is nonfractionating, but Zn regulation favors the lighter isotope. Thus the Zn remaining in the subimago was isotopically heavier. In the second study, Zn was adsorbed on the cell walls and exopolysaccharide secretions of cyanobacteria, which favored the heavier Zn isotope. Continued adsorption eventually resulted in nucleation and biomineralization of hydrozincite {Zn5(CO3)2(OH)6}. These case studies demonstrate the utility of Zn isotopes to provide insights into how aquatic insects respond to metal exposure.

PRODUCTION OF PLUTONIUM FLUORIDE FROM BISMUTH PHOSPHATE PRECIPITATE CONTAINING PLUTONIUM VALUES

DOEpatents

Brown, H.S.; Bohlmann, E.G.

1961-05-01

A process is given for separating plutonium from fission products present on a bismuth phosphate carrier. The dried carrier is first treated with hydrogen fluoride at between 500 and 600 deg C whereby some fission product fluorides volatilize away from plutonium tetrafluoride, and nonvolatile fission product fluorides are formed then with anhydrous fluorine at between 400 and 500 deg C. Bismuth and plutonium distill in the form of volatile fluorides away from the nonvolatile fission product fluorides. The bismuth and plutonium fluorides are condensed at below 290 deg C.

Analysis of IAEA Environmental Samples for Plutonium and Uranium by ICP/MS in Support Of International Safeguards

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farmer, Orville T.; Olsen, Khris B.; Thomas, May-Lin P.

2008-05-01

A method for the separation and determination of total and isotopic uranium and plutonium by ICP-MS was developed for IAEA samples on cellulose-based media. Preparation of the IAEA samples involved a series of redox chemistries and separations using TRU® resin (Eichrom). The sample introduction system, an APEX nebulizer (Elemental Scientific, Inc), provided enhanced nebulization for a several-fold increase in sensitivity and reduction in background. Application of mass bias (ALPHA) correction factors greatly improved the precision of the data. By combining the enhancements of chemical separation, instrumentation and data processing, detection levels for uranium and plutonium approached high attogram levels.

Plutonium

NASA Astrophysics Data System (ADS)

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

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

PLUTONIUM-HYDROGEN REACTION PRODUCT, METHOD OF PREPARING SAME AND PLUTONIUM POWDER THEREFROM

DOEpatents

Fried, S.; Baumbach, H.L.

1959-12-01

A process is described for forming plutonlum hydride powder by reacting hydrogen with massive plutonium metal at room temperature and the product obtained. The plutonium hydride powder can be converted to plutonium powder by heating to above 200 deg C.

PREPARATION OF PLUTONIUM

DOEpatents

Kolodney, M.

1959-07-01

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

Nature and origin of the nonsulfide zinc deposits in the Sierra Mojada District, Coahuila, Mexico: constraints from regional geology, petrography, and isotope analyses

NASA Astrophysics Data System (ADS)

Kyle, J. Richard; Ahn, Hyein; Gilg, H. Albert

2018-02-01

The Sierra Mojada District comprises multiple types of near-surface mineral concentrations ranging from polymetallic sulfide zones, "nonsulfide Zn" (NSZ) deposits, and a silver-rich Pb carbonate deposit hosted by lower Cretaceous carbonate strata. Hypogene concentrations of Fe-Zn-Pb-Cu-Ag sulfides and sulfosalts are locally preserved and are associated with hydrothermal dolomite and silica. Alteration mineralogy and sulfur isotope data suggest primary Zn-Pb-Ag mineralization from circa 200 °C hydrothermal fluids. The NSZ deposits dominantly consist of smithsonite and hemimorphite associated with local Mn-Fe oxides. The Red Zinc Zone consists of strata-bound zones dominantly of hemimorphite that fills pores in residual and resedimented Fe oxides. The White Zinc Zone shows local dissolution features, including internal sediments interbanded with and cemented by smithsonite. Similar Pb isotopic compositions of smithsonite, hemimorphite, and cerussite to Sierra Mojada galena document that the NSZ deposits originated from polymetallic carbonate-replacement sulfide deposits, with flow of metal-bearing groundwater being controlled by local topography and structural features in this extensional terrane. Oxygen isotope values for Sierra Mojada smithsonite are relatively constant (δ18OVSMOW = 20.9 to 23.3‰) but are unusually low compared to other supergene smithsonites. Using δ18OVSMOW (- 8‰) of modern groundwater at nearby Cuatrociénegas, smithsonite formational temperatures are calculated to have been between 26 to 35 °C. Smithsonite precipitation was favored by near-neutral conditions typical of carbonate terranes, whereas hemimorphite precipitated by reaction with wallrock silica and locally, or episodically, more acidic conditions resulting from sulfide oxidation. Transition to, and stabilization of, the modern desert climate over the past 9000 years from the Late Pleistocene wetter, cooler climate of northern Mexico resulted in episodic drawdown of the water

PLUTONIUM-THORIUM ALLOYS

DOEpatents

Schonfeld, F.W.

1959-09-15

New plutonium-base binary alloys useful as liquid reactor fuel are described. The alloys consist of 50 to 98 at.% thorium with the remainder plutonium. The stated advantages of these alloys over unalloyed plutonium for reactor fuel use are easy fabrication, phase stability, and the accompanying advantuge of providing a means for converting Th/sup 232/ into U/sup 233/.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, K.W.

1979-03-01

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

Studies of Plutonium-238 Production at the High Flux Isotope Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lastres, Oscar; Chandler, David; Jarrell, Joshua J

The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) is a versatile 85 MW{sub th}, pressurized, light water-cooled and -moderated research reactor. The core consists of two fuel elements, an inner fuel element (IFE) and an outer fuel element (OFE), each constructed of involute fuel plates containing high-enriched-uranium (HEU) fuel ({approx}93 wt% {sup 235}U/U) in the form of U{sub 3}O{sub 8} in an Al matrix and encapsulated in Al-6061 clad. An over-moderated flux trap is located in the center of the core, a large beryllium reflector is located on the outside of the core, and two controlmore » elements (CE) are located between the fuel and the reflector. The flux trap and reflector house numerous experimental facilities which are used for isotope production, material irradiation, and cold/thermal neutron scattering. Over the past five decades, the US Department of Energy (DOE) and its agencies have been producing radioisotope power systems used by the National Aeronautics and Space Administration (NASA) for unmanned, long-term space exploration missions. Plutonium-238 is used to power Radioisotope Thermoelectric Generators (RTG) because it has a very long half-life (t{sub 1/2} {approx} 89 yr.) and it generates about 0.5 watts/gram when it decays via alpha emission. Due to the recent shortage and uncertainty of future production, the DOE has proposed a plan to the US Congress to produce {sup 238}Pu by irradiating {sup 237}Np as early as in fiscal year 2011. An annual production rate of 1.5 to 2.0 kg of {sup 238}Pu is expected to satisfy these needs and could be produced in existing national nuclear facilities like HFIR and the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Reactors at the Savannah River Site were used in the past for {sup 238}Pu production but were shut down after the last production in 1988. The nation's {sup 237}Np inventory is currently stored at INL. A plan for producing {sup 238}Pu at US research

Plutonium storage criteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, D.; Ascanio, X.

1996-05-01

The Department of Energy has issued a technical standard for long-term (>50 years) storage and will soon issue a criteria document for interim (<20 years) storage of plutonium materials. The long-term technical standard, {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides,{close_quotes} addresses the requirements for storing metals and oxides with greater than 50 wt % plutonium. It calls for a standardized package that meets both off-site transportation requirements, as well as remote handling requirements from future storage facilities. The interim criteria document, {open_quotes}Criteria for Interim Safe Storage of Plutonium-Bearing Solid Materials{close_quotes}, addresses requirements for storing materials with less thanmore » 50 wt% plutonium. The interim criteria document assumes the materials will be stored on existing sites, and existing facilities and equipment will be used for repackaging to improve the margin of safety.« less

Zinc isotope anomalies in Allende meteorite inclusions

NASA Technical Reports Server (NTRS)

Loss, R. D.; Lugmair, G. W.

1990-01-01

The isotopic compositions of Zn, Cr, Ti, and Ca have been measured in a number of CAIs from the Allende meteorite. The aim was to test astrophysical models which predict large excesses of Zn-66 to accompany excesses in the neutron-rich isotopes of Ca, Ti, Cr, and Ni. Some of the CAIs show clearly resolved but small excesses for Zn-66 which are at least an order of magnitude smaller than predicted. This result may simply reflect the volatility and chemical behavior of Zn as compared to the other (more refractory) anomalous elements found in these samples. Alternatively, revision of parameters and assumptions used for the model calculations may be required.

PLUTONIUM-ZIRCONIUM ALLOYS

DOEpatents

Schonfeld, F.W.; Waber, J.T.

1960-08-30

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

Method for dissolving plutonium dioxide

DOEpatents

Tallent, Othar K.

1978-01-01

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

Selection of Russian Plutonium Beryllium Sources for Inclusion in the Nuclear Mateirals Information Program Archive

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narlesky, Joshua E; Padilla, Dennis D; Watts, Joe

2009-01-01

developed so that the largest sources that are representative of the collection are included. One representative source was chosen for every 20 sources in the collection, and effort was made to preserve sources unique to the collection. In total, four representative sources and five unique sources were selected for the archive. The archive samples contain 40 grams of plutonium with an isotopic composition similar to that of weapon grade material and three grams of plutonium with an isotopic composition similar to that of reactor grade plutonium.« less

Dual-isotope method for determination of human zinc absorption: the use of a test meal of turkey meat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flanagan, P.R.; Cluett, J.; Chamberlain, M.J.

The percentage of /sup 65/Zn taken up (absorbed) from extrinsically labeled turkey meat was calculated from the amounts of /sup 65/Zn and a nonabsorbed /sup 51/Cr marker present in the body or in a single stool specimen after 1-2 d. /sup 51/CrCl/sub 3/ proved to be a suitable marker for unabsorbed /sup 65/Zn and so the early determination of /sup 65/Zn absorption was possible. With stool counting, /sup 65/Zn absorption data from first stool samples after 1-2 d were accurate as judged by correlation with the amount of /sup 65/Zn in the body 7-10 d later (retention); results from subsequentmore » stools gave lower absorption values due to the early excretion of some absorbed /sup 65/Zn. The dual-isotope method gave reproducible results when four successive tests of zinc absorption were carried out in a group of six subjects. The average (mean +/- SD) /sup 65/Zn absorption from turkey meals containing 31 mumol (2 mg) and 46 mumol (3 mg) of zinc was 39 +/- 8% and 29 +/- 6%, respectively, measured by stool counting; /sup 65/Zn absorption and retention correlated well in both studies. A series of different beverages was given in place of water with the turkey meal. Orange juice significantly reduced /sup 65/Zn absorption and milk also showed this tendency, but tea, whiskey, wine or beer had no significant effect on the absorption of /sup 65/Zn from the turkey meal. In groups of subjects the mean ratio of /sup 65/Zn absorption from extrinsically labeled turkey meat on two occasions (1.06) was not significantly different from that of the absorption of extrinsic to intrinsic /sup 65/Zn labels (1.16). The dual-isotope technique with either stool or body counting is suitable for the rapid determination of /sup 65/Zn absorption from extrinsically labeled turkey within 2 d.« less

Improved precision and accuracy in quantifying plutonium isotope ratios by RIMS

DOE PAGES

Isselhardt, B. H.; Savina, M. R.; Kucher, A.; ...

2015-09-01

Resonance ionization mass spectrometry (RIMS) holds the promise of rapid, isobar-free quantification of actinide isotope ratios in as-received materials (i.e. not chemically purified). Recent progress in achieving this potential using two Pu test materials is presented. RIMS measurements were conducted multiple times over a period of two months on two different Pu solutions deposited on metal surfaces. Measurements were bracketed with a Pu isotopic standard, and yielded absolute accuracies of the measured 240Pu/ 239Pu ratios of 0.7% and 0.58%, with precisions (95% confidence intervals) of 1.49% and 0.91%. In conclusion, the minor isotope 238Pu was also quantified despite the presencemore » of a significant quantity of 238U in the samples.« less

Plutonium radiation surrogate

DOEpatents

Frank, Michael I [Dublin, CA

2010-02-02

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.

The effect of the composition of plutonium loaded on the reactivity change and the isotopic composition of fuel produced in a fast reactor

NASA Astrophysics Data System (ADS)

Blandinskiy, V. Yu.

2014-12-01

This paper presents the results of a numerical investigation into burnup and breeding of nuclides in metallic fuel consisting of a mixture of plutonium and depleted uranium in a fast reactor with sodium coolant. The feasibility of using plutonium contained in spent nuclear fuel from domestic thermal reactors and weapons-grade plutonium is discussed. It is shown that the largest production of secondary fuel and the least change in the reactivity over the reactor lifetime can be achieved when employing plutonium contained in spent nuclear fuel from a reactor of the RBMK-1000 type.

Continuous plutonium dissolution apparatus

DOEpatents

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

1974-02-26

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

Plutonium weathering on Johnston Atoll

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, S.E.; Bates, J.K.; Buck, E.C.

1995-12-31

Johnston Atoll was contaminated with transuranic elements, particularly plutonium, by atmospheric nuclear weapons tests and aborted nuclear devices. Initial cleanup operations and and an extensive soil remediation program were performed. However, many areas contained a low-level continuum of activity, and subsurface contamination has been detected. Discrete hot particles and contaminated soil were characterized to determine whether the spread of activity was caused by weathering. Analytical techniques included gamma spectrometry, alpha spectrometry, and inductively coupled plasma-mass spectrometry to determine transuranic elemental and isotopic composition. Ultrafiltration and small-particle handling techniques were employed to isolate individual particles. Optical microscopy, scanning electron microscopy, analyticalmore » transmission electron microscopy, energy dispersive X-ray spectroscopy, and electron energy loss spectroscopy were used to characterize individual particles. Analyses of the hot particles showed that they are aborted nuclear warhead fragments that been melted and weathered in the presence of water and CaCO{sub 3}. It was concluded that the formation of aqueous ionic (Pu/Am)-CO{sub 3} coordinated complexes, during environmental exposure to large volumes of rainwater and carbonate-satured seawater, enhanced the solubility of transuranic elements. The (Pu/Am)-CO{sub 3} complexes sorbed onto colloidal CaCO{sub 3} and coral soil surfaces as they were exposed to rain and seawater. This mechanism led to greater dispersal of plutonium and americium than would be expected by physical transport of discrete hot particles alone.« less

Plutonium dissolution process

DOEpatents

Vest, Michael A.; Fink, Samuel D.; Karraker, David G.; Moore, Edwin N.; Holcomb, H. Perry

1996-01-01

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.

METHOD OF SEPARATING PLUTONIUM

DOEpatents

Heal, H.G.

1960-02-16

BS>A method of separating plutonium from aqueous nitrate solutions of plutonium, uranium. and high beta activity fission products is given. The pH of the aqueous solution is adjusted between 3.0 to 6.0 with ammonium acetate, ferric nitrate is added, and the solution is heated to 80 to 100 deg C to selectively form a basic ferric plutonium-carrying precipitate.

PLUTONIUM-CERIUM ALLOY

DOEpatents

Coffinberry, A.S.

1959-01-01

An alloy is presented for use as a reactor fuel. The binary alloy consists essentially of from about 5 to 90 atomic per cent cerium and the balance being plutonium. A complete phase diagram for the cerium--plutonium system is given.

METHOD OF MAKING PLUTONIUM DIOXIDE

DOEpatents

Garner, C.S.

1959-01-13

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

Fractionation of metal stable isotopes by higher plants

USGS Publications Warehouse

Von Blanckenburg, F.; Von Wiren, N.; Guelke, M.; Weiss, D.J.; Bullen, T.D.

2009-01-01

Higher plants induce chemical reactions in the rhizosphere, facilitating metal uptake by roots. Fractionation of the isotopes in nutrients such as calcium, iron, magnesium, and zinc produces a stable isotope composition in the plants that generally differs from that of the growth medium. Isotope fractionation also occurs during transport of the metals within most plants, but its extent depends on plant species and on the metal, in particular, on the metal's redox state and what ligand it is bound to. The metal stable isotope variations observed in plants create an isotope signature of life at the Earth's surface, contributing substantially to our understanding of metal cycling processes in the environment and in individual organisms.

METHOD OF PRODUCING PLUTONIUM TETRAFLUORIDE

DOEpatents

Tolley, W.B.; Smith, R.C.

1959-12-15

A process is presented for preparing plutonium tetrafluoride from plutonium(IV) oxalate. The oxalate is dried and decomposed at about 300 deg C to the dioxide, mixed with ammonium bifluoride, and the mixture is heated to between 50 and 150 deg C whereby ammonium plutonium fluoride is formed. The ammonium plutonium fluoride is then heated to about 300 deg C for volatilization of ammonium fluoride. Both heating steps are preferably carried out in an inert atmosphere.

Metamorphosis affects metal concentrations and isotopic signatures in a mayfly (Baetis tricaudatus): Implications for the aquatic-terrestrial transfer of metals

USGS Publications Warehouse

Wesner, Jeff S.; Walters, David; Schmidt, Travis S.; Kraus, Johanna M.; Stricker, Craig A.; Clements, William H.; Wolf, Ruth E.

2017-01-01

Insect metamorphosis often results in substantial chemical changes that can alter contaminant concentrations and fractionate isotopes. We exposed larval mayflies (Baetis tricaudatus) and their food (periphyton) to an aqueous zinc gradient (3-340 µg Zn/l) and measured zinc concentrations at different stages of metamorphosis: larval, subimago, and imago. We also measured changes in stable isotopes (δ15N and δ13C) in unexposed mayflies. Larval zinc concentrations were positively related to aqueous zinc, increasing 9-fold across the exposure gradient. Adult zinc concentrations were also positively related to aqueous zinc, but were 7-fold lower than larvae. This relationship varied according to adult substage and sex. Tissue concentrations in female imagoes were not related to exposure concentrations, but the converse was true for all other stage-by-sex combinations. Metamorphosis also increased δ15N by ~0.8‰, but not δ13C. Thus, the main effects of metamorphosis on insect chemistry were large declines in zinc concentrations coupled with increased δ15N signatures. For zinc, this change was largely consistent across the aqueous exposure gradient. However, differences among sexes and stages suggest that caution is warranted when using nitrogen isotopes or metal concentrations measured in one insect stage (e.g. larvae) to assess risk to wildlife that feed on subsequent life stages (e.g. adults).

Metamorphosis Affects Metal Concentrations and Isotopic Signatures in a Mayfly (Baetis tricaudatus): Implications for the Aquatic-Terrestrial Transfer of Metals.

PubMed

Wesner, Jeff S; Walters, David M; Schmidt, Travis S; Kraus, Johanna M; Stricker, Craig A; Clements, William H; Wolf, Ruth E

2017-02-21

Insect metamorphosis often results in substantial chemical changes that can alter contaminant concentrations and fractionate isotopes. We exposed larval mayflies (Baetis tricaudatus) and their food (periphyton) to an aqueous zinc gradient (3-340 μg Zn/l) and measured zinc concentrations at different stages of metamorphosis: larval, subimago, and imago. We also measured changes in stable isotopes (δ 15 N and δ 13 C) in unexposed mayflies. Larval zinc concentrations were positively related to aqueous zinc, increasing 9-fold across the exposure gradient. Adult zinc concentrations were also positively related to aqueous zinc, but were 7-fold lower than larvae. This relationship varied according to adult substage and sex. Tissue concentrations in female imagoes were not related to exposure concentrations, but the converse was true for all other stage-by-sex combinations. Metamorphosis also increased δ 15 N by ∼0.8‰, but not δ 13 C. Thus, the main effects of metamorphosis on insect chemistry were large declines in zinc concentrations coupled with increased δ 15 N signatures. For zinc, this change was largely consistent across the aqueous exposure gradient. However, differences among sexes and stages suggest that caution is warranted when using nitrogen isotopes or metal concentrations measured in one insect stage (e.g., larvae) to assess risk to wildlife that feed on subsequent life stages (e.g., adults).

A Zn isotope perspective on the rise of continents.

PubMed

Pons, M-L; Fujii, T; Rosing, M; Quitté, G; Télouk, P; Albarède, F

2013-05-01

Zinc isotope abundances are fairly constant in igneous rocks and shales and are left unfractionated by hydrothermal processes at pH < 5.5. For that reason, Zn isotopes in sediments can be used to trace the changing chemistry of the hydrosphere. Here, we report Zn isotope compositions in Fe oxides from banded iron formations (BIFs) and iron formations of different ages. Zinc from early Archean samples is isotopically indistinguishable from the igneous average (δ(66) Zn ~0.3‰). At 2.9-2.7 Ga, δ(66) Zn becomes isotopically light (δ(66) Zn < 0‰) and then bounces back to values >1‰ during the ~2.35 Ga Great Oxygenation Event. By 1.8 Ga, BIF δ(66) Zn has settled to the modern value of FeMn nodules and encrustations (~0.9‰). The Zn cycle is largely controlled by two different mechanisms: Zn makes strong complexes with phosphates, and phosphates in turn are strongly adsorbed by Fe hydroxides. We therefore review the evidence that the surface geochemical cycles of Zn and P are closely related. The Zn isotope record echoes Sr isotope evidence, suggesting that erosion starts with the very large continental masses appearing at ~2.7 Ga. The lack of Zn fractionation in pre-2.9 Ga BIFs is argued to reflect the paucity of permanent subaerial continental exposure and consequently the insignificant phosphate input to the oceans and the small output of biochemical sediments. We link the early decline of δ(66) Zn between 3.0 and 2.7 Ga with the low solubility of phosphate in alkaline groundwater. The development of photosynthetic activity at the surface of the newly exposed continents increased the oxygen level in the atmosphere, which in turn triggered acid drainage and stepped up P dissolution and liberation of heavy Zn into the runoff. Zinc isotopes provide a new perspective on the rise of continents, the volume of carbonates on continents, changing weathering conditions, and compositions of the ocean through time. © 2013 Blackwell Publishing Ltd.

The study of trace metal absoption using stable isotopes and mass spectrometry

NASA Astrophysics Data System (ADS)

Fennessey, P. V.; Lloyd-Kindstrand, L.; Hambidge, K. M.

1991-12-01

The absorption and excretion of zinc stable isotopes have been followed in more than 120 human subjects. The isotope enrichment determinations were made using a standard VG 7070E HF mass spectrometer. A fast atom gun (FAB) was used to form the ions from a dry residue on a pure silver probe tip. Isotope ratio measurements were found to have a precision of better than 2% (relative standard deviation) and required a sample size of 1-5 [mu]g. The average true absorption of zinc was found to be 73 ± 12% (2[sigma]) when the metal was taken in a fasting state. This absorption figure was corrected for tracer that had been absorbed and secreted into the gastrointestinal (GI) tract over the time course of the study. The average time for a majority of the stable isotope tracer to pass through the GI tract was 4.7 ± 1.9 (2[sigma]) days.

PLUTONIUM ELECTROREFINING CELLS

DOEpatents

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

1963-07-16

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

PLUTONIUM SEPARATION METHOD

DOEpatents

Beaufait, L.J. Jr.; Stevenson, F.R.; Rollefson, G.K.

1958-11-18

The recovery of plutonium ions from neutron irradiated uranium can be accomplished by bufferlng an aqueous solutlon of the irradiated materials containing tetravalent plutonium to a pH of 4 to 7, adding sufficient acetate to the solution to complex the uranyl present, adding ferric nitrate to form a colloid of ferric hydroxide, plutonlum, and associated fission products, removing and dissolving the colloid in aqueous nitric acid, oxldizlng the plutonium to the hexavalent state by adding permanganate or dichromate, treating the resultant solution with ferric nitrate to form a colloid of ferric hydroxide and associated fission products, and separating the colloid from the plutonlum left in solution.

PROCESS FOR SEPARATING PLUTONIUM FROM IMPURITIES

DOEpatents

Wahl, A.C.

1957-11-12

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

Method of separating thorium from plutonium

DOEpatents

Clifton, David G.; Blum, Thomas W.

1984-01-01

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

Tags to Track Illicit Uranium and Plutonium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haire, M. Jonathan; Forsberg, Charles W.

2007-07-01

With the expansion of nuclear power, it is essential to avoid nuclear materials from falling into the hands of rogue nations, terrorists, and other opportunists. This paper examines the idea of detection and attribution tags for nuclear materials. For a detection tag, it is proposed to add small amounts [about one part per billion (ppb)] of {sup 232}U to enriched uranium to brighten its radioactive signature. Enriched uranium would then be as detectable as plutonium and thus increase the likelihood of intercepting illicit enriched uranium. The use of rare earth oxide elements is proposed as a new type of 'attribution'more » tag for uranium and thorium from mills, uranium and plutonium fuels, and other nuclear materials. Rare earth oxides are chosen because they are chemically compatible with the fuel cycle, can survive high-temperature processing operations in fuel fabrication, and can be chosen to have minimal neutronic impact within the nuclear reactor core. The mixture of rare earths and/or rare earth isotopes provides a unique 'bar code' for each tag. If illicit nuclear materials are recovered, the attribution tag can identify the source and lot of nuclear material, and thus help police reduce the possible number of suspects in the diversion of nuclear materials based on who had access. (authors)« less

Improved sample utilization in thermal ionization mass spectrometry isotope ratio measurements: refined development of porous ion emitters for nuclear forensic applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baruzzini, Matthew Louis

The precise and accurate determination of isotopic composition in nuclear forensic samples is vital for assessing origin, intended use and process history. Thermal ionization mass spectrometry (TIMS) is widely accepted as the gold standard for high performance isotopic measurements and has long served as the workhorse in the isotopic ratio determination of nuclear materials. Nuclear forensic and safeguard specialists have relied heavily on such methods for both routine and atypical e orts. Despite widespread use, TIMS methods for the assay of actinide systems continue to be hindered by poor ionization e ciency, often less than tenths of a percent; themore » majority of a sample is not measured. This represents a growing challenge in addressing nextgeneration nuclear detection needs by limiting the ability to analyze ultratrace quantities of high priority elements that could potentially provide critical nuclear forensic signatures. Porous ion emitter (PIE) thermal ion sources were developed in response to the growing need for new TIMS ion source strategies for improved ionization e ciency, PIEs have proven to be simple to implement, straightforward approach to boosting ion yield. This work serves to expand the use of PIE techniques for the analysis of trace quantities of plutonium and americium. PIEs exhibited superior plutonium and americium ion yields when compared to direct lament loading and the resin bead technique, one of the most e cient methods for actinide analysis, at similar mass loading levels. Initial attempts at altering PIE composition for the analysis of plutonium proved to enhance sample utilization even further. Preliminary investigations of the instrumental fractionation behavior of plutonium and uranium analyzed via PIE methods were conducted. Data collected during these initial trial indicate that PIEs fractionate in a consistent, reproducible manner; a necessity for high precision isotope ratio measurements. Ultimately, PIEs methods were

Progress on plutonium stabilization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurt, D.

1996-05-01

The Defense Nuclear Facilities Safety Board has safety oversight responsibility for most of the facilities where unstable forms of plutonium are being processed and packaged for interim storage. The Board has issued recommendations on plutonium stabilization and has has a considerable influence on DOE`s stabilization schedules and priorities. The Board has not made any recommendations on long-term plutonium disposition, although it may get more involved in the future if DOE develops plans to use defense nuclear facilities for disposition activities.

PREPARATION OF PLUTONIUM TRIFLUORIDE

DOEpatents

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

1961-07-11

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

ELECTRODEPOSITION OF PLUTONIUM

DOEpatents

Wolter, F.J.

1957-09-10

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

Excess Weapons Plutonium Immobilization in Russia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jardine, L.; Borisov, G.B.

2000-04-15

The joint goal of the Russian work is to establish a full-scale plutonium immobilization facility at a Russian industrial site by 2005. To achieve this requires that the necessary engineering and technical basis be developed in these Russian projects and the needed Russian approvals be obtained to conduct industrial-scale immobilization of plutonium-containing materials at a Russian industrial site by the 2005 date. This meeting and future work will provide the basis for joint decisions. Supporting R&D projects are being carried out at Russian Institutes that directly support the technical needs of Russian industrial sites to immobilize plutonium-containing materials. Special R&Dmore » on plutonium materials is also being carried out to support excess weapons disposition in Russia and the US, including nonproliferation studies of plutonium recovery from immobilization forms and accelerated radiation damage studies of the US-specified plutonium ceramic for immobilizing plutonium. This intriguing and extraordinary cooperation on certain aspects of the weapons plutonium problem is now progressing well and much work with plutonium has been completed in the past two years. Because much excellent and unique scientific and engineering technical work has now been completed in Russia in many aspects of plutonium immobilization, this meeting in St. Petersburg was both timely and necessary to summarize, review, and discuss these efforts among those who performed the actual work. The results of this meeting will help the US and Russia jointly define the future direction of the Russian plutonium immobilization program, and make it an even stronger and more integrated Russian program. The two objectives for the meeting were to: (1) Bring together the Russian organizations, experts, and managers performing the work into one place for four days to review and discuss their work with each other; and (2) Publish a meeting summary and a proceedings to compile reports of all the

Method of separating thorium from plutonium

DOEpatents

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

A method of chemically separating plutonium from thorium is claimed. 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.

Method of separating thorium from plutonium

DOEpatents

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

1984-07-10

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.

Bioavailability of zinc oxide added to corn tortilla is similar to that of zinc sulfate and is not affected by simultaneous addition of iron

PubMed Central

Rosado, Jorge L.; Díaz, Margarita; Muñoz, Elsa; Westcott, Jamie L.; González, Karla E.; Krebs, Nancy F.; Caamaño, María C.; Hambidge, Michael

2013-01-01

Background Corn tortilla is the staple food of Mexico and its fortification with zinc, iron, and other micronutrients is intended to reduce micronutrient deficiencies. However, no studies have been performed to determine the relative amount of zinc absorbed from the fortified product and whether zinc absorption is affected by the simultaneous addition of iron. Objective To compare zinc absorption from corn tortilla fortified with zinc oxide versus zinc sulfate and to determine the effect of simultaneous addition of two doses of iron on zinc bioavailability. Methods A randomized, double-blind, crossover design was carried out in two phases. In the first phase, 10 adult women received corn tortillas with either 20 mg/kg of zinc oxide added, 20 mg/kg of zinc sulfate added, or no zinc added. In the second phase, 10 adult women received corn tortilla with 20 mg/kg of zinc oxide added and either with no iron added or with iron added at one of two different levels. Zinc absorption was measured by the stable isotope method. Results The mean (± SEM) fractional zinc absorption from unfortified tortilla, tortilla fortified with zinc oxide, and tortilla fortified with zinc sulfate did not differ among treatments: 0.35 ± 0.07, 0.36 ± 0.05, and 0.37 ± 0.07, respectively. The three treatment groups with 0, 30, and 60 mg/kg of added iron had similar fractional zinc absorption (0.32 ± 0.04, 0.33 ± 0.02, and 0.32 ± 0.05, respectively) and similar amounts of zinc absorbed (4.8 ± 0.7, 4.5 ± 0.3, and 4.8 ± 0.7 mg/day, respectively). Conclusions Since zinc oxide is more stable and less expensive and was absorbed equally as well as zinc sulfate, we suggest its use for corn tortilla fortification. Simultaneous addition of zinc and iron to corn tortilla does not modify zinc bioavailability at iron doses of 30 and 60 mg/kg of corn flour. PMID:23424892

Zinc allocation and re-allocation in rice.

PubMed

Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E L; Struik, Paul C

2014-01-01

Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Two solution culture experiments using (70)Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg(-1) dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement.

Zinc allocation and re-allocation in rice

PubMed Central

Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E. L.; Struik, Paul C.

2014-01-01

Aims: Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Methods: Two solution culture experiments using 70Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. Results: A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg−1 dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. Conclusions: In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement. PMID:24478788

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caviness, Michael L; Mann, Paul T; Yoshimura, Richard H

2010-01-01

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.

Tracing fluid transfer across subduction zones using iron and zinc stable isotopes

NASA Astrophysics Data System (ADS)

Williams, H. M.; Debret, B.; Pons, M. L.; Bouilhol, P.

2016-12-01

In subduction zones, serpentinite devolatilization within the downgoing slab and the fluids released play a fundamental role in volatile transfer as well as the redox evolution of the sub-arc mantle. Constraining subduction-related serpentinite devolatilisation is essential in order to better understand of the nature and composition of slab-derived fluids and fluid/rock interactions. Fe and Zn stable isotopes can trace fluid composition and speciation as isotope partitioning is driven by changes in oxidation state, coordination, and bonding environment. In the case of serpentinite devolatilisation, Fe isotope fractionation should reflect changes in Fe redox state and the formation of Fe-Cl- and SO42- complexes (Hill et al., GCA 2010); Zn isotope fractionation should be sensitive to complexation with CO32-, HS- and SO42- anions (Fujii et al., GCA 2011). We targeted samples from Western Alps ophiolite complexes, interpreted as remnants of serpentinized oceanic lithosphere metamorphosed and devolatilized during subduction (Hattori and Guillot, G3 2007; Debret et al., Chem. Geol. 2013). A striking negative correlation is present between bulk serpentinite Fe isotope composition and Fe3+/Fetot, with the highest grade samples displaying the heaviest Fe isotope compositions and lowest Fe3+/Fetot (Debret et al., Geology, 2016). The same samples also display a corresponding variation in Zn isotopes, with the highest grade samples displaying isotopically light compositions (Pons et al., in revision). The negative correlation between Fe and Zn isotopes and decrease in Fe3+/Fetot can explained by serpentinite sulfide breakdown and the release of fluids enriched in isotopically light Fe and heavy Zn sulphate complexes. The migration of these SOX-bearing fluids from the slab to the slab-mantle interface or mantle wedge has important implications for the redox evolution of the sub-arc mantle and the transport of metals from the subducting slab.

ADSORPTION-BISMUTH PHOSPHATE METHOD FOR SEPARATING PLUTONIUM

DOEpatents

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

1960-06-28

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

Plutonium Isotopes (239-241Pu) Dissolved in Pacific Ocean Waters Detected by Accelerator Mass Spectrometry: No Effects of the Fukushima Accident Observed.

PubMed

Hain, Karin; Faestermann, Thomas; Fimiani, Leticia; Golser, Robin; Gómez-Guzmán, José Manuel; Korschinek, Gunther; Kortmann, Florian; Lierse von Gostomski, Christoph; Ludwig, Peter; Steier, Peter; Tazoe, Hirofumi; Yamada, Masatoshi

2017-02-21

The concentration of plutonium (Pu) and the isotopic ratios of 240 Pu to 239 Pu and 241 Pu to 239 Pu were determined by accelerator mass spectrometry (AMS) in Pacific Ocean water samples (20 L each) collected in late 2012. The isotopic Pu ratios are important indicators of different contamination sources and were used to identify a possible release of Pu into the ocean by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. In particular, 241 Pu is a well-suited indicator for a recent entry of Pu because 241 Pu from fallout of nuclear weapon testings has already significantly decayed. A total of 10 ocean water samples were prepared at the Radiochemie München of the TUM and analyzed at the Vienna Environmental Research Laboratory (VERA). Several samples showed a slightly elevated 240 Pu/ 239 Pu ratio of up to 0.22 ± 0.02 compared to global fallout ( 240 Pu/ 239 Pu = 0.180 ± 0.007), whereas all measured 241 Pu-to- 239 Pu ratios were consistent with nuclear weapon fallout ( 241 Pu/ 239 Pu < 2.4 × 10 -3 ), which means that no impact from the Fukushima accident was detected. From the average 241 Pu-to- 239 Pu ratio of 8 -2 +3 ×10 -4 at a sampling station located at a distance of 39.6 km to FDNPP, the 1-σ upper limit for the FDNPP contribution to the 239 Pu inventory in the water column was estimated to be 0.2%. Pu, with the signature of weapon-grade Pu was found in a single sample collected around 770 km off the west coast of the United States.

Plutonium inventories for stabilization and stabilized materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, A.K.

1996-05-01

The objective of the breakout session was to identify characteristics of materials containing plutonium, the need to stabilize these materials for storage, and plans to accomplish the stabilization activities. All current stabilization activities are driven by the Defense Nuclear Facilities Safety Board Recommendation 94-1 (May 26, 1994) and by the recently completed Plutonium ES&H Vulnerability Assessment (DOE-EH-0415). The Implementation Plan for accomplishing stabilization of plutonium-bearing residues in response to the Recommendation and the Assessment was published by DOE on February 28, 1995. This Implementation Plan (IP) commits to stabilizing problem materials within 3 years, and stabilizing all other materials withinmore » 8 years. The IP identifies approximately 20 metric tons of plutonium requiring stabilization and/or repackaging. A further breakdown shows this material to consist of 8.5 metric tons of plutonium metal and alloys, 5.5 metric tons of plutonium as oxide, and 6 metric tons of plutonium as residues. Stabilization of the metal and oxide categories containing greater than 50 weight percent plutonium is covered by DOE Standard {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides{close_quotes} December, 1994 (DOE-STD-3013-94). This standard establishes criteria for safe storage of stabilized plutonium metals and oxides for up to 50 years. Each of the DOE sites and contractors with large plutonium inventories has either started or is preparing to start stabilization activities to meet these criteria.« less

Plutonium isotopes in the atmosphere of Central Europe: Isotopic composition and time evolution vs. circulation factors.

PubMed

Kierepko, Renata; Mietelski, Jerzy W; Ustrnul, Zbigniew; Anczkiewicz, Robert; Wershofen, Herbert; Holgye, Zoltan; Kapała, Jacek; Isajenko, Krzysztof

2016-11-01

This paper reports evidence of Pu isotopes in the lower part of the troposphere of Central Europe. The data were obtained based on atmospheric aerosol fraction samples collected from four places in three countries (participating in the informal European network known as the Ring of Five (Ro5)) forming a cell with a surface area of about 200,000km(2). We compared our original data sets from Krakow (Poland, 1990-2007) and Bialystok (Poland, 1991-2007) with the results from two other locations, Prague (Czech Republic; 1997-2004) and Braunschweig (Germany; 1990-2003) to find time evolution of the Pu isotopes. The levels of the activity concentration for (238)Pu and for ((239+240))Pu were estimated to be a few and some tens of nBqm(-3), respectively. However, we also noted some results were much higher (even about 70 times higher) than the average concentration of (238)Pu in the atmosphere. The achieved complex data sets were used to test a new approach to the problem of solving mixing isotopic traces from various sources (here up to three) in one sample. Results of our model, supported by mesoscale atmospheric circulation parameters, suggest that Pu from nuclear weapon accidents or tests and nuclear burnt-up fuel are present in the air. Copyright © 2016 Elsevier B.V. All rights reserved.

PROCESS OF SEPARATING PLUTONIUM FROM URANIUM

DOEpatents

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

1958-09-01

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

Assessment of Non-traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear Activities. Annual Report 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biegalski, Steven R.; Buchholz, Bruce A.

2011-08-24

The objective of this work is to identify isotopic ratios suitable for analysis via mass spectrometry that distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Methods will also be determined to distinguish the above from medical and industrial radionuclide sources. Mass spectrometry systems will be identified that are suitable for field measurement of such isotopes in an expedient manner.

PROCESS FOR THE RECOVERY OF PLUTONIUM

DOEpatents

Ritter, D.M.

1959-01-13

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

Real-time monitoring of plutonium content in uranium-plutonium alloys

DOEpatents

Li, Shelly Xiaowei; Westphal, Brian Robert; Herrmann, Steven Douglas

2015-09-01

A method and device for the real-time, in-situ monitoring of Plutonium content in U--Pu Alloys comprising providing a crucible. The crucible has an interior non-reactive to a metallic U--Pu alloy within said interior of said crucible. The U--Pu alloy comprises metallic uranium and plutonium. The U--Pu alloy is heated to a liquid in an inert or reducing atmosphere. The heated U--Pu alloy is then cooled to a solid in an inert or reducing atmosphere. As the U--Pu alloy is cooled, the temperature of the U--Pu alloy is monitored. A solidification temperature signature is determined from the monitored temperature of the U--Pu alloy during the step of cooling. The amount of Uranium and the amount of Plutonium in the U--Pu alloy is then determined from the determined solidification temperature signature.

Using Biomolecules to Separate Plutonium

NASA Astrophysics Data System (ADS)

Gogolski, Jarrod

Used nuclear fuel has traditionally been treated through chemical separations of the radionuclides for recycle or disposal. This research considers a biological approach to such separations based on a series of complex and interdependent interactions that occur naturally in the human body with plutonium. These biological interactions are mediated by the proteins serum transferrin and the transferrin receptor. Transferrin to plutonium in vivo and can deposit plutonium into cells after interacting with the transferrin receptor protein at the cell surface. Using cerium as a non-radioactive surrogate for plutonium, it was found that cerium(IV) required multiple synergistic anions to bind in the N-lobe of the bilobal transferrin protein, creating a conformation of the cerium-loaded protein that would be unable to interact with the transferrin receptor protein to achieve a separation. The behavior of cerium binding to transferrin has contributed to understanding how plutonium(IV)-transferrin interacts in vivo and in biological separations.

SEPARATION OF PLUTONIUM HYDROXIDE FROM BISMUTH HYDROXIDE

DOEpatents

Watt, G.W.

1958-08-19

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

Pyrochemical process for extracting plutonium from an electrolyte salt

DOEpatents

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

1982-09-20

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

Pyrochemical process for extracting plutonium from an electrolyte salt

DOEpatents

Mullins, Lawrence J.; Christensen, Dana C.

1984-01-01

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

PROCESS OF PRODUCING SHAPED PLUTONIUM

DOEpatents

Anicetti, R.J.

1959-08-11

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

PLUTONIUM COMPOUNDS AND PROCESS FOR THEIR PREPARATION

DOEpatents

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

1958-01-01

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

TERNARY ALLOY-CONTAINING PLUTONIUM

DOEpatents

Waber, J.T.

1960-02-23

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

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

PubMed

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

2003-07-20

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

Plutonium recovery from organic materials

DOEpatents

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

1973-12-11

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

Siegfried S. Hecker, Plutonium, and Nonproliferation

Science.gov Websites

controversy involving the stability of certain structures (or phases) in plutonium alloys near equilibrium Cold War is Over. What Now?, DOE Technical Report, April, 1995 6th US-Russian Pu Science Workshop * Aging of Plutonium and Its Alloys * A Tale of Two Diagrams * Plutonium and Its Alloys-From Atoms to

NON-CORROSIVE PLUTONIUM FUEL SYSTEMS

DOEpatents

Coffinberry, A.S.; Waber, J.T.

1962-10-23

An improved plutonium reactor liquid fuel is described for utilization in a nuclear reactor having a tantalum fuel containment vessel. The fuel consists of plutonium and a diluent such as iron, cobalt, nickel, cerium, cerium-- iron, cerium--cobalt, cerium--nickel, and cerium--copper, and an additive of carbon and silicon. The carbon and silicon react with the tantalum container surface to form a coating that is self-healing and prevents the corrosive action of liquid plutonium on the said tantalum container. (AEC)

Search for Plutonium Salt Deposits in the Plutonium Extraction Batteries of the Marcoule Plant; RECHERCHE DE DEPOTS DE SELS DE PLUTONIUM DANS LES BATTERIES D'EXTRACTION DU PLUTONIUM DE L'USINE DE MARCOULE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouzigues, H.; Reneaud, J.-M.

1963-01-01

A method and a special apparatus are described which make it possible to detach the insoluble plutonium salt deposits in the extraction chain of an irradiated fuel treatment plant. The process chosen allows the detection, in the extraction batteries or in the highly active chemical engineering equipment, of plutonium quantities of a few grams. After four years operation it has been impossible to detect measurable quantities of plutonium in any part of the extraction chain. The results have been confirmed by visual examinations carried out with a specially constructed endoscope. (auth)

PROCESS OF FORMING PLUOTONIUM SALTS FROM PLUTONIUM EXALATES

DOEpatents

Garner, C.S.

1959-02-24

A process is presented for converting plutonium oxalate to other plutonium compounds by a dry conversion method. According to the process, lower valence plutonium oxalate is heated in the presence of a vapor of a volatile non- oxygenated monobasic acid, such as HCl or HF. For example, in order to produce plutonium chloride, the pure plutonium oxalate is heated to about 700 deg C in a slow stream of hydrogen plus HCl. By the proper selection of an oxidizing or reducing atmosphere, the plutonium halide product can be obtained in either the plus 3 or plus 4 valence state.

Comparisons of the skeletal locations of putative plutonium-induced osteosarcomas in humans with those in beagle dogs and with naturally occurring tumors in both species.

PubMed

Miller, Scott C; Lloyd, Ray D; Bruenger, Fred W; Krahenbuhl, Melinda P; Polig, Erich; Romanov, Sergey A

2003-11-01

Osteosarcomas occur from exposures to bone-seeking, alpha-particle-emitting isotopes, particularly plutonium. The skeletal distribution of putative 239Pu-induced osteosarcomas reported in Mayak Metallurgical and Radiochemical Plutonium Plant workers is compared with those observed in canine studies, and these are compared with distributions of naturally occurring osteosarcomas in both species. In the Mayak workers, 29% and 71% of the osteosarcomas were in the peripheral and central skeleton, respectively, with the spine having the most tumors (36%). An almost identical distribution of plutonium-induced osteosarcomas was reported for dogs injected with 239Pu as young adults. This distribution of osteosarcomas is quite different from the distributions of naturally occurring osteosarcomas for both species. In the Cooperative Osteosarcoma Study Group in humans (1,736 osteosarcomas from all ages), over 91% of the tumors occurred in the peripheral skeleton. In the Mayo Clinic group of older individuals (>40 years old), over 60% of the osteosarcomas appeared in the peripheral skeleton. The distribution of naturally occurring osteosarcomas in the canine is similar to that in the adult human. The similarities of the distributions of plutonium-associated osteosarcomas in the Mayak workers with those found in experimental studies suggest that many of the reported osteosarcomas may have been associated with plutonium exposures. These results also support the experimental paradigm that plutonium osteosarcomas have a preference for well vascularized cancellous bone sites. These sites have a greater initial deposition of plutonium, but also greater turnover due to elevated bone remodeling rates.

The production and certification of a plutonium equal-atom reference material: NBL CRM 128

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, D.W.; Gradle, C.G.; Soriano, M.D.

This report describes the design, production, and certification of the New Brunswick Laboratory plutonium equal-atom certified reference material (CRM), NBL CRM 128. The primary use of this CRM is for the determination of bias corrections encountered in the operation of a mass spectrometer. This reference material is available to the US Department of Energy contractor-operated and government-operated laboratories, as well as to the international nuclear safeguards community. The absolute, or unbiased, certified value for the CRM's Pu-242/Pu-239 ratio is 1.00063 {plus minus} 0.00026 (95% confidence interval) as of October 1, 1984. This value was obtained through the quantitative blending ofmore » high-purity, chemically and isotopically characterized separated isotopes, as well as through intercomparisons of CRM samples with calibration mixtures using thermal ionization mass spectrometry. 32 tabs.« less

The iodine-plutonium-xenon age of the Moon-Earth system revisited.

PubMed

Avice, G; Marty, B

2014-09-13

Iodine-plutonium-xenon isotope systematics have been used to re-evaluate time constraints on the early evolution of the Earth-atmosphere system and, by inference, on the Moon-forming event. Two extinct radionuclides ((129)I, T1/2=15.6 Ma and (244)Pu, T1/2=80 Ma) have produced radiogenic (129)Xe and fissiogenic (131-136)Xe, respectively, within the Earth, the related isotope fingerprints of which are seen in the compositions of mantle and atmospheric Xe. Recent studies of Archaean rocks suggest that xenon atoms have been lost from the Earth's atmosphere and isotopically fractionated during long periods of geological time, until at least the end of the Archaean eon. Here, we build a model that takes into account these results. Correction for Xe loss permits the computation of new closure ages for the Earth's atmosphere that are in agreement with those computed for mantle Xe. The corrected Xe formation interval for the Earth-atmosphere system is [Formula: see text] Ma after the beginning of Solar System formation. This time interval may represent a lower limit for the age of the Moon-forming impact. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

DOEpatents

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

1958-10-01

A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This process provides a convenient and efficient means for isolating plutonium.

Geological and Geochemical Characteristics of Skarn Type Lead-Zinc Deposit in Baoshan Block, Yunnan Province

NASA Astrophysics Data System (ADS)

Yao, Xue; Wang, Peng

2017-11-01

Baoshan block is an important Pb-Zn-Fe-Cu polymetallic ore-concentration area which is located in southern of the Sanjiang metallogenic belt in western Yunnan. The article is studying about the geological and geochemical characteristics of the skarn type lead-zinc deposit in Baoshan block. The skarn-type lead-zinc deposit Baoshan block is characterized by skarn and skarn marble, and the orebodies are layered, or bedded along the interlayer fault, which are significantly controlled by structure. The research about Stable isotope S, H and O indicates that the ore-forming fluids are mainly derived from magmatic water, partly mixed with parts of metamorphic water and atmospheric precipitation. The initial Sr isotopic Sr87/Sr86 ratio suggests that the ore-forming materials derived from deep concealed magmatic rock, age of Rb-Sr mineralization is similar to that of Yanshanian granite. In conclusion, the Yanshanian tectonic-magmatic-fluid coupling mineralization of Yanshan formation is the main reason for the skarn-type lead-zinc deposit in the Baoshan block.

PLUTONIUM-CERIUM-COPPER ALLOYS

DOEpatents

Coffinberry, A.S.

1959-05-12

A low melting point plutonium alloy useful as fuel is a homogeneous liquid metal fueled nuclear reactor is described. Vessels of tungsten or tantalum are useful to contain the alloy which consists essentially of from 10 to 30 atomic per cent copper and the balance plutonium and cerium. with the plutontum not in excess of 50 atomic per cent.

Clues in the rare gas isotopes to early solar system history

NASA Technical Reports Server (NTRS)

Reynolds, J. H.

1974-01-01

Rare gases in meteorites and lunar samples are discussed stimulating the discovery of the solar wind. Radioactive isotopes are examined, making a correlation to the origin of the solar system. It is shown that the heights of the peaks above the horizontal lines represent the spectrum of the fissiogenic sample. Nuclear tracks of iodine, xenon, and plutonium detected in lunar rocks are also explained.

Selecting a plutonium vitrification process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jouan, A.

1996-05-01

Vitrification of plutonium is one means of mitigating its potential danger. This option is technically feasible, even if it is not the solution advocated in France. Two situations are possible, depending on whether or not the glass matrix also contains fission products; concentrations of up to 15% should be achievable for plutonium alone, whereas the upper limit is 3% in the presence of fission products. The French continuous vitrification process appears to be particularly suitable for plutonium vitrification: its capacity is compatible with the required throughout, and the compact dimensions of the process equipment prevent a criticality hazard. Preprocessing ofmore » plutonium metal, to convert it to PuO{sub 2} or to a nitric acid solution, may prove advantageous or even necessary depending on whether a dry or wet process is adopted. The process may involve a single step (vitrification of Pu or PuO{sub 2} mixed with glass frit) or may include a prior calcination step - notably if the plutonium is to be incorporated into a fission product glass. It is important to weigh the advantages and drawbacks of all the possible options in terms of feasibility, safety and cost-effectiveness.« less

REMOVAL OF LEGACY PLUTONIUM MATERIALS FROM SWEDEN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunn, Kerry A.; Bellamy, J. Steve; Chandler, Greg T.

2013-08-18

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

SOLVENT EXTRACTION PROCESS FOR PLUTONIUM

DOEpatents

Seaborg, G.T.

1959-04-14

The separation of plutonium from aqueous inorganic acid solutions by the use of a water immiscible organic extractant liquid is described. The plutonium must be in the oxidized state, and the solvents covered by the patent include nitromethane, nitroethane, nitropropane, and nitrobenzene. The use of a salting out agents such as ammonium nitrate in the case of an aqueous nitric acid solution is advantageous. After contacting the aqueous solution with the organic extractant, the resulting extract and raffinate phases are separated. The plutonium may be recovered by any suitable method.

SEPARATION OF PLUTONIUM FROM URANIUM

DOEpatents

Feder, H.M.; Nuttall, R.L.

1959-12-15

A process is described for extracting plutonium from powdered neutron- irradiated urarium metal by contacting the latter, while maintaining it in the solid form, with molten magnesium which takes up the plutonium and separating the molten magnesium from the solid uranium.

SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This processmore » provides a convenient and efficient means for isolating plutonium.« less

SEPARATION OF PLUTONIUM FROM LANTHANUM BY CHELATION-EXTRACTION

DOEpatents

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

1958-12-01

Plutonium can be separated from a mixture of plutonlum and lanthanum in which the lanthanum to plutonium molal ratio ls at least five by adding the ammonium salt of N-nitrosoarylhydroxylamine to an aqueous solution having a pH between about 3 and 0.2 and containing the plutonium in a valence state of at least +3, to form a plutonium chelate compound of N-nitrosoarylhydroxylamine. The plutonium chelate compound may be recovered from the solution by extracting with an immiscible organic solvent such as chloroform.

Ultra-small plutonium oxide nanocrystals: an innovative material in plutonium science.

PubMed

Hudry, Damien; Apostolidis, Christos; Walter, Olaf; Janssen, Arne; Manara, Dario; Griveau, Jean-Christophe; Colineau, Eric; Vitova, Tonya; Prüssmann, Tim; Wang, Di; Kübel, Christian; Meyer, Daniel

2014-08-11

Apart from its technological importance, plutonium (Pu) is also one of the most intriguing elements because of its non-conventional physical properties and fascinating chemistry. Those fundamental aspects are particularly interesting when dealing with the challenging study of plutonium-based nanomaterials. Here we show that ultra-small (3.2±0.9 nm) and highly crystalline plutonium oxide (PuO2 ) nanocrystals (NCs) can be synthesized by the thermal decomposition of plutonyl nitrate ([PuO2 (NO3 )2 ]⋅3 H2 O) in a highly coordinating organic medium. This is the first example reporting on the preparation of significant quantities (several tens of milligrams) of PuO2 NCs, in a controllable and reproducible manner. The structure and magnetic properties of PuO2 NCs have been characterized by a wide variety of techniques (powder X-ray diffraction (PXRD), X-ray absorption fine structure (XAFS), X-ray absorption near edge structure (XANES), TEM, IR, Raman, UV/Vis spectroscopies, and superconducting quantum interference device (SQUID) magnetometry). The current PuO2 NCs constitute an innovative material for the study of challenging problems as diverse as the transport behavior of plutonium in the environment or size and shape effects on the physics of transuranium elements. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tabulated Neutron Emission Rates for Plutonium Oxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shores, Erik Frederick

This work tabulates neutron emission rates for 80 plutonium oxide samples as reported in the literature. Plutonium-­238 and plutonium-­239 oxides are included and such emission rates are useful for scaling tallies from Monte Carlo simulations and estimating dose rates for health physics applications.

PLUTONIUM-URANIUM-TITANIUM ALLOYS

DOEpatents

Coffinberry, A.S.

1959-07-28

A plutonium-uranium alloy suitable for use as the fuel element in a fast breeder reactor is described. The alloy contains from 15 to 60 at.% titanium with the remainder uranium and plutonium in a specific ratio, thereby limiting the undesirable zeta phase and rendering the alloy relatively resistant to corrosion and giving it the essential characteristic of good mechanical workability.

WET METHOD OF PREPARING PLUTONIUM TRIBROMIDE

DOEpatents

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

1958-11-11

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

A METHOD TO IMPROVE DOSE ASSESSMENT BY RECONSTRUCTION OF THE COMPLETE ISOTOPES INVENTORY.

PubMed

Bonin, Alice; Tsilanizara, Aimé

2017-06-01

Radiation shielding assessments may underestimate the expected dose if some isotopes at trace level are not considered in the isotopes inventory of the shielded radioactive materials. Indeed, information about traces is not often available. Nevertheless, the activation of some minor isotopic traces may significantly contribute to the dose build-up. This paper presents a new method (Isotopes Inventory Reconstruction-IIR) estimating the concentration of the minor isotopes in the irradiated material at the beginning of the cooling period. The method requires the solution of the inverse problem describing the irradiated material's decay. In a mixture of an irradiated uranium-plutonium oxide shielded by a set-up made of stainless-steel, porous polyethylene plaster and lead methyl methacrylate, the comparison between different methods proves that the IIR-method allows better assessment of the dose than other approximate methods. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

IMPROVED PROCESS OF PLUTONIUM CARRIER PRECIPITATION

DOEpatents

Faris, B.F.

1959-06-30

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

OXIDATIVE METHOD OF SEPARATING PLUTONIUM FROM NEPTUNIUM

DOEpatents

Beaufait, L.J. Jr.

1958-06-10

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

PLUTONIUM ALLOYS CONTAINING CONTROLLED AMOUNTS OF PLUTONIUM ALLOTROPES OBTAINED BY APPLICATION OF HIGH PRESSURES

DOEpatents

Elliott, R.O.; Gschneidner, K.A. Jr.

1962-07-10

A method of making stabilized plutonium alloys which are free of voids and cracks and have a controlled amount of plutonium allotropes is described. The steps include adding at least 4.5 at.% of hafnium, indium, or erbium to the melted plutonium metal, homogenizing the resulting alloy at a temperature of 450 deg C, cooling to room temperature, and subjecting the alloy to a pressure which produces a rapid increase in density with a negligible increase in pressure. The pressure required to cause this rapid change in density or transformation ranges from about 800 to 2400 atmospheres, and is dependent on the alloying element. (AEC)

METHOD OF REDUCING PLUTONIUM COMPOUNDS

DOEpatents

Johns, I.B.

1958-06-01

A method is described for reducing plutonium compounds in aqueous solution from a higher to a lower valence state. This reduction of valence is achieved by treating the aqueous solution of higher valence plutonium compounds with hydrogen in contact with an activated platinum catalyst.

PLUTONIUM RECOVERY FROM NEUTRON-BOMBARDED URANIUM FUEL

DOEpatents

Moore, R.H.

1962-04-10

A process of recovering plutonium from neutronbombarded uranium fuel by dissolving the fuel in equimolar aluminum chloride-potassium chloride; heating the mass to above 700 deg C for decomposition of plutonium tetrachloride to the trichloride; extracting the plutonium trichloride into a molten salt containing from 40 to 60 mole % of lithium chloride, from 15 to 40 mole % of sodium chloride, and from 0 to 40 mole % of potassium chloride or calcium chloride; and separating the layer of equimolar chlorides containing the uranium from the layer formed of the plutonium-containing salt is described. (AEC)

Plutonium age dating reloaded

NASA Astrophysics Data System (ADS)

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

2014-05-01

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.

Zn and C isotopic evidence of climatic change during the Marinoan

NASA Astrophysics Data System (ADS)

Thiemens, M. M.; Moynier, F.; Koeberl, C.; Thiemens, M. H.; Shaheen, R.; Gyollai, I.; Popp, F.; Chong, K.

2011-12-01

The "Snowball Earth" events of the Cryogenian period are renowned for their remarkable chemical and isotopic signatures left in the geological record. Through analysis of post Marinoan glaciation cap carbonates from Namibia, specifically from Fransfontein, the Khowarib Valley, and Naraachamspos, a multi isotopic study was undertaken. We analyzed the δ 13C of chemically isolated calcite and dolomite. A moderate depletion of 13C in calcite (δ 13C<0% V-PDB) associated with global glaciations was observed, confirming the event. Associated dolomites also show a 13C depletion, but at a much lower magnitude. Zinc is a trace element that is necessary for all forms of life. Zn does not undergo redox cycling under normal environmental conditions, and biological uptake is one of the few processes that produces isotopic fractionation. This fractionation is in the range of 0.1 permil for the 66Zn/64Zn ratio (δ 66Zn in permil deviation), however with the advent of multi-collection inductively-coupled plasma mass spectrometry (MC-ICP-MS) such variations have become resolvable. We also have measured the Zinc composition of multiple species of lab cultured archaea, and found that the cells are enriched in the light isotopes of Zn compared to the culture medium. By measuring Zn levels in the Cap Carbonates, we seek corroboration for the carbon depletion we find during the glaciation. Zinc should undergo a similarly significant alteration at the mass extinction from climatic shifts inherent to a worldwide glaciation. We find the samples to be relatively consistent, with a δ 66Zn of approximately 0.30 to 0.40 in most places, with a δ 68Zn of double that, values typical of terrestrial rocks. Several sites have a much larger fractionation, with δ 66Zn of up to 0.90 in the Khowarib Valley, and up to 1.06 in the clays at the entrance to the South Valley. These isotopic compositions may be indicative of the massive climatic event leading to the formation of the cap carbonates.

Volatile fluoride process for separating plutonium from other materials

DOEpatents

Spedding, F. H.; Newton, A. S.

1959-04-14

The separation of plutonium from uranium and/or fission products by formation of the higher fluorides off uranium and/or plutonium is described. Neutronirradiated uranium metal is first converted to the hydride. This hydrided product is then treated with fluorine at about 315 deg C to form and volatilize UF/sub 6/ leaving plutonium behind. Thc plutonium may then be separated by reacting the residue with fluorine at about 5004DEC and collecting the volatile plutonium fluoride thus formed.

Determination of 240Pu/239Pu isotopic ratios in human tissues collected from areas around the Semipalatinsk Nuclear Test Site by sector-field high resolution ICP-MS.

PubMed

Yamamoto, M; Oikawa, S; Sakaguchi, A; Tomita, J; Hoshi, M; Apsalikov, K N

2008-09-01

Information on the 240Pu/239Pu isotope ratios in human tissues for people living around the Semipalatinsk Nuclear Test Site (SNTS) was deduced from 9 sets of soft tissues and bones, and 23 other bone samples obtained by autopsy. Plutonium was radiochemically separated and purified, and plutonium isotopes (239Pu and 240Pu) were determined by sector-field high resolution inductively coupled plasma-mass spectrometry. For most of the tissue samples from the former nine subjects, low 240Pu/239Pu isotope ratios were determined: bone, 0.125 +/- 0.018 (0.113-0.145, n = 4); lungs, 0.063 +/- 0.010 (0.051-0.078, n = 5); and liver, 0.148 +/- 0.026 (0.104-0.189, n = 9). Only 239Pu was detected in the kidney samples; the amount of 240Pu was too small to be measured, probably due to the small size of samples analyzed. The mean 240Pu/239Pu isotope ratio for bone samples from the latter 23 subjects was 0.152 +/- 0.034, ranging from 0.088 to 0.207. A significant difference (a two-tailed Student's t test; 95% significant level, alpha = 0.05) between mean 240Pu/239Pu isotope ratios for the tissue samples and for the global fallout value (0.178 +/- 0.014) indicated that weapons-grade plutonium from the atomic bombs has been incorporated into the human tissues, especially lungs, in the residents living around the SNTS. The present 239,240Pu concentrations in bone, lung, and liver samples were, however, not much different from ranges found for human tissues from other countries that were due solely to global fallout during the 1970's-1980's.

Plutonium and americium separation from salts

DOEpatents

Hagan, Paul G.; Miner, Frend J.

1976-01-01

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

VOLATILE FLUORIDE PROCESS FOR SEPARATING PLUTONIUM FROM OTHER MATERIALS

DOEpatents

Spedding, F.H.; Newton, A.S.

1959-04-14

The separation of plutonium from uranium and/or tission products by formation of the higher fluorides of uranium and/or plutonium is discussed. Neutronirradiated uranium metal is first convcrted to the hydride. This hydrided product is then treatced with fluorine at about 315 deg C to form and volatilize UF/sup 6/ leaving plutonium behind. The plutonium may then be separated by reacting the residue with fluorine at about 500 deg C and collecting the volatile plutonium fluoride thus formed.

Separation of copper, iron, and zinc from complex aqueous solutions for isotopic measurement

USGS Publications Warehouse

Borrok, D.M.; Wanty, R.B.; Ridley, W.I.; Wolf, R.; Lamothe, P.J.; Adams, M.

2007-01-01

The measurement of Cu, Fe, and Zn isotopes in natural samples may provide valuable information about biogeochemical processes in the environment. However, the widespread application of stable Cu, Fe, and Zn isotope chemistry to natural water systems remains limited by our ability to efficiently separate these trace elements from the greater concentrations of matrix elements. In this study, we present a new method for the isolation of Cu, Fe, and Zn from complex aqueous solutions using a single anion-exchange column with hydrochloric acid media. Using this method we are able to quantitatively separate Cu, Fe, and Zn from each other and from matrix elements in a single column elution. Elution of the elements of interest, as well as all other elements, through the anion-exchange column is a function of the speciation of each element in the various concentrations of HCl. We highlight the column chemistry by comparing our observations with published studies that have investigated the speciation of Cu, Fe, and Zn in chloride solutions. The functionality of the column procedure was tested by measuring Cu, Fe, and Zn isotopes in a variety of stream water samples impacted by acid mine drainage. The accuracy and precision of Zn isotopic measurements was tested by doping Zn-free stream water with the Zn isotopic standard. The reproducibility of the entire column separation process and the overall precision of the isotopic measurements were also evaluated. The isotopic results demonstrate that the Cu, Fe, and Zn column separates from the tested stream waters are of sufficient purity to be analyzed directly using a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS), and that the measurements are fully-reproducible, accurate, and precise. Although limited in scope, these isotopic measurements reveal significant variations in ??65Cu (- 1.41 to + 0.30???), ??56Fe (- 0.56 to + 0.34???), and ??66Zn (0.31 to 0.49???) among samples collected from different

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jardine, L J; Borisov, G B

2004-07-21

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

Decorporation Approach after Rat Lung Contamination with Plutonium: Evaluation of the Key Parameters Influencing the Efficacy of a Protracted Chelation Treatment.

PubMed

Grémy, Olivier; Coudert, Sylvie; Renault, Daniel; Miccoli, Laurent

2017-11-01

While the efficacy of a protracted zinc (Zn)- or calcium (Ca)-diethylenetriaminepentaacetic acid (DTPA) treatment in reducing transuranic body burden has already been demonstrated, questions about therapeutic variables remain. In response to this, we designed animal experiments primarily to assess both the effect of fractionation of a given dose and the effect of the frequency of dose fraction, with the same total dose. In our study, rats were contaminated intravenously with plutonium (Pu) then treated several days later with Ca-DTPA given at once or in various split-dose regimens cumulating to the same total dose and spread over several days. Similar efficacies were induced by the injection of the total dose or by splitting the dose in several smaller doses, independent of the number of doses and the dose level per injection. In a second study, rats were pulmonary contaminated, and three weeks later they received a Ca-DTPA dose 11-fold higher than the maximal daily recommended dose, administered either as a single bolus or as numerous multiple injections cumulating to the same dose, based on different injection frequency schedules. Independent of frequency schedule, the various split-dose regimens spread over weeks/months were as efficient as single delivery of the total dose in mobilizing lung plutonium, and had a therapeutic advantage for removal of retained hepatic and bone plutonium burdens. We concluded that cumulative dose level was a therapeutic variable of greater importance than the distribution of split doses for the success of a repeated treatment regimen on retained tissue plutonium. In addition, pulmonary administration of clodronate, which aims at killing alveolar macrophages and subsequently releasing their plutonium content, and which is associated with a continuous Ca-DTPA infusion regimen, suggested that the efficacy of injected Ca-DTPA in decorporating lung deposit is limited, due to its restricted penetration into alveolar macrophages and not

Zinc isotope fractionation during adsorption onto Mn oxyhydroxide at low and high ionic strength

NASA Astrophysics Data System (ADS)

Bryan, Allison L.; Dong, Shuofei; Wilkes, Elise B.; Wasylenki, Laura E.

2015-05-01

Marine ferromanganese sediments represent one of the largest sinks from global seawater for Zn, a critical trace metal nutrient. These sediments are variably enriched in heavier isotopes of Zn relative to deep seawater, and some are among the heaviest natural samples analyzed to date. New experimental results demonstrate that adsorption of Zn to poorly crystalline Mn oxyhydroxide results in preferential association of heavier isotopes with the sorbent phase. At low ionic strength our experimental system displayed a short-lived kinetic isotope effect, with light isotopes adsorbed to birnessite (Δ66/64Znadsorbed-dissolved ∼ -0.2‰). After 100 h the sense of fractionation was opposite, such that heavier isotopes were preferentially adsorbed at steady state, but the magnitude of Δ66/64Znadsorbed-dissolved was indistinguishable from zero (+0.05 ± 0.08‰). At high ionic strength, we observed preferential sorption of heavy isotopes, with a strong negative correlation between Δ66/64Znadsorbed-dissolved and the percentage of Zn on the birnessite. Values of Δ66/64Znadsorbed-dissolved ranged from nearly +3‰ at low surface loading to +0.16‰ at high surface loading. Based on previous EXAFS work we infer that Zn adsorbs first as tetrahedral, inner-sphere complexes at low surface loading, with preferential incorporation of heavier isotopes relative to the octahedral Zn species predominating in solution. As surface loading increases, so does the proportion of Zn adsorbing as octahedral complexes, thus diminishing the magnitude of fractionation between the dissolved and adsorbed pools of Zn. The magnitude of fractionation at high ionic strength is also governed by aqueous speciation of Zn in synthetic seawater; a substantial fraction of Zn ions reside in chloro complexes, which preferentially incorporate light Zn isotopes, and this drives the adsorbed pool to be heavier relative to the bulk solution than it was at low ionic strength. Our results explain the observation

PREPARATION OF HALIDES OF PLUTONIUM

DOEpatents

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

1958-09-01

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

Removal of plutonium from hepatic tissue

DOEpatents

Lindenbaum, Arthur; Rosenthal, Marcia W.

1979-01-01

A method is provided for removing plutonium from hepatic tissues by introducing into the body and blood stream a solution of the complexing agent DTPA and an adjunct thereto. The adjunct material induces aberrations in the hepatic tissue cells and removes intracellularly deposited plutonium which is normally unavailable for complexation with the DTPA. Once the intracellularly deposited plutonium has been removed from the cell by action of the adjunct material, it can be complexed with the DTPA present in the blood stream and subsequently removed from the body by normal excretory processes.

The calculation of annual limits of intake for plutonium-239 in man using a bone model which allows for plutonium burial and recycling.

PubMed

Priest, N D; Hunt, B W

1979-05-01

Values of the annual limit of intake (ALI) for plutonium-239 in man have been calculated using committed dose equivalent limits as recommended by ICRP in Publication 26. The calculations were made using a multicompartment bone model which allows for plutonium burial and recycling in the skeleton. In one skeletal compartment, the growing surfaces of cortical bone, it is assumed that plutonium deposits are retained and are not subject to resorption or recycling. In the trabecular bone compartment plutonium is taken to be resorbed with either subsequent redeposition onto bone surfaces or retention in the bone marrow. ALIs for plutonium-239 have been calculated assuming a range of rates of bone accretion (0-32 micron yr-1), different amounts of plutonium retained in the marrow (0-60%) and a 20%, 45% or 70% deposition of plutonium in the skeleton from the blood. The calculations made using this bone model suggest that 750 Bq (20 nCi) is an appropriate ALI for the inhalation of class W and class Y plutonium compounds and that 830 kBq and 5 MBq (23 muCi and 136 muCi) are the appropriate ALIs for the ingestion of soluble and insoluble forms of plutonium respectively.

Zinc electrode and rechargeable zinc-air battery

DOEpatents

Ross, Jr., Philip N.

1989-01-01

An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

Spectrophotometers for plutonium monitoring in HB-line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lascola, R. J.; O'Rourke, P. E.; Kyser, E. A.

2016-02-12

This report describes the equipment, control software, calibrations for total plutonium and plutonium oxidation state, and qualification studies for the instrument. It also provides a detailed description of the uncertainty analysis, which includes source terms associated with plutonium calibration standards, instrument drift, and inter-instrument variability. Also included are work instructions for instrument, flow cell, and optical fiber setup, work instructions for routine maintenance, and drawings and schematic diagrams.

SEPARATION OF URANIUM, PLUTONIUM, AND FISSION PRODUCTS

DOEpatents

Spence, R.; Lister, M.W.

1958-12-16

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

ION EXCHANGE ADSORPTION PROCESS FOR PLUTONIUM SEPARATION

DOEpatents

Boyd, G.E.; Russell, E.R.; Taylor, M.D.

1961-07-11

Ion exchange processes for the separation of plutonium from fission products are described. In accordance with these processes an aqueous solution containing plutonium and fission products is contacted with a cation exchange resin under conditions favoring adsorption of plutonium and fission products on the resin. A portion of the fission product is then eluted with a solution containing 0.05 to 1% by weight of a carboxylic acid. Plutonium is next eluted with a solution containing 2 to 8 per cent by weight of the same carboxylic acid, and the remaining fission products on the resin are eluted with an aqueous solution containing over 10 per cent by weight of sodium bisulfate.

Radiation damage and annealing in plutonium tetrafluoride

NASA Astrophysics Data System (ADS)

McCoy, Kaylyn; Casella, Amanda; Sinkov, Sergey; Sweet, Lucas; McNamara, Bruce; Delegard, Calvin; Jevremovic, Tatjana

2017-12-01

A sample of plutonium tetrafluoride that was separated prior to 1966 at the Hanford Site in Washington State was analyzed at the Pacific Northwest National Laboratory (PNNL) in 2015 and 2016. The plutonium tetrafluoride, as received, was an unusual color and considering the age of the plutonium, there were questions about the condition of the material. These questions had to be answered in order to determine the suitability of the material for future use or long-term storage. Therefore, thermogravimetric/differential thermal analysis and X-ray diffraction evaluations were conducted to determine the plutonium's crystal structure, oxide content, and moisture content; these analyses reported that the plutonium was predominately amorphous and tetrafluoride, with an oxide content near ten percent. Freshly fluorinated plutonium tetrafluoride is known to be monoclinic. During the initial thermogravimetric/differential thermal analyses, it was discovered that an exothermic event occurred within the material near 414 °C. X-ray diffraction analyses were conducted on the annealed tetrafluoride. The X-ray diffraction analyses indicated that some degree of recrystallization occurred in conjunction with the 414 °C event. The following commentary describes the series of thermogravimetric/differential thermal and X-ray diffraction analyses that were conducted as part of this investigation at PNNL.

Radiation damage and annealing in plutonium tetrafluoride

DOE PAGES

McCoy, Kaylyn; Casella, Amanda; Sinkov, Sergey; ...

2017-08-03

A sample of plutonium tetrafluoride that was separated prior to 1966 at the Hanford Site in Washington State was analyzed at the Pacific Northwest National Laboratory (PNNL) in 2015 and 2016. The plutonium tetrafluoride, as received, was an unusual color and considering the age of the plutonium, there were questions about the condition of the material. These questions had to be answered in order to determine the suitability of the material for future use or long-term storage. Therefore, thermogravimetric/differential thermal analysis and X-ray diffraction evaluations were conducted to determine the plutonium's crystal structure, oxide content, and moisture content; these analysesmore » reported that the plutonium was predominately amorphous and tetrafluoride, with an oxide content near ten percent. Freshly fluorinated plutonium tetrafluoride is known to be monoclinic. And during the initial thermogravimetric/differential thermal analyses, it was discovered that an exothermic event occurred within the material near 414 °C. X-ray diffraction analyses were conducted on the annealed tetrafluoride. The X-ray diffraction analyses indicated that some degree of recrystallization occurred in conjunction with the 414 °C event. This commentary describes the series of thermogravimetric/differential thermal and X-ray diffraction analyses that were conducted as part of this investigation at PNNL.« less

EXAFS/XANES studies of plutonium-loaded sodalite/glass waste forms

NASA Astrophysics Data System (ADS)

Richmann, Michael K.; Reed, Donald T.; Kropf, A. Jeremy; Aase, Scott B.; Lewis, Michele A.

2001-09-01

A sodalite/glass ceramic waste form is being developed to immobilize highly radioactive nuclear wastes in chloride form, as part of an electrochemical cleanup process. Two types of simulated waste forms were studied: where the plutonium was alone in an LiCl/KCl matrix and where simulated fission-product elements were added representative of the electrometallurgical treatment process used to recover uranium from spent nuclear fuel also containing plutonium and a variety of fission products. Extended X-ray absorption fine structure spectroscopy (EXAFS) and X-ray absorption near-edge spectroscopy (XANES) studies were performed to determine the location, oxidation state, and particle size of the plutonium within these waste form samples. Plutonium was found to segregate as plutonium(IV) oxide with a crystallite size of at least 4.8 nm in the non-fission-element case and 1.3 nm with fission elements present. No plutonium was observed within the sodalite in the waste form made from the plutonium-loaded LiCl/KCl eutectic salt. Up to 35% of the plutonium in the waste form made from the plutonium-loaded simulated fission-product salt may be segregated with a heavy-element nearest neighbor other than plutonium or occluded internally within the sodalite lattice.

PROCESS OF SEPARATING PLUTONIUM VALUES BY ELECTRODEPOSITION

DOEpatents

Whal, A.C.

1958-04-15

A process is described of separating plutonium values from an aqueous solution by electrodeposition. The process consists of subjecting an aqueous 0.1 to 1.0 N nitric acid solution containing plutonium ions to electrolysis between inert metallic electrodes. A current density of one milliampere io one ampere per square centimeter of cathode surface and a temperature between 10 and 60 d C are maintained. Plutonium is electrodeposited on the cathode surface and recovered.

Safe disposal of surplus plutonium

NASA Astrophysics Data System (ADS)

Gong, W. L.; Naz, S.; Lutze, W.; Busch, R.; Prinja, A.; Stoll, W.

2001-06-01

About 150 tons of weapons grade and weapons usable plutonium (metal, oxide, and in residues) have been declared surplus in the USA and Russia. Both countries plan to convert the metal and oxide into mixed oxide fuel for nuclear power reactors. Russia has not yet decided what to do with the residues. The US will convert residues into a ceramic, which will then be over-poured with highly radioactive borosilicate glass. The radioactive glass is meant to provide a deterrent to recovery of plutonium, as required by a US standard. Here we show a waste form for plutonium residues, zirconia/boron carbide (ZrO 2/B 4C), with an unprecedented combination of properties: a single, radiation-resistant, and chemically durable phase contains the residues; billion-year-old natural analogs are available; and criticality safety is given under all conceivable disposal conditions. ZrO 2/B 4C can be disposed of directly, without further processing, making it attractive to all countries facing the task of plutonium disposal. The US standard for protection against recovery can be met by disposal of the waste form together with used reactor fuel.

Isotope geochemistry of waters affected by acid mine drainage in old labour sites (SE, Spain).

NASA Astrophysics Data System (ADS)

Pérez-Sirvent, Carmen; Martinez-Sanchez, Maria Jose; Garcia-Lorenzo, Maria Luz; Agudo, Ines; Hernandez-Cordoba, Manuel; Recio, Clemente

2015-04-01

The ore deposits of this zone have iron, lead and zinc as the main metal components. Iron is present in oxides, hydroxides, sulfides, sulfates, carbonates, and silicates; lead and zinc occur in sulfides (galena and sphalerite, respectively), carbonates, sulfates, and lead or zinc-bearing (manganese, iron) oxides. Mining started with the Romans and activity peaked in the second half of the 19th century and throughout the 20th century until the 1980's. From 1940 to 1957, mineral concentration was made by froth flotation and, prior to this, by gravimetric techniques. The mining wastes, or tailings, with a very fine particle size were deposited inland (tailings dams) and, since 1957, huge releases were made in directly the sea coast. The objective of this work was to evaluate processes affecting waters from abandoned mine sites by way of stable isotopic analysis, particularly H and O stable isotopes from water and S and O from dissolved sulfates. Several common chemical and physical processes, such as evaporation, water-rock interaction and mixing could alter water isotopic composition. Evaporation, which causes an enrichment in δD and δ18O in the residual water, is an important process in semiarid areas. The results obtained indicate that, for sites near the coast, waters are meteoric, and marine infiltration only takes place in the deepest layers near the shore or if water remains stagnated in sediments with low permeability. The main source of sulfate was the oxidation of sulfides, resulting in the liberation of acid, sulfate and metals. In order to assess the mechanism responsible for sulfide oxidation, the stoichiometric isotope balance model and the general isotope balance model were tested, suggesting that the oxidation via Fe3+ was predominant in the surface, and controlled by A. ferrooxidans, while at depth, sulfate reduction occurred.

Photoemission Spectroscopy of Delta- Plutonium: Experimental Review

NASA Astrophysics Data System (ADS)

Tobin, J. G.

2002-03-01

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

Zinc in an ultraoligotrophic lake food web.

PubMed

Montañez, Juan Cruz; Arribére, María A; Rizzo, Andrea; Arcagni, Marina; Campbell, Linda; Ribeiro Guevara, Sergio

2018-06-01

Zinc (Zn) bioaccumulation and trophic transfer were analyzed in the food web of Lake Nahuel Huapi, a deep, unpolluted ultraoligotrophic system in North Patagonia. Benthic macroinvertebrates, plankton, and native and introduced fish were collected at three sites. The effect of pyroclastic inputs on Zn levels in lacustrine food webs was assessed by studying the impact of the eruption of Puyehue-Cordón Caulle volcanic complex (PCCVC) in 2011, by performing three sampling campaigns immediately before and after the PCCVC eruption, and after 2 years of recovery of the ecosystem. Zinc trophodynamics in L. Nahuel Huapi food web was assessed using nitrogen stable isotopes (δ 15 N). There was no significant increase of Zn concentrations ([Zn]) in L. Nahuel Huapi biota after the PCCVC eruption, despite the evidence of [Zn] increase in lake water that could be associated with volcanic ash leaching. The organisms studied exhibited [Zn] above the threshold level considered for dietary deficiency, regulating Zn adequately even under a catastrophic situations like PCCVC 2011 eruption. Zinc concentrations exhibited a biodilution pattern in the lake's food web. To the best of our knowledge, present research is the first report of Zn biodilution in lacustrine systems, and the first to study Zn transfer in a freshwater food web including both pelagic and benthic compartments.

Spatial evolution of Zn-Fe-Pb isotopes of sphalerite within a single ore body: A case study from the Dongshengmiao ore deposit, Inner Mongolia, China

NASA Astrophysics Data System (ADS)

Gao, Zhaofu; Zhu, Xiangkun; Sun, Jian; Luo, Zhaohua; Bao, Chuang; Tang, Chao; Ma, Jianxiong

2018-01-01

Analyses of sphalerite minerals from the characteristic brecciated Zn-Pb ores of the main ore body in the giant Dongshengmiao deposit have revealed variations in δ66Zn from 0.17 to 0.40‰ and in δ56Fe from -1.78 to -0.35‰. Further, the investigated pyrrhotite samples have iron that is isotopically similar to that of associated sphalerite minerals. The most distinctive pattern revealed by the zinc and iron isotope data is the lateral trend of increasing δ66Zn and δ56Fe values from southwest to northeast within the main ore body. The lead isotopic homogeneity of ore sulfides from the main ore body suggests that there is only one significant source for metal, thus precluding the mixing of multiple metal sources as the key factor controlling spatial variations of zinc and iron isotopes. The most likely control on spatial variations is Rayleigh fractionation during hydrothermal fluid flow, with lighter Zn and Fe isotopes preferentially incorporated into the earliest sulfides to precipitate from fluids. Precipitations of sphalerite and pyrrhotite have played vital roles in the Zn and Fe isotopic variations, respectively, of the ore-forming system. Accordingly, the larger isotopic variability for Fe than Zn within the same hydrothermal system perhaps resulted from a larger proportion of precipitation for pyrrhotite than for sphalerite. The lateral trend pattern revealed by the zinc and iron isotope data is consistent with the occurrence of a cystic-shaped breccia zone, which is characterized by marked elevation in Cu. The results further confirm that Zn and Fe isotopes can be used as a vectoring tool for mineral prospecting.

Solvent extraction system for plutonium colloids and other oxide nano-particles

DOEpatents

Soderholm, Lynda; Wilson, Richard E; Chiarizia, Renato; Skanthakumar, Suntharalingam

2014-06-03

The invention provides a method for extracting plutonium from spent nuclear fuel, the method comprising supplying plutonium in a first aqueous phase; contacting the plutonium aqueous phase with a mixture of a dielectric and a moiety having a first acidity so as to allow the plutonium to substantially extract into the mixture; and contacting the extracted plutonium with second a aqueous phase, wherein the second aqueous phase has a second acidity higher than the first acidity, so as to allow the extracted plutonium to extract into the second aqueous phase. The invented method facilitates isolation of plutonium polymer without the formation of crud or unwanted emulsions.

Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage.

PubMed

Hemilä, Harri

2017-05-01

To compare the efficacy of zinc acetate lozenges with zinc gluconate lozenges in common cold treatment and to examine the dose-dependency of the effect. Meta-analysis. Placebo-controlled zinc lozenge trials, in which the zinc dose was > 75 mg/day. The pooled effect of zinc lozenges on common cold duration was calculated by using inverse-variance random-effects method. Seven randomised trials with 575 participants with naturally acquired common colds. Duration of the common cold. The mean common cold duration was 33% (95% CI 21% to 45%) shorter for the zinc groups of the seven included trials. Three trials that used lozenges composed of zinc acetate found that colds were shortened by 40% and four trials that used zinc gluconate by 28%. The difference between the two salts was not significant: 12 percentage points (95% CI: -12 to + 36). Five trials used zinc doses of 80-92 mg/day, common cold duration was reduced by 33%, and two trials used zinc doses of 192-207 mg/day and found an effect of 35%. The difference between the high-dose and low-dose zinc trials was not significant: 2 percentage points (95% CI: -29 to + 32). Properly composed zinc gluconate lozenges may be as effective as zinc acetate lozenges. There is no evidence that zinc doses over 100 mg/day might lead to greater efficacy in the treatment of the common cold. Common cold patients may be encouraged to try zinc lozenges for treating their colds. The optimal lozenge composition and dosage scheme need to be investigated further.

Lymph node clearance of plutonium from subcutaneous wounds in beagles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dagle, G.E.

1973-08-01

The lymph node clearance of /sup 239/Pu O/sub 2/ administered as insoluble particles from subcutaneous implants was studied in adult beagles to simulate accidental contamination of hand wounds. External scintillation data were collected from the popliteal lymph nodes of each dog after 9.2 to 39.4 mu Ci of plutonium oxide was subcutaneously implanted into the left or right hind paws. The left hind paw was armputated 4 weeks after implantation to prevent continued deposition of plutonium oxide particles in the left popliteal lymph node. Groups of 3 dogs were sacrificed 4, 8, 16, and 32 weeks after plutonium implantation formore » histopathologic, electron microscopic, and radiochemical analysis of regional lymph nodes. An additional group of dogs received treatment with the chelating agent diethyenetriaminepentaacetic acid (DTPA). Plutonium rapidly accumulated in the popliteal lymph nodes after subcutaneous injection into the hind paw, and 1 to 10% of the implant dose was present in the popliteal lymph nodes at the time of necropsy. Histopathologic changes in the popliteal lymph nodes with plutonium particles were characterized primarily by reticular cell hyperplasia, increased numbers of macrophages, necrosis, and fibroplasia. Eventually, the plutonium particles became sequestered by scar tissue that often replaced the entire architecture of the lymph node. Light microscopic autoradiographs of the popliteal lymph nodes showed a time-related increase in number of alpha tracks per plutonium source. Electron microscopy showed that the plutonium particles were aggregated in phagolysosomes of macrophages. There was slight clearance of plutonium from the popliteal lymph nodes of dogs monitored for 32 weeks. The clearance of plutonium particles from the popliteal lymph nodes was associated with necrosis of macrophages. The external iliac lymph nodes contained fewer plutonium particles than the popliteal lymph nodes and histopathologic changes were less severe. The

Dietary phytate, zinc and hidden zinc deficiency.

PubMed

Sandstead, Harold H; Freeland-Graves, Jeanne H

2014-10-01

Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

RECOVERY OF PLUTONIUM BY CARRIER PRECIPITATION

DOEpatents

Goeckermann, R.H.

1961-04-01

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

PROCESS FOR PRODUCTION OF PLUTONIUM FROM ITS OXIDES

DOEpatents

Weissman, S.I.; Perlman, M.L.; Lipkin, D.

1959-10-13

A method is described for obtaining a carbide of plutonium and two methods for obtaining plutonium metal from its oxides. One of the latter involves heating the oxide, in particular PuO/sub 2/, to a temperature of 1200 to 1500 deg C with the stoichiometrical amount of carbon to fornn CO in a hard vacuum (3 to 10 microns Hg), the reduced and vaporized plutonium being collected on a condensing surface above the reaction crucible. When an excess of carbon is used with the PuO/sub 2/, a carbide of plutonium is formed at a crucible temperature of 1400 to 1500 deg C. The process may be halted and the carbide removed, or the reaction temperature can be increased to 1900 to 2100 deg C at the same low pressure to dissociate the carbide, in which case the plutonium is distilled out and collected on the same condensing surface.

Acute changes in cellular zinc alters zinc uptake rates prior to zinc transporter gene expression in Jurkat cells.

PubMed

Holland, Tai C; Killilea, David W; Shenvi, Swapna V; King, Janet C

2015-12-01

A coordinated network of zinc transporters and binding proteins tightly regulate cellular zinc levels. Canonical responses to zinc availability are thought to be mediated by changes in gene expression of key zinc transporters. We investigated the temporal relationships of actual zinc uptake with patterns of gene expression in membrane-bound zinc transporters in the human immortalized T lymphocyte Jurkat cell line. Cellular zinc levels were elevated or reduced with exogenous zinc sulfate or N,N,N',N-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), respectively. Excess zinc resulted in a rapid 44 % decrease in the rate of zinc uptake within 10 min. After 120 min, the expression of metallothionein (positive control) increased, as well as the zinc exporter, ZnT1; however, the expression of zinc importers did not change during this time period. Zinc chelation with TPEN resulted in a rapid twofold increase in the rate of zinc uptake within 10 min. After 120 min, the expression of ZnT1 decreased, while again the expression of zinc importers did not change. Overall, zinc transporter gene expression kinetics did not match actual changes in cellular zinc uptake with exogenous zinc or TPEN treatments. This suggests zinc transporter regulation may be the initial response to changes in zinc within Jurkat cells.

Plutonium recovery from spent reactor fuel by uranium displacement

DOEpatents

Ackerman, J.P.

1992-03-17

A process is described for separating uranium values and transuranic values from fission products containing rare earth values when the values are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is reestablished.

Plutonium recovery from spent reactor fuel by uranium displacement

DOEpatents

Ackerman, John P.

1992-01-01

A process for separating uranium values and transuranic values from fission products containing rare earth values when the values are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is reestablished.

MOLTEN PLUTONIUM FUELED FAST BREEDER REACTOR

DOEpatents

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

1962-06-26

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

Zinc Enzymes.

ERIC Educational Resources Information Center

Bertini, I.; And Others

1985-01-01

Discusses the role of zinc in various enzymes concerned with hydration, hydrolysis, and redox reactions. The binding of zinc to protein residues, properties of noncatalytic zinc(II) and catalytic zinc, and the reactions catalyzed by zinc are among the topics considered. (JN)

Neutron Radiation Characteristics of Plutonium Dioxide Fuel

NASA Technical Reports Server (NTRS)

Taherzadeh, M.

1972-01-01

The major sources of neutrons from plutonium dioxide nuclear fuel are considered in detail. These sources include spontaneous fission of several of the Pu isotopes, reactions with low Z impurities in the fuel, and reactions with O-18. For spontaneous fission neutrons a value of (1.95 plus or minus 0.07) X 1,000 n/s/q PuO2 is obtained. The neutron yield from (alpha, neutron) reactions with oxygen is calculated by integrating the reaction rate equation over all alpha particle energies and all center-of-mass angles. The results indicate a neutron emission rate of (1.42 plus or minus 0.32) X 10,000 n/s/q PuO2. The neutron yield from (alpha, neutron) reactions with low Z impurities in the fuel is presented in tabular form for one part per million of each impurity. The total neutron flux emitted from a particular fuel geometry is estimated by adding the neutron yield due to the induced fission to the other neutron sources.

METHOD OF PREPARING PLUTONIUM TETRAFLUORIDE

DOEpatents

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

1959-11-17

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

Pyrochemical recovery of plutonium from calcium fluoride reduction slag

DOEpatents

Christensen, D.C.

A pyrochemical method of recovering finely dispersed plutonium metal from calcium fluoride reduction slag is claimed. The plutonium-bearing slag is crushed and melted in the presence of at least an equimolar amount of calcium chloride and a few percent metallic calcium. The calcium chloride reduces the melting point and thereby decreases the viscosity of the molten mixture. The calcium reduces any oxidized plutonium in the mixture and also causes the dispersed plutonium metal to coalesce and settle out as a separate metallic phase at the bottom of the reaction vessel. Upon cooling the mixture to room temperature, the solid plutonium can be cleanly separated from the overlying solid slag, with an average recovery yield on the order of 96 percent.

Zinc

MedlinePlus

... Using toothpastes containing zinc, with or without an antibacterial agent, appears to prevent plaque and gingivitis. Some ... is some evidence that zinc has some antiviral activity against the herpes virus. Low zinc levels can ...

SEPARATION OF URANIUM, PLUTONIUM AND FISSION PRODUCTS

DOEpatents

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

1959-10-13

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

Method for dissolving delta-phase plutonium

DOEpatents

Karraker, David G.

1992-01-01

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.

SULFIDE METHOD PLUTONIUM SEPARATION

DOEpatents

Duffield, R.B.

1958-08-12

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

Volatile Impurities in the Plutonium Immobilization Ceramic Wasteform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cozzi, A.D.

1999-10-15

Approximately 18 of the 50 metric tons of plutonium identified for disposition contain significant quantities of impurities. A ceramic waste form is the chosen option for immobilization of the excess plutonium. The impurities associated with the stored plutonium have been identified (CaCl2, MgF2, Pb, etc.). For this study, only volatile species are investigated. The impurities are added individually. Cerium is used as the surrogate for plutonium. Three compositions, including the baseline composition, were used to verify the ability of the ceramic wasteform to accommodate impurities. The criteria for evaluation of the effect of the impurities were the apparent porosity andmore » phase assemblage of sintered pellets.« less

PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS

DOEpatents

Sutton, J.B.

1958-02-18

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

Metal stable isotopes in weathering and hydrology: Chapter 10

USGS Publications Warehouse

Bullen, Thomas D.; Holland, Heinrich; Turekian, K.

2014-01-01

This chapter highlights some of the major developments in the understanding of the causes of metal stable isotope compositional variability in and isotope fractionation between natural materials and provides numerous examples of how that understanding is providing new insights into weathering and hydrology. At this stage, our knowledge of causes of stable isotope compositional variability among natural materials is greatest for the metals lithium, magnesium, calcium, and iron, the isotopes of which have already provided important information on weathering and hydrological processes. Stable isotope compositional variability for other metals such as strontium, copper, zinc, chromium, barium, molybdenum, mercury, cadmium, and nickel has been demonstrated but is only beginning to be applied to questions related to weathering and hydrology, and several research groups are currently exploring the potential. And then there are other metals such as titanium, vanadium, rhenium, and tungsten that have yet to be explored for variability of stable isotope composition in natural materials, but which may hold untold surprises in their utility. This impressive list of metals having either demonstrated or potential stable isotope signals that could be used to address important unsolved questions related to weathering and hydrology, constitutes a powerful toolbox that will be increasingly utilized in the coming decades.

BASIC PEROXIDE PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINANTS

DOEpatents

Seaborg, G.T.; Perlman, I.

1959-02-10

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

23. AERIAL VIEW LOOKING SOUTHEAST AT THE PLUTONIUM OPERATION BUILDINGS ...

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

23. AERIAL VIEW LOOKING SOUTHEAST AT THE PLUTONIUM OPERATION BUILDINGS 771, 776/777, AND 707. BUILDING 771, IN THE FOREGROUND, WAS BUILT IN 1952 TO HOUSE ALL PLUTONIUM OPERATIONS. BY 1956, BUILDING 771 WAS NO LONGER ADEQUATE FOR PRODUCTION DEMANDS. BUILDING 776/777, TO THE SOUTH OF BUILDING 771, WAS CONSTRUCTED TO HOUSE PLUTONIUM FABRICATION AND FOUNDRY OPERATIONS. PLUTONIUM RECOVERY REMAINED IN BUILDING 771. BY 1967, CONSTRUCTION ON BUILDING 707, TO THE SOUTH OF BUILDING 776/777, BEGAN AS PRODUCTION LEVELS CONTINUED TO EXPAND NECESSITATING THE NEED FOR ADDITIONAL PLUTONIUM FABRICATION SPACE (7/1/69). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

COLUMBIC OXIDE ADSORPTION PROCESS FOR SEPARATING URANIUM AND PLUTONIUM IONS

DOEpatents

Beaton, R.H.

1959-07-14

A process is described for separating plutonium ions from a solution of neutron irradiated uranium in which columbic oxide is used as an adsorbert. According to the invention the plutonium ion is selectively adsorbed by Passing a solution containing the plutonium in a valence state not higher than 4 through a porous bed or column of granules of hydrated columbic oxide. The adsorbed plutonium is then desorbed by elution with 3 N nitric acid.

[Improvement in zinc nutrition due to zinc transporter-targeting strategy].

PubMed

Kambe, Taiho

2016-07-01

Adequate intake of zinc from the daily diet is indispensable to maintain health. However, the dietary zinc content often fails to fulfill the recommended daily intake, leading to zinc deficiency and also increases the risk of developing chronic diseases, particularly in elderly individuals. Therefore, increased attention is required to overcome zinc deficiency and it is important to improve zinc nutrition in daily life. In the small intestine, the zinc transporter, ZIP4, functions as a component that is essential for zinc absorption. In this manuscript, we present a brief overview regarding zinc deficiency. Moreover, we review a novel strategy, called "ZIP4-targeting", which has the potential to enable efficient zinc absorption from the diet. ZIP4-targeting strategy is possibly a major step in preventing zinc deficiency and improving human health.

Kinetic control on Zn isotope signatures recorded in marine diatoms

NASA Astrophysics Data System (ADS)

Köbberich, Michael; Vance, Derek

2017-08-01

Marine diatoms dominate the oceanic cycle of the essential micronutrient zinc (Zn). The stable isotopes of zinc and other metals are increasingly used to understand trace metal micronutrient cycling in the oceans. One clear feature of the early isotope data is the heavy Zn isotope signature of the average oceanic dissolved pool relative to the inputs, potentially driven by uptake of light isotopes into phytoplankton cells and export to sediments. However, despite the fact that diatoms strip Zn from surface waters across the Antarctic polar front in the Southern Ocean, the local upper ocean is not isotopically heavy. Here we use culturing experiments to quantify the extent of Zn isotope fractionation by diatoms and to elucidate the mechanisms driving it. We have cultured two different open-ocean diatom species (T. oceanica and Chaetoceros sp.) in a series of experiments at constant medium Zn concentration but at bioavailable medium Fe ranging from limiting to replete. We find that T. oceanica can maintain high growth rates and Zn uptake rates over the full range of bioavailable iron (Fe) investigated, and that the Zn taken up has a δ66Zn that is unfractionated relative to that of the bioavailable free Zn in the medium. The studied representative of the genus Chaetoceros, on the other hand, shows more significantly reduced Zn uptake rates at low Fe and records more variable biomass δ66Zn signatures, of up to 0.85‰ heavier than the medium. We interpret the preferential uptake of heavy isotopes at extremely low Zn uptake rates as potentially due to either of the following two mechanisms. First, the release of extracellular polymeric substances (EPS), at low Fe levels, may preferentially scavenge heavy Zn isotopes. Second, the Zn uptake rate may be slow enough to establish pseudo-equilibrium conditions at the transporter site, with heavy Zn isotopes forming more stable surface complexes. Thus we find that, in our experiments, Fe-limitation exerts a key control that

Plutonium and americium in the foodchain lichen-reindeer-man

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaakkola, T.; Hakanen, M.; Keinonen, M.

1977-01-01

The atmospheric nuclear tests have produced a worldwide fallout of transuranium elements. In addition to plutonium measurable concentrations of americium are to be found in terrestrial and aquatic environments. The metabolism of plutonium in reindeer was investigated by analyzing plutonium in liver, bone, and lung collected during 1963-1976. To determine the distribution of plutonium in reindeer all tissues of four animals of different ages were analyzed. To estimate the uptake of plutonium from the gastrointestinal tract in reindeer, the tissue samples of elk were also analyzed. Elk which is of the same genus as reindeer does not feed on lichenmore » but mainly on deciduous plants, buds, young twigs, and leaves of trees and bushes. The composition of its feed corresponds fairly well to that of reindeer during the summer. Studies on behaviour of americium along the foodchain lichen-reindeer-man were started by determining the Am-241 concentrations in lichen and reindeer liver. The Am-241 results were compared with those of Pu-239,240. The plutonium contents of the southern Finns, whose diet does not contain reindeer tissues, were determined by analyzing autopsy tissue samples (liver, lung, and bone). The southern Finns form a control group to the Lapps consuming reindeer tissues. Plutonium analyses of the placenta, blood, and tooth samples of the Lapps were performed.« less

PROCESS OF ELIMINATING HYDROGEN PEROXIDE IN SOLUTIONS CONTAINING PLUTONIUM VALUES

DOEpatents

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

1960-09-27

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

Spatially resolved analysis of plutonium isotopic signatures in environmental particle samples by laser ablation-MC-ICP-MS.

PubMed

Konegger-Kappel, Stefanie; Prohaska, Thomas

2016-01-01

Laser ablation-multi-collector-inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) was optimized and investigated with respect to its performance for determining spatially resolved Pu isotopic signatures within radioactive fuel particle clusters. Fuel particles had been emitted from the Chernobyl nuclear power plant (ChNPP) where the 1986 accident occurred and were deposited in the surrounding soil, where weathering processes caused their transformation into radioactive clusters, so-called micro-samples. The size of the investigated micro-samples, which showed surface alpha activities below 40 mBq, ranged from about 200 to 1000 μm. Direct single static point ablations allowed to identify variations of Pu isotopic signatures not only between distinct fuel particle clusters but also within individual clusters. The resolution was limited to 100 to 120 μm as a result of the applied laser ablation spot sizes and the resolving power of the nuclear track radiography methodology that was applied for particle pre-selection. The determined (242)Pu/(239)Pu and (240)Pu/(239)Pu isotope ratios showed a variation from low to high Pu isotope ratios, ranging from 0.007(2) to 0.047(8) for (242)Pu/(239)Pu and from 0.183(13) to 0.577(40) for (240)Pu/(239)Pu. In contrast to other studies, the applied methodology allowed for the first time to display the Pu isotopic distribution in the Chernobyl fallout, which reflects the differences in the spent fuel composition over the reactor core. The measured Pu isotopic signatures are in good agreement with the expected Pu isotopic composition distribution that is typical for a RBMK-1000 reactor, indicating that the analyzed samples are originating from the ill-fated Chernobyl reactor. The average Pu isotope ratios [(240)Pu/(239)Pu = 0.388(86), (242)Pu/(239)Pu = 0.028(11)] that were calculated from all investigated samples (n = 48) correspond well to previously published results of Pu analyses in contaminated samples from

Radiation from plutonium 238 used in space applications

NASA Technical Reports Server (NTRS)

Keenan, T. K.; Vallee, R. E.; Powers, J. A.

1972-01-01

The principal mode of the nuclear decay of plutonium 238 is by alpha particle emission at a rate of 17 curies per gram. Gamma radiation also present in nuclear fuels arises primarily from the nuclear de-excitation of daughter nuclei as a result of the alpha decay of plutonium 238 and reactor-produced impurities. Plutonium 238 has a spontaneous fission half life of 4.8 x 10 to the 10th power years. Neutrons associated with this spontaneous fission are emitted at a rate of 28,000 neutrons per second per gram. Since the space fuel form of plutonium 238 is the oxide pressed into a cermet with molybdenum, a contribution to the neutron emission rate arises from (alpha, n) reactions with 0-17 and 0-18 which occur in natural oxygen.

Stabilization and immobilization of military plutonium: A non-proliferation perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leventhal, P.

1996-05-01

The Nuclear Control Institute welcomes this DOE-sponsored technical workshop on stabilization and immobilization of weapons plutonium (W Pu) because of the significant contribution it can make toward the ultimate non-proliferation objective of eliminating weapons-usable nuclear material, plutonium and highly enriched uranium (HEU), from world commerce. The risk of theft or diversion of these materials warrants concern, as only a few kilograms in the hands of terrorists or threshold states would give them the capability to build nuclear weapons. Military plutonium disposition questions cannot be addressed in isolation from civilian plutonium issues. The National Academy of Sciences has urged that {open_quotes}furthermore » steps should be taken to reduce the proliferation risks posed by all of the world`s plutonium stocks, military and civilian, separated and unseparated...{close_quotes}. This report discusses vitrification and a mixed oxide fuels option, and the effects of disposition choices on civilian plutonium fuel cycles.« less

Isotopic evidence of plutonium release into the environment from the Fukushima DNPP accident

PubMed Central

Zheng, Jian; Tagami, Keiko; Watanabe, Yoshito; Uchida, Shigeo; Aono, Tatsuo; Ishii, Nobuyoshi; Yoshida, Satoshi; Kubota, Yoshihisa; Fuma, Shoichi; Ihara, Sadao

2012-01-01

The Fukushima Daiichi nuclear power plant (DNPP) accident caused massive releases of radioactivity into the environment. The released highly volatile fission products, such as 129mTe, 131I, 134Cs, 136Cs and 137Cs were found to be widely distributed in Fukushima and its adjacent prefectures in eastern Japan. However, the release of non-volatile actinides, in particular, Pu isotopes remains uncertain almost one year after the accident. Here we report the isotopic evidence for the release of Pu into the atmosphere and deposition on the ground in northwest and south of the Fukushima DNPP in the 20–30 km zones. The high activity ratio of 241Pu/239+240Pu (> 100) from the Fukushima DNPP accident highlights the need for long-term 241Pu dose assessment, and the ingrowth of 241Am. The results are important for the estimation of reactor damage and have significant implication in the strategy of decontamination. PMID:22403743

Radiation damage and annealing in plutonium tetrafluoride

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCoy, Kaylyn; Casella, Amanda; Sinkov, Sergey

Plutonium tetrafluoride that was separated prior to 1966 at the Hanford Site in Washington State was analyzed at the Pacific Northwest National Laboratory (PNNL) in 2015 and 2016. The plutonium tetrafluoride, as received, was an off-normal color and considering the age of the plutonium, there were questions about the condition of the material. These questions had to be answered in order to determine the suitability of the material for future use or long-term storage. Therefore, Thermogravimetric/Differential Thermal Analysis and X-ray Diffraction evaluations were conducted to determine the plutonium’s crystal structure, oxide content, and moisture content; these analyses reported that themore » plutonium was predominately amorphous and tetrafluoride, with an oxide content near ten percent. Freshly fluorinated plutonium tetrafluoride is known to be monoclinic. During the initial Thermogravimetric/Differential Thermal analyses, it was discovered that an exothermic event occurred within the material near 414°C. X-ray Diffraction analyses were conducted on the annealed tetrafluoride. The X-ray Diffraction analyses indicated that some degree of recrystallization occurred in conjunction with the 414°C event. The following commentary describes the series of Thermogravimetric/Differential Thermal and X-ray Diffraction analyses that were conducted as part of this investigation at PNNL, in collaboration with the University of Utah Nuclear Engineering Program.« less

Improved zinc electrode and rechargeable zinc-air battery

DOEpatents

Ross, P.N. Jr.

1988-06-21

The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

Upregulation of Zinc Absorption Matches Increases in Physiologic Requirements for Zinc in Women Consuming High- or Moderate-Phytate Diets during Late Pregnancy and Early Lactation.

PubMed

Hambidge, K Michael; Miller, Leland V; Mazariegos, Manolo; Westcott, Jamie; Solomons, Noel W; Raboy, Victor; Kemp, Jennifer F; Das, Abhik; Goco, Norman; Hartwell, Ty; Wright, Linda; Krebs, Nancy F

2017-06-01

Background: Estimated physiologic requirements (PRs) for zinc increase in late pregnancy and early lactation, but the effect on dietary zinc requirements is uncertain. Objective: The aim of this study was to determine changes in daily fractional absorbed zinc and total absorbed zinc (TAZ) from ad libitum diets of differing phytate contents in relation to physiologic zinc requirements during pregnancy and lactation. Methods: This was a prospective observational study of zinc absorption at 8 (phase 1) and 34 (phase 2) wk of gestation and 2 (phase 3) and 6 (phase 4) mo of lactation. Participants were indigenous Guatemalan women of childbearing age whose major food staple was maize and who had been randomly assigned in a larger study to either of 2 ad libitum feeding groups: low-phytate maize (LP; 1.6 mg/g; n = 14) or control maize (C; 7.1 mg/g; n = 8). Total dietary zinc (milligrams per day, TDZ) and phytate (milligrams per day) were determined from duplicate diets and fractional absorption (FAZ) by dual isotope ratio technique (TAZ = TDZ × FAZ). All variables were examined longitudinally and by group and compared with PRs. TAZ values at later phases were compared with phase 1. Measured TAZ was compared with predicted TAZ for nonpregnant, nonlactating (NPNL) women. Results: TAZ was greater in the LP group than in the C group at all phases. All variables increased from phase 1 to phases 2 and 3 and declined at phase 4. TAZ increased by 1.25 mg/d ( P = 0.045) in the C group and by 0.81 mg/d ( P = 0.058) in the LP group at phase 2. At phase 3, the increases were 2.66 mg/d ( P = 0.002) in the C group and 2.28 mg/d ( P = 0.0004) in the LP group, compared with a 1.37-mg/d increase in PR. Measured TAZ was greater than predicted values in phases 2-4. Conclusions: Upregulation of zinc absorption in late pregnancy and early lactation matches increases in PRs of pregnant and lactating women, regardless of dietary phytate, which has implications for dietary zinc requirements of

Plutonium release from the 903 pad at Rocky Flats.

PubMed

Mongan, T R; Ripple, S R; Winges, K D

1996-10-01

The Colorado Department of Public Health and Environment (CDH) sponsored a study to reconstruct contaminant doses to the public from operations at the Rocky Flats nuclear weapons plant. This analysis of the accidental release of plutonium from the area known as the 903 Pad is part of the CDH study. In the 1950's and 1960's, 55-gallon drums of waste oil contaminated with plutonium, and uranium were stored outdoors at the 903 Pad. The drums corroded, leaking contaminated oil onto soil subsequently carried off-site by the wind. The plutonium release is estimated using environmental data from the 1960's and 1970's and an atmospheric transport model for fugitive dust. The best estimate of total plutonium release to areas beyond plant-owned property is about 0.26 TBq (7 Ci). Off-site airborne concentrations and deposition of plutonium are estimated for dose calculation purposes. The best estimate of the highest predicted off-site effective dose is approximately 72 microSv (7.2 mrem).

Isotopic signatures: An important tool in today`s world

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rokop, D.J.; Efurd, D.W.; Benjamin, T.M.

1995-12-01

High-sensitivity/high-accuracy actinide measurement techniques developed to support weapons diagnostic capabilities at the Los Alamos National Laboratory are now being used for environmental monitoring. The measurement techniques used are Thermal Ionization Mass Spectrometry (TIMS), Alpha Spectrometry(AS), and High Resolution Gamma Spectrometry(HRGS). These techniques are used to address a wide variety of actinide inventory issues: Environmental surveillance, site characterizations, food chain member determination, sedimentary records of activities, and treaty compliance concerns. As little as 10 femtograms of plutonium can be detected in samples and isotopic signatures determined on samples containing sub-100 femtogram amounts. Uranium, present in all environmental samples, can generally yieldmore » isotopic signatures of anthropogenic origin when present at the 40 picogam/gram level. Solid samples (soils, sediments, fauna, and tissue) can range from a few particles to several kilograms in size. Water samples can range from a few milliliters to as much as 200 liters.« less

METHOD OF SEPARATING PLUTONIUM FROM LANTHANUM FLUORIDE CARRIER

DOEpatents

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

1958-06-10

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

Assessing the dietary bioavailability of metals associated with natural particles: Extending the use of the reverse labeling approach to zinc

USGS Publications Warehouse

Croteau, Marie-Noele; Cain, Daniel J.; Fuller, Christopher C.

2017-01-01

We extend the use of a novel tracing technique to quantify the bioavailability of zinc (Zn) associated with natural particles using snails enriched with a less common Zn stable isotope. Lymnaea stagnalis is a model species that has relatively fast Zn uptake rates from the dissolved phase, enabling their rapid enrichment in 67Zn during the initial phase of labeling. Isotopically enriched snails were subsequently exposed to algae mixed with increasing amounts of metal-rich particles collected from two acid mine drainage impacted rivers. Zinc bioavailability from the natural particles was inferred from calculations of 66Zn assimilation into the snail’s soft tissues. Zinc assimilation efficiency (AE) varied from 28% for the Animas River particles to 45% for the Snake River particles, indicating that particle-bound, or sorbed Zn, was bioavailable from acid mine drainage wastes. The relative binding strength of Zn sorption to the natural particles was inversely related to Zn bioavailability; a finding that would not have been possible without using the reverse labeling approach. Differences in the chemical composition of the particles suggest that their geochemical properties may influence the extent of Zn bioavailability.

Assessing the Dietary Bioavailability of Metals Associated with Natural Particles: Extending the Use of the Reverse Labeling Approach to Zinc.

PubMed

Croteau, Marie-Noële; Cain, Daniel J; Fuller, Christopher C

2017-03-07

We extend the use of a novel tracing technique to quantify the bioavailability of zinc (Zn) associated with natural particles using snails enriched with a less common Zn stable isotope. Lymnaea stagnalis is a model species that has relatively fast Zn uptake rates from the dissolved phase, enabling their rapid enrichment in 67 Zn during the initial phase of labeling. Isotopically enriched snails were subsequently exposed to algae mixed with increasing amounts of metal-rich particles collected from two acid mine drainage impacted rivers. Zinc bioavailability from the natural particles was inferred from calculations of 66 Zn assimilation into the snail's soft tissues. Zinc assimilation efficiency (AE) varied from 28% for the Animas River particles to 45% for the Snake River particles, indicating that particle-bound, or sorbed Zn, was bioavailable from acid mine drainage wastes. The relative binding strength of Zn sorption to the natural particles was inversely related to Zn bioavailability; a finding that would not have been possible without using the reverse labeling approach. Differences in the chemical composition of the particles suggest that their geochemical properties may influence the extent of Zn bioavailability.

Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

PubMed

Kessels, Jana Elena; Wessels, Inga; Haase, Hajo; Rink, Lothar; Uciechowski, Peter

2016-09-01

The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2'-deoxycytidine (AZA) increased intracellular (after 24 and 48h) and total cellular zinc levels (after 48h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48h. MT mRNA was significantly enhanced after 24h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells. Copyright © 2016 Elsevier GmbH. All rights reserved.

Heterogeneity Effects in Plutonium Contaminated Soil

DTIC Science & Technology

2009-03-01

masses up to one kilogram once the ratio of Americium - 241 (Am- 241 ) and plutonium concentrations was established (Rademacher, 2001). Alpha...with a sample number and tared weight with a non-smearing marker. A standard control was then set using a point source of Americium - 241 on an aluminum...During the fire the weapons grade plutonium (Pu- 239, Pu-240, and Pu- 241 ) ignited and was released into the surrounding area, due to both

Neutron radiation characteristics of plutonium dioxide fuel

NASA Technical Reports Server (NTRS)

Taherzadeh, M.

1972-01-01

The major sources of neutrons from plutonium dioxide nuclear fuel are considered in detail. These sources include spontaneous fission of several of the Pu isotopes, (alpha, n) reactions with low Z impurities in the fuel, and (alpha, n) reactions with O-18. For spontaneous fission neutrons a value of (1.95 + or - 0.07) X 1,000 n/s/g PuO2 is obtained. The neutron yield from (alpha, n) reactions with oxygen is calculated by integrating the reaction rate equation over all alpha-particle energies and all center-of-mass angles. The results indicate a neutron emission rate of (1.14 + or - 0.26) X 10,000 n/s/g PuO2. The neutron yield from (alpha, n) reactions with low Z impurities in the fuel is presented in tabular form for one part part per million of each impurity. The total neutron yield due to the combined effects of all the impurities depends upon the fractional weight concentration of each impurity. The total neutron flux emitted from a particular fuel geometry is estimated by adding the neutron yield due to the induced fission to the other neutron sources.

URANOUS IODATE AS A CARRIER FOR PLUTONIUM

DOEpatents

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

1959-12-15

A process is described for precipitating plutonium on a uranous iodate carrier from an aqueous acid solution conA plutonium solution more concentrated than the original solution can then be obtained by oxidizing the uranium to the hexavalent state and dissolving the precipitate, after separating the latter from the original solution, by means of warm nitric acid.

PROCESS FOR SEPARATING PLUTONIUM BY REPEATED PRECIPITATION WITH AMPHOTERIC HYDROXIDE CARRIERS

DOEpatents

Faris, B.F.

1960-04-01

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

SEPARATION OF PLUTONIUM FROM AQUEOUS SOLUTIONS BY ION-EXCHANGE

DOEpatents

Schubert, J.

1958-06-01

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

Measurement of total Zn and Zn isotope ratios by quadrupole ICP-MS for evaluation of Zn uptake in gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss)

USGS Publications Warehouse

Wolf, R.E.; Todd, A.S.; Brinkman, S.; Lamothe, P.J.; Smith, K.S.; Ranville, J.F.

2009-01-01

This study evaluates the potential use of stable zinc isotopes in toxicity studies measuring zinc uptake by the gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The use of stable isotopes in such studies has several advantages over the use of radioisotopes, including cost, ease of handling, elimination of permit requirements, and waste disposal. A pilot study using brown trout was performed to evaluate sample preparation methods and the ability of a quadrupole inductively coupled plasma mass spectrometer (ICP-MS) system to successfully measure changes in the 67Zn/66Zn ratios for planned exposure levels and duration. After completion of the pilot study, a full-scale zinc exposure study using rainbow trout was performed. The results of these studies indicate that there are several factors that affect the precision of the measured 67Zn/66Zn ratios in the sample digests, including variations in sample size, endogenous zinc levels, and zinc uptake rates by individual fish. However, since these factors were incorporated in the calculation of the total zinc accumulated by the gills during the exposures, the data obtained were adequate for their intended use in calculating zinc binding and evaluating the influences of differences in water quality parameters.

Method of capturing or trapping zinc using zinc getter materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunyadi Murph, Simona E.; Korinko, Paul S.

2017-07-11

A method of trapping or capturing zinc is disclosed. In particular, the method comprises a step of contacting a zinc vapor with a zinc getter material. The zinc getter material comprises nanoparticles and a metal substrate.

HB-Line Plutonium Oxide Data Collection Strategy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watkins, R.; Varble, J.; Jordan, J.

2015-05-26

HB-Line and H-Canyon will handle and process plutonium material to produce plutonium oxide for feed to the Mixed Oxide Fuel Fabrication Facility (MFFF). However, the plutonium oxide product will not be transferred to the MFFF directly from HB-Line until it is packaged into a qualified DOE-STD-3013-2012 container. In the interim, HB-Line will load plutonium oxide into an inner, filtered can. The inner can will be placed in a filtered bag, which will be loaded into a filtered outer can. The outer can will be loaded into a certified 9975 with getter assembly in compliance with onsite transportation requirement, for subsequentmore » storage and transfer to the K-Area Complex (KAC). After DOE-STD-3013-2012 container packaging capabilities are established, the product will be returned to HB-Line to be packaged into a qualified DOE-STD-3013-2012 container. To support the transfer of plutonium oxide to KAC and then eventually to MFFF, various material and packaging data will have to be collected and retained. In addition, data from initial HB-Line processing operations will be needed to support future DOE-STD-3013-2012 qualification as amended by the HB-Line DOE Standard equivalency. As production increases, the volume of data to collect will increase. The HB-Line data collected will be in the form of paper copies and electronic media. Paper copy data will, at a minimum, consist of facility procedures, nonconformance reports (NCRs), and DCS print outs. Electronic data will be in the form of Adobe portable document formats (PDFs). Collecting all the required data for each plutonium oxide can will be no small effort for HB-Line, and will become more challenging once the maximum annual oxide production throughput is achieved due to the sheer volume of data to be collected. The majority of the data collected will be in the form of facility procedures, DCS print outs, and laboratory results. To facilitate complete collection of this data, a traveler form will be developed

Survey of glass plutonium contents and poison selection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plodinec, M.J.; Ramsey, W.G.; Ellison, A.J.G.

1996-05-01

If plutonium and other actinides are to be immobilized in glass, then achieving high concentrations in the glass is desirable. This will lead to reduced costs and more rapid immobilization. However, glasses with high actinide concentrations also bring with them undersirable characteristics, especially a greater concern about nuclear criticality, particularly in a geologic repository. The key to achieving a high concentration of actinide elements in a glass is to formulate the glass so that the solubility of actinides is high. At the same time, the glass must be formulated so that the glass also contains neutron poisons, which will preventmore » criticality during processing and in a geologic repository. In this paper, the solubility of actinides, particularly plutonium, in three types of glasses are discussed. Plutonium solubilities are in the 2-4 wt% range for borosilicate high-level waste (HLW) glasses of the type which will be produced in the US. This type of glass is generally melted at relatively low temperatures, ca. 1150{degrees}C. For this melting temperature, the glass can be reformulated to achieve plutonium solubilities of at least 7 wt%. This low melting temperature is desirable if one must retain volatile cesium-137 in the glass. If one is not concerned about cesium volatility, then glasses can be formulated which can contain much larger amounts of plutonium and other actinides. Plutonium concentrations of at least 15 wt% have been achieved. Thus, there is confidence that high ({ge}5 wt%) concentrations of actinides can be achieved under a variety of conditions.« less

30. VIEW OF A GLOVEBOX LINE USED IN PLUTONIUM OPERATIONS. ...

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

30. VIEW OF A GLOVEBOX LINE USED IN PLUTONIUM OPERATIONS. SAFETY AND HEALTH CONCERNS WERE OF MAJOR IMPORTANCE AT THE PLANT, BECAUSE OF THE RADIOACTIVE NATURE OF THE MATERIALS USED. PLUTONIUM GIVES OFF ALPHA AND BETA PARTICLES, GAMMA PROTONS, NEUTRONS, AND IS ALSO PYROPHORIC. AS A RESULT, PLUTONIUM OPERATIONS ARE PERFORMED UNDER CONTROLLED CONDITIONS THAT INCLUDE CONTAINMENT, FILTERING, SHIELDING, AND CREATING AN INERT ATMOSPHERE. PLUTONIUM WAS HANDLED WITHIN GLOVEBOXES THAT WERE INTERCONNECTED AND RAN SEVERAL HUNDRED FEET IN LENGTH (5/5/70). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO

Stable isotopes of transition and post-transition metals as tracers in environmental studies

USGS Publications Warehouse

Bullen, Thomas D.; Baskaran, Mark

2011-01-01

The transition and post-transition metals, which include the elements in Groups 3–12 of the Periodic Table, have a broad range of geological and biological roles as well as industrial applications and thus are widespread in the environment. Interdisciplinary research over the past decade has resulted in a broad understanding of the isotope systematics of this important group of elements and revealed largely unexpected variability in isotope composition for natural materials. Significant kinetic and equilibrium isotope fractionation has been observed for redox sensitive metals such as iron, chromium, copper, molybdenum and mercury, and for metals that are not redox sensitive in nature such as cadmium and zinc. In the environmental sciences, the isotopes are increasingly being used to understand important issues such as tracing of metal contaminant sources and fates, unraveling metal redox cycles, deciphering metal nutrient pathways and cycles, and developing isotope biosignatures that can indicate the role of biological activity in ancient and modern planetary systems.

METHOD OF SEPARATION OF PLUTONIUM FROM CARRIER PRECIPITATES

DOEpatents

Dawson, I.R.

1959-09-22

The recovery of plutonium from fluoride carrier precipitates is described. The precipitate is dissolved in zirconyl nitrate, ferric nitrate, aluminum nitrate, or a mixture of these complexing agents, and the plutonium is then extracted from the aqueous solution formed with a water-immiscible organic solvent.

Sub-micron Hard X-ray Fluorescence Imaging of Synthetic Elements

PubMed Central

Jensen, Mark P.; Aryal, Baikuntha P.; Gorman-Lewis, Drew; Paunesku, Tatjana; Lai, Barry; Vogt, Stefan; Woloschak, Gayle E.

2013-01-01

Synchrotron-based X-ray fluorescence microscopy (SXFM) using hard X-rays focused into sub-micron spots is a powerful technique for elemental quantification and mapping, as well as microspectroscopic measurement such as μ-XANES (X-ray absorption near edge structure). We have used SXFM to image and simultaneously quantify the transuranic element plutonium at the L3 or L2 edge as well as lighter biologically essential elements in individual rat pheochromocytoma (PC12) cells after exposure to the long-lived plutonium isotope 242Pu. Elemental maps reveal that plutonium localizes principally in the cytoplasm of the cells and avoids the cell nucleus, which is marked by the highest concentrations of phosphorus and zinc, under the conditions of our experiments. The minimum detection limit under typical acquisition conditions for an average 202 μm2 cell is 1.4 fg Pu/cell or 2.9 × 10−20 moles Pu/μm2, which is similar to the detection limit of K-edge SXFM of transition metals at 10 keV. Copper electron microscopy grids were used to avoid interference from gold X-ray emissions, but traces of strontium present in naturally occurring calcium can still interfere with plutonium detection using its Lα X-ray emission. PMID:22444530

PLUTONIUM RECOVERY FROM NEUTRON-BOMBARDED URANIUM FUEL

DOEpatents

Moore, R.H.

1964-03-24

A process of recovering plutonium from fuel by dissolution in molten KAlCl/sub 4/ double salt is described. Molten lithium chloride plus stannous chloride is added to reduce plutonium tetrachloride to the trichloride, which is dissolved in a lithium chloride phase while the uranium, as the tetrachloride, is dissolved in a double-salt phase. Separation of the two phases is discussed. (AEC)

Compilation of minimum and maximum isotope ratios of selected elements in naturally occurring terrestrial materials and reagents

USGS Publications Warehouse

Coplen, T.B.; Hopple, J.A.; Böhlke, J.K.; Peiser, H.S.; Rieder, S.E.; Krouse, H.R.; Rosman, K.J.R.; Ding, T.; Vocke, R.D.; Revesz, K.M.; Lamberty, A.; Taylor, P.; De Bievre, P.

2002-01-01

Documented variations in the isotopic compositions of some chemical elements are responsible for expanded uncertainties in the standard atomic weights published by the Commission on Atomic Weights and Isotopic Abundances of the International Union of Pure and Applied Chemistry. This report summarizes reported variations in the isotopic compositions of 20 elements that are due to physical and chemical fractionation processes (not due to radioactive decay) and their effects on the standard atomic weight uncertainties. For 11 of those elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulfur, chlorine, copper, and selenium), standard atomic weight uncertainties have been assigned values that are substantially larger than analytical uncertainties because of common isotope abundance variations in materials of natural terrestrial origin. For 2 elements (chromium and thallium), recently reported isotope abundance variations potentially are large enough to result in future expansion of their atomic weight uncertainties. For 7 elements (magnesium, calcium, iron, zinc, molybdenum, palladium, and tellurium), documented isotope-abundance variations in materials of natural terrestrial origin are too small to have a significant effect on their standard atomic weight uncertainties. This compilation indicates the extent to which the atomic weight of an element in a given material may differ from the standard atomic weight of the element. For most elements given above, data are graphically illustrated by a diagram in which the materials are specified in the ordinate and the compositional ranges are plotted along the abscissa in scales of (1) atomic weight, (2) mole fraction of a selected isotope, and (3) delta value of a selected isotope ratio. There are no internationally distributed isotopic reference materials for the elements zinc, selenium, molybdenum, palladium, and tellurium. Preparation of such materials will help to make isotope ratio measurements among

Zinc in human health: effect of zinc on immune cells.

PubMed

Prasad, Ananda S

2008-01-01

Although the essentiality of zinc for plants and animals has been known for many decades, the essentiality of zinc for humans was recognized only 40 years ago in the Middle East. The zinc-deficient patients had severe immune dysfunctions, inasmuch as they died of intercurrent infections by the time they were 25 years of age. In our studies in an experimental human model of zinc deficiency, we documented decreased serum testosterone level, oligospermia, severe immune dysfunctions mainly affecting T helper cells, hyperammonemia, neurosensory disorders, and decreased lean body mass. It appears that zinc deficiency is prevalent in the developing world and as many as two billion subjects may be growth retarded due to zinc deficiency. Besides growth retardation and immune dysfunctions, cognitive impairment due to zinc deficiency also has been reported recently. Our studies in the cell culture models showed that the activation of many zinc-dependent enzymes and transcription factors were adversely affected due to zinc deficiency. In HUT-78 (T helper 0 [Th(0)] cell line), we showed that a decrease in gene expression of interleukin-2 (IL-2) and IL-2 receptor alpha(IL-2Ralpha) were due to decreased activation of nuclear factor-kappaB (NF-kappaB) in zinc deficient cells. Decreased NF-kappaB activation in HUT-78 due to zinc deficiency was due to decreased binding of NF-kappaB to DNA, decreased level of NF-kappaB p105 (the precursor of NF-kappaB p50) mRNA, decreased kappaB inhibitory protein (IkappaB) phosphorylation, and decreased Ikappa kappa. These effects of zinc were cell specific. Zinc also is an antioxidant and has anti-inflammatory actions. The therapeutic roles of zinc in acute infantile diarrhea, acrodermatitis enteropathica, prevention of blindness in patients with age-related macular degeneration, and treatment of common cold with zinc have been reported. In HL-60 cells (promyelocytic leukemia cell line), zinc enhances the up-regulation of A20 mRNA, which, via TRAF

Efficacy of highly bioavailable zinc from fortified water: a randomized controlled trial in rural Beninese children.

PubMed

Galetti, Valeria; Kujinga, Prosper; Mitchikpè, Comlan Evariste S; Zeder, Christophe; Tay, Fabian; Tossou, Félicien; Hounhouigan, Joseph D; Zimmermann, Michael B; Moretti, Diego

2015-11-01

Zinc deficiency and contaminated water are major contributors to diarrhea in developing countries. Food fortification with zinc has not shown clear benefits, possibly because of low zinc absorption from inhibitory food matrices. We used a novel point-of-use water ultrafiltration device configured with glass zinc plates to produce zinc-fortified, potable water. The objective was to determine zinc bioavailability from filtered water and the efficacy of zinc-fortified water in improving zinc status. In a crossover balanced study, we measured fractional zinc absorption (FAZ) from the zinc-fortified water in 18 healthy Swiss adults using zinc stable isotopes and compared it with zinc-fortified maize porridge. We conducted a 20-wk double-blind randomized controlled trial (RCT) in 277 Beninese school children from rural settings who were randomly assigned to receive a daily portion of zinc-fortified filtered water delivering 2.8 mg Zn (Zn+filter), nonfortified filtered water (Filter), or nonfortified nonfiltered water (Pump) from the local improved supply, acting as the control group. The main outcome was plasma zinc concentration (PZn), and the 3 groups were compared by using mixed-effects models. Secondary outcomes were prevalence of zinc deficiency, diarrhea prevalence, and growth. Geometric mean (-SD, +SD) FAZ was 7-fold higher from fortified water (65.9%; 42.2, 102.4) than from fortified maize (9.1%; 6.0, 13.7; P < 0.001). In the RCT, a significant time-by-treatment effect on PZn (P = 0.026) and on zinc deficiency (P = 0.032) was found; PZn in the Zn+filter group was significantly higher than in the Filter (P = 0.006) and Pump (P = 0.025) groups. We detected no effect on diarrhea or growth, but our study did not have the duration and power to detect such effects. Consumption of filtered water fortified with a low dose of highly bioavailable zinc is an effective intervention in children from rural African settings. Large community-based trials are needed to assess the

COMPLEX FLUORIDES OF PLUTONIUM AND AN ALKALI METAL

DOEpatents

Seaborg, G.T.

1960-08-01

A method is given for precipitating alkali metal plutonium fluorides. such as KPuF/sub 5/, KPu/sub 2/F/sub 9/, NaPuF/sub 5/, and RbPuF/sub 5/, from an aqueous plutonium(IV) solution by adding hydrogen fluoride and alkali-metal- fluoride.

Zinc Fractional Absorption from a Representative Diet in Young Chinese Men and Women of the Shandong Rural Region.

PubMed

Wang, Cuiping; Lin, Xinying; Guo, Dongmei; Ding, Lili; Guo, Haifeng; Xu, Guifa; Cui, Xi; Wang, Xia

2017-05-01

The objective of this study was to investigate the zinc fractional absorption of young Chinese men and women from the Shandong rural region under the routine dietary pattern by stable isotope technique. Ten men and 10 women, aged 20 to 35 years, and with a representative diet during the experiment were recruited from the Shandong rural region. Stable 67 Zn was used as a tracer to label ZnCl 2 , and Yb was used to monitor the excretion of 67 Zn in urine and feces. All volunteers were given rice containing 4.0 mg 67 Zn and 1.0 mg Yb on the fourth day. Then the food and fecal samples of all subjects were collected for 12 consecutive days. The total zinc and the stable zinc isotope ratio of all samples were determined by atomic absorption spectrophotometer and thermal ionization mass spectrometer, respectively. The determination of the other nutrients was performed based on the Chinese National Standard Methods. Among volunteers, the daily intake of zinc was 15.50 mg, 103.33 % of recommended nutrient intake (RNI, set by the Chinese Nutrition Society) in men and 15.43 mg, 134.17 % in women. The fractional absorption of Zn was 23.42 ± 2.23 % in men, and 22.49 ± 2.19 % in women. The protein candidates got from the typical diets was 93.96 % of RNI in women. Calcium and ascorbic acid intakes were 76.23 % of RNI and 27.91 % of RNI in men, respectively and 51.17 % of RNI and 34.23 % of RNI in women, respectively. Our results showed that a typical meal for someone in the Shandong rural region presented an adequate intake of zinc and a moderate Zn bioavailability. The shortage of protein and the inappropriate protein pattern may play important roles in reducing zinc bioavailability.

Copper, iron and zinc absorption, retention and status of young women fed vitamin B-6 deficient diets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turnlund, J.R.; Keyes, W.R.; Hudson, C.A.

1991-03-11

A study was conducted in young women to determine the effect of vitamin B-6 deficient diets on copper, iron and zinc metabolism. Young women were confined to a metabolic research unit for 84 and 98 days. They were fed a vitamin B-6 deficient formula diet initially, followed by food diet containing four increasing levels of vitamin B-6. Copper, iron and zinc absorption, retention and status were determined at intervals throughout the study. Absorption was determined using the stable isotopes {sup 65}Cu, {sup 54}Fe, and {sup 67}Zn. Status was based on serum copper and zinc, hemoglobin, hematocrit and mean corpuscular volume.more » Copper absorption averaged 18 {plus minus} 1% during vitamin B-6 depletion, significantly lower than 24 {plus minus} 1% during repletion, but serum copper was not affected and balance was positive. Iron absorption was not impaired significantly by vitamin B-6 deficient diets, but status declined during the depletion period. Zinc absorption averaged 40 {plus minus} 2% during depletion and 27 {plus minus} 2% during repletion. Zinc absorption and retention were significantly greater during vitamin B-6 depletion, but serum zinc declined suggesting the absorbed zinc was not available for utilization. The results suggest that vitamin B-6 depletion of young women may inhibit copper absorption, affect iron status and alter zinc metabolism. The effects of vitamin B-6 depletion differ markedly among these elements.« less

Electronic structure, phase transitions and diffusive properties of elemental plutonium

NASA Astrophysics Data System (ADS)

Setty, Arun; Cooper, B. R.

2003-03-01

We present a SIC-LDA-LMTO based study of the electronic structure of the delta, alpha and gamma phases of plutonium, and also of the alpha and gamma phases of elemental cerium. We find excellent agreement with the experimental densities and magnetic properties [1]. Furthermore, detailed studies of the computational densities of states for delta plutonium, and comparison with the experimental photoemission spectrum [2], provide evidence for the existence of an unusual fluctuating valence state. Results regarding the vacancy formation and self-diffusion in delta plutonium will be presented. Furthermore, a study of interface diffusion between plutonium and steel (technologically relevant in the storage of spent fuel) or other technologically relevant alloys will be included. Preliminary results regarding gallium stabilization of delta plutonium, and of plutonium alloys will be presented. [1] M. Dormeval et al., private communication (2001). [2] A. J. Arko, J. J. Joyce, L. Morales, J. Wills, and J. Lashley et. al., Phys. Rev. B, 62, 1773 (2000). [3] B. R. Cooper et al, Phil. Mag. B 79, 683 (1999); B.R. Cooper, Los Alamos Science 26, 106 (2000)); B.R. Cooper, A.K. Setty and D.L.Price, to be published.

PLUTONIUM PURIFICATION PROCESS EMPLOYING THORIUM PYROPHOSPHATE CARRIER

DOEpatents

King, E.L.

1959-04-28

The separation and purification of plutonium from the radioactive elements of lower atomic weight is described. The process of this invention comprises forming a 0.5 to 2 M aqueous acidffc solution containing plutonium fons in the tetravalent state and elements with which it is normally contaminated in neutron irradiated uranium, treating the solution with a double thorium compound and a soluble pyrophosphate compound (Na/sub 4/P/sub 2/O/sub 7/) whereby a carrier precipitate of thorium A method is presented of reducing neptunium and - trite is advantageous since it destroys any hydrazine f so that they can be removed from solutions in which they are contained is described. In the carrier precipitation process for the separation of plutonium from uranium and fission products including zirconium and columbium, the precipitated blsmuth phosphate carries some zirconium, columbium, and uranium impurities. According to the invention such impurities can be complexed and removed by dissolving the contaminated carrier precipitate in 10M nitric acid, followed by addition of fluosilicic acid to about 1M, diluting the solution to about 1M in nitric acid, and then adding phosphoric acid to re-precipitate bismuth phosphate carrying plutonium.

PLUTONIUM CARRIER METATHESIS WITH ORGANIC REAGENT

DOEpatents

Thompson, S.G.

1958-07-01

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

The Zinc Transporter Zip5 (Slc39a5) Regulates Intestinal Zinc Excretion and Protects the Pancreas against Zinc Toxicity

PubMed Central

Geiser, Jim; De Lisle, Robert C.; Andrews, Glen K.

2013-01-01

Background ZIP5 localizes to the baso-lateral membranes of intestinal enterocytes and pancreatic acinar cells and is internalized and degraded coordinately in these cell-types during periods of dietary zinc deficiency. These cell-types are thought to control zinc excretion from the body. The baso-lateral localization and zinc-regulation of ZIP5 in these cells are unique among the 14 members of the Slc39a family and suggest that ZIP5 plays a role in zinc excretion. Methods/Principal Findings We created mice with floxed Zip5 genes and deleted this gene in the entire mouse or specifically in enterocytes or acinar cells and then examined the effects on zinc homeostasis. We found that ZIP5 is not essential for growth and viability but total knockout of ZIP5 led to increased zinc in the liver in mice fed a zinc-adequate (ZnA) diet but impaired accumulation of pancreatic zinc in mice fed a zinc-excess (ZnE) diet. Loss-of-function of enterocyte ZIP5, in contrast, led to increased pancreatic zinc in mice fed a ZnA diet and increased abundance of intestinal Zip4 mRNA. Finally, loss-of-function of acinar cell ZIP5 modestly reduced pancreatic zinc in mice fed a ZnA diet but did not impair zinc uptake as measured by the rapid accumulation of 67zinc. Retention of pancreatic 67zinc was impaired in these mice but the absence of pancreatic ZIP5 sensitized them to zinc-induced pancreatitis and exacerbated the formation of large cytoplasmic vacuoles containing secretory protein in acinar cells. Conclusions These studies demonstrate that ZIP5 participates in the control of zinc excretion in mice. Specifically, they reveal a paramount function of intestinal ZIP5 in zinc excretion but suggest a role for pancreatic ZIP5 in zinc accumulation/retention in acinar cells. ZIP5 functions in acinar cells to protect against zinc-induced acute pancreatitis and attenuate the process of zymophagy. This suggests that it may play a role in autophagy. PMID:24303081

METHOD AND MEANS FOR ELECTROLYTIC PURIFICATION OF PLUTONIUM

DOEpatents

Bjorklund, C.W.; Benz, R.; Maraman, W.J.; Leary, J.A.; Walsh, K.A.

1960-02-01

The technique of electrodepositing pure plutonium from a fused salt electrolyte of PuCl/sub 3/ and aixati metal halides is described. When an iron cathode is used, the plutonium deposit alloys therewith in the liquid state at the 400 to 600 deg C operating temperature, such liquid being allowed to drip through holes in the cathode and collect in a massive state in a tantallum cup. The process is adaptable to continuous processing by the use of depleted plutonium fuel as the anode: good to excellent separation from fission products is obtained with a Pu--Fe "fission" anode containing representative fractions of Ce, Ru, Zr, La, Mo, and Nb.

METHOD FOR OBTAINING PLUTONIUM METAL FROM ITS TRICHLORIDE

DOEpatents

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

1962-08-14

A method was developed for obtaining plutonium metal by direct reduction of plutonium chloride, without the use of a booster, using calcium and lanthamum as a reductant, the said reduction being carried out at temperature in the range of 700 to 850 deg C and at about atmospheric pressure. (AEC)

Isotope-abundance variations of selected elements (IUPAC technical report)

USGS Publications Warehouse

Coplen, T.B.; Böhlke, J.K.; De Bievre, P.; Ding, T.; Holden, N.E.; Hopple, J.A.; Krouse, H.R.; Lamberty, A.; Peiser, H.S.; Revesz, K.; Rieder, S.E.; Rosman, K.J.R.; Roth, E.; Taylor, P.D.P.; Vocke, R.D.; Xiao, Y.K.

2002-01-01

Documented variations in the isotopic compositions of some chemical elements are responsible for expanded uncertainties in the standard atomic weights published by the Commission on Atomic Weights and Isotopic Abundances of the International Union of Pure and Applied Chemistry. This report summarizes reported variations in the isotopic compositions of 20 elements that are due to physical and chemical fractionation processes (not due to radioactive decay) and their effects on the standard atomic-weight uncertainties. For 11 of those elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulfur, chlorine, copper, and selenium), standard atomic-weight uncertainties have been assigned values that are substantially larger than analytical uncertainties because of common isotope-abundance variations in materials of natural terrestrial origin. For 2 elements (chromium and thallium), recently reported isotope-abundance variations potentially are large enough to result in future expansion of their atomic-weight uncertainties. For 7 elements (magnesium, calcium, iron, zinc, molybdenum, palladium, and tellurium), documented isotope variations in materials of natural terrestrial origin are too small to have a significant effect on their standard atomic-weight uncertainties. This compilation indicates the extent to which the atomic weight of an element in a given material may differ from the standard atomic weight of the element. For most elements given above, data are graphically illustrated by a diagram in which the materials are specified in the ordinate and the compositional ranges are plotted along the abscissa in scales of (1) atomic weight, (2) mole fraction of a selected isotope, and (3) delta value of a selected isotope ratio.

PLUTONIUM AND ITS METALLURGY. A STAGE IN ITS DEVELOPMENT: THE INTERNATIONAL CONFERENCE ON THE METALLURGY OF PLUTONIUM (GRENOBLE, APRIL 1960) (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grison, E.

1961-01-01

A discussion is given on physical properties of plutonium, allotropic variations; kinetics of transformation; electrica; and magnetic properties; and electronic structure of the external layers of the atom. Plutonium can be used only as nuclear fuel; it is very expensive and toxic. (auth)

SEPARATION OF PLUTONIUM FROM FISSION PRODUCTS BY A COLLOID REMOVAL PROCESS

DOEpatents

Schubert, J.

1960-05-24

A method is given for separating plutonium from uranium fission products. An acidic aqueous solution containing plutonium and uranium fission products is subjected to a process for separating ionic values from colloidal matter suspended therein while the pH of the solution is maintained between 0 and 4. Certain of the fission products, and in particular, zirconium, niobium, lanthanum, and barium are in a colloidal state within this pH range, while plutonium remains in an ionic form, Dialysis, ultracontrifugation, and ultrafiltration are suitable methods of separating plutonium ions from the colloids.

SEPARATION OF PLUTONIUM VALUES FROM URANIUM AND FISSION PRODUCT VALUES

DOEpatents

Maddock, A.G.; Booth, A.H.

1960-09-13

Separation of plutonium present in small amounts from neutron irradiated uranium by making use of the phenomenon of chemisorption is described. Plutonium in the tetravalent state is chemically absorbed on a fluoride in solid form. The steps for the separation comprise dissolving the irradiated uranium in nitric acid, oxidizing the plutonium in the resulting solution to the hexavalent state, adding to the solution a soluble calcium salt which by the common ion effect inhibits dissolution of the fluoride by the solution, passing the solution through a bed or column of subdivided calcium fluoride which has been sintered to about 8OO deg C to remove the chemisorbable fission products, reducing the plutonium in the solution thus obtained to the tetravalent state, and again passing the solution through a similar bed or column of calcium fluoride to selectively absorb the plutonium, which may then be recovered by treating the calcium fluoride with a solution of ammonium oxalate.

14. END VIEW OF THE PLUTONIUM STORAGE VAULT FROM THE ...

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

14. END VIEW OF THE PLUTONIUM STORAGE VAULT FROM THE REMOTE CONTROL STATION. THE STACKER-RETRIEVER, A REMOTELY-OPERATED, MECHANIZED TRANSPORT SYSTEM, RETRIEVES CONTAINERS OF PLUTONIUM FROM SAFE GEOMETRY PALLETS STORED ALONG THE LENGTH OF THE VAULT. THE STACKER-RETRIEVER RUNS ALONG THE AISLE BETWEEN THE PALLETS OF THE STORAGE CHAMBER. (3/2/86) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

Zinc pharmacokinetic parameters in the determination of body zinc status in children.

PubMed

Vale, S H L; Leite, L D; Alves, C X; Dantas, M M G; Costa, J B S; Marchini, J S; França, M C; Brandão-Neto, J

2014-02-01

Serum or tissue zinc concentrations are often used to assess body zinc status. However, all of these methods are relatively inaccurate. Thus, we investigated three different kinetic methods for the determination of zinc clearance to establish which of these could detect small changes in the body zinc status of children. Forty apparently healthy children were studied. Renal handling of zinc was investigated during intravenous zinc administration (0.06537 mg Zn/kg of body weight), both before and after oral zinc supplementation (5 mg Zn/day for 3 months). Three kinetic methods were used to determine zinc clearance: CZn-Formula A and CZn-Formula B were both used to calculate systemic clearance; the first is a general formula and the second is used for the specific analysis of a single-compartment model; CZn-Formula C is widely used in medical practices to analyze kinetic routine. Basal serum zinc values, which were within the reference range for healthy children, increased significantly after oral zinc supplementation. The three formulas used gave different results for zinc clearance both before and after oral zinc supplementation. CZn-Formula B showed a positive correlation with basal serum zinc concentration after oral supplementation (R2=0.1172, P=0.0306). In addition, CZn-Formula B (P=0.0002) was more effective than CZn-Formula A (P=0.6028) and CZn-Formula C (P=0.0732) in detecting small variations in body zinc status. All three of the formulas used are suitable for studying zinc kinetics; however, CZn-Formula B is particularly effective at detecting small changes in body zinc status in healthy children.

Morphology control of zinc regeneration for zinc-air fuel cell and battery

NASA Astrophysics Data System (ADS)

Wang, Keliang; Pei, Pucheng; Ma, Ze; Xu, Huachi; Li, Pengcheng; Wang, Xizhong

2014-12-01

Morphology control is crucial both for zinc-air batteries and for zinc-air fuel cells during zinc regeneration. Zinc dendrite should be avoided in zinc-air batteries and zinc pellets are yearned to be formed for zinc-air fuel cells. This paper is mainly to analyze the mechanism of shape change and to control the zinc morphology during charge. A numerical three-dimensional model for zinc regeneration is established with COMSOL software on the basis of ionic transport theory and electrode reaction electrochemistry, and some experiments of zinc regeneration are carried out. The deposition process is qualitatively analyzed by the kinetics Monte Carlo method to study the morphological change from the electrocrystallization point of view. Morphological evolution of deposited zinc under different conditions of direct currents and pulse currents is also investigated by simulation. The simulation shows that parametric variables of the flowing electrolyte, the surface roughness and the structure of the electrode, the charging current and mode affect morphological evolution. The uniform morphology of deposited zinc is attained at low current, pulsating current or hydrodynamic electrolyte, and granular morphology is obtained by means of an electrode of discrete columnar structure in combination with high current and flowing electrolyte.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

ULLAH, M K

2001-02-26

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 stablemore » 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.« less

Zinc and Autophagy

PubMed Central

Liuzzi, Juan P.; Guo, Liang; Yoo, Changwon; Stewart, Tiffanie S

2014-01-01

Autophagy is a highly conserved degradative process through which cells overcome stressful conditions. Inasmuch as faulty autophagy has been associated with aging, neuronal degeneration disorders, diabetes, and fatty liver, autophagy is regarded as a potential therapeutic target. This review summarizes the present state of knowledge concerning the role of zinc in the regulation of autophagy, the role of autophagy in zinc metabolism, and the potential role of autophagy as a mediator of the protective effects of zinc. Data from in vitro studies consistently support the notion that zinc is critical for early and late autophagy. Studies have shown inhibition of early and late autophagy in cells cultured in medium treated with zinc chelators. Conversely, excess zinc added to the medium has shown to potentiate the stimulation of autophagy by tamoxifen, H2O2, ethanol and dopamine. The potential role of autophagy in zinc homeostasis has just begun to be investigated.Increasing evidence indicates that autophagy dysregulation causes significant changes in cellular zinc homeostasis. Autophagy may mediate the protective effect of zinc against lipid accumulation, apoptosis and inflammation by promoting degradation of lipid droplets, inflammasomes, p62/SQSTM1 and damaged mitochondria.Studies with humans and animal models are necessary to determine whether autophagy is influenced by zinc intake. PMID:25012760

A dynamic model for predicting growth in zinc-deficient stunted infants given supplemental zinc.

PubMed

Wastney, Meryl E; McDonald, Christine M; King, Janet C

2018-05-01

Zinc deficiency limits infant growth and increases susceptibility to infections, which further compromises growth. Zinc supplementation improves the growth of zinc-deficient stunted infants, but the amount, frequency, and duration of zinc supplementation required to restore growth in an individual child is unknown. A dynamic model of zinc metabolism that predicts changes in weight and length of zinc-deficient, stunted infants with dietary zinc would be useful to define effective zinc supplementation regimens. The aims of this study were to develop a dynamic model for zinc metabolism in stunted, zinc-deficient infants and to use that model to predict the growth response when those infants are given zinc supplements. A model of zinc metabolism was developed using data on zinc kinetics, tissue zinc, and growth requirements for healthy 9-mo-old infants. The kinetic model was converted to a dynamic model by replacing the rate constants for zinc absorption and excretion with functions for these processes that change with zinc intake. Predictions of the dynamic model, parameterized for zinc-deficient, stunted infants, were compared with the results of 5 published zinc intervention trials. The model was then used to predict the results for zinc supplementation regimes that varied in the amount, frequency, and duration of zinc dosing. Model predictions agreed with published changes in plasma zinc after zinc supplementation. Predictions of weight and length agreed with 2 studies, but overpredicted values from a third study in which other nutrient deficiencies may have been growth limiting; the model predicted that zinc absorption was impaired in that study. The model suggests that frequent, smaller doses (5-10 mg Zn/d) are more effective for increasing growth in stunted, zinc-deficient 9-mo-old infants than are larger, less-frequent doses. The dose amount affects the duration of dosing necessary to restore and maintain plasma zinc concentration and growth.

Sources of Radioactive Isotopes for Dirty Bombs

NASA Astrophysics Data System (ADS)

Lubenau, Joel

2004-05-01

From the security perspective, radioisotopes and radioactive sources are not created equal. Of the many radioisotopes used in industrial applications, medical treatments, and scientific research, only eight, when present in relatively large amounts in radioactive sources, pose high security risks primarily because of their prevalence and physical properties. These isotopes are americium-241, californium-252, cesium-137, cobalt-60, iridium-192, radium-226, plutonium-238, and strontium-90. Except for the naturally occurring radium-226, nuclear reactors produce the other seven in bulk commercial quantities. Half of these isotopes emit alpha radiation and would, thus, primarily pose internal threats to health; the others are mainly high-energy gamma emitters and would present both external and internal health hazards. Therefore, the response to a "dirty bomb" event depends on what type of radioisotope is chosen and how it is employed. While only a handful of major corporations produce the reactor-generated radioisotopes, they market these materials to thousands of smaller companies and users throughout the world. Improving the security of the high-risk radioactive sources will require, among other efforts, cooperation among source suppliers and regulatory agencies.

10 CFR 71.88 - Air transport of plutonium.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 2 2012-01-01 2012-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any..., whether for import, export, or domestic shipment, is not transported by air or delivered to a carrier for...

10 CFR 71.88 - Air transport of plutonium.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 2 2014-01-01 2014-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any..., whether for import, export, or domestic shipment, is not transported by air or delivered to a carrier for...

10 CFR 71.88 - Air transport of plutonium.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 2 2013-01-01 2013-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any..., whether for import, export, or domestic shipment, is not transported by air or delivered to a carrier for...

10 CFR 71.88 - Air transport of plutonium.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any..., whether for import, export, or domestic shipment, is not transported by air or delivered to a carrier for...

10 CFR 71.88 - Air transport of plutonium.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any..., whether for import, export, or domestic shipment, is not transported by air or delivered to a carrier for...

In search of plutonium: A nonproliferation journey

NASA Astrophysics Data System (ADS)

Hecker, Siegfried

2010-02-01

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. )

Heterogeneous distribution of Zn stable isotopes in mice and applications to medical sciences

NASA Astrophysics Data System (ADS)

Moynier, F.; Fujii, T.; Shaw, A.; Le Borgne, M.

2013-12-01

Zinc is required for the function of more than 300 enzymes involved in many metabolic pathways, and is a vital micronutrient for living organisms. To investigate if Zn isotopes could be used to better understand metal homeostasis, as well as a biomarker for diseases, we assessed the distribution of natural Zn isotopes in various mouse tissues. We found that, with respect to Zn isotopes, most mouse organs are isotopically distinct and that the total range of variation within one mouse encompasses the variations observed in the Earth's crust. Therefore, biological activity must have a major impact on the distribution of Zn isotopes in inorganic materials. The most striking aspect of the data is that red blood cells and bones are enriched by ~0.5 per mil in 66Zn relative to 64Zn when compared to serum, and up to ~1 per mil when compared to the brain and liver. This fractionation is well explained by the equilibrium distribution of isotopes between different bonding environments of Zn in different organs. Differences in gender and genetic background did not appear to affect the isotopic distribution of Zn. Together, these results suggest that potential use of Zn isotopes as a tracer for dietary Zn, and for detecting disturbances in Zn metabolism due to pathological conditions.

Transport of plutonium in snowmelt run-off

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purtymun, W.D.; Peters, R.; Maes, M.N.

1990-07-01

Plutonium in treated low-level radioactive effluents released into intermittent streams is bound by ion exchange or adsorption to bed sediments in the stream channel. These sediments are subject to transport with summer and spring snowmelt run-off. A study was made of the transport of plutonium during seven spring run-off events in Los Alamos and Pueblo canyons from the Laboratory boundary to Otowi on the Rio Grande. The melting of the snowpack during these years resulted in run-off that was large enough to reach the eastern edge of the Laboratory. Of these seven run-off events recorded at the Laboratory boundary, onlymore » five had sufficient flow to reach the Rio Grande. The volume of the five events that reached the river ranged from 5 {times} 10{sup 3} m{sup 3} to 104 {times} 10{sup 3} m{sup 3}. The five run-off events carried 119 {times} 10{sup 3} kg of suspended sediments and 1073 {times} 10{sup 3} kg of bed sediments, and transported 598 {mu}Ci of plutonium to the river. Of the 598 {mu}Ci of plutonium, 3% was transported in solution, 57% with suspended sediments, and 40% with bed sediments. 13 refs., 3 figs., 6 tabs.« less

Production of zinc pellets

DOEpatents

Cooper, J.F.

1996-11-26

Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

Production of zinc pellets

DOEpatents

Cooper, John F.

1996-01-01

Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries.

25. Plutonium Recovery From Contaminated Materials, Architectural Plans & Details, ...

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

25. Plutonium Recovery From Contaminated Materials, Architectural Plans & Details, Building 232-Z, U.S. Atomic Energy Commission, Hanford Atomic Products Operation, General Electric Company, Dwg. No. H-2-23105, 1959. - Plutonium Finishing Plant, Waste Incinerator Facility, 200 West Area, Richland, Benton County, WA

Zinc Signals and Immunity.

PubMed

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-10-24

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as "zinc waves", and late homeostatic zinc signals regarding prolonged changes in intracellular zinc.

Zinc Signals and Immunity

PubMed Central

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-01-01

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as “zinc waves”, and late homeostatic zinc signals regarding prolonged changes in intracellular zinc. PMID:29064429

Zinc in Cellular Regulation: The Nature and Significance of "Zinc Signals".

PubMed

Maret, Wolfgang

2017-10-31

In the last decade, we witnessed discoveries that established Zn 2+ as a second major signalling metal ion in the transmission of information within cells and in communication between cells. Together with Ca 2+ and Mg 2+ , Zn 2+ covers biological regulation with redox-inert metal ions over many orders of magnitude in concentrations. The regulatory functions of zinc ions, together with their functions as a cofactor in about three thousand zinc metalloproteins, impact virtually all aspects of cell biology. This article attempts to define the regulatory functions of zinc ions, and focuses on the nature of zinc signals and zinc signalling in pathways where zinc ions are either extracellular stimuli or intracellular messengers. These pathways interact with Ca 2+ , redox, and phosphorylation signalling. The regulatory functions of zinc require a complex system of precise homeostatic control for transients, subcellular distribution and traffic, organellar homeostasis, and vesicular storage and exocytosis of zinc ions.

Radiological analysis of plutonium glass batches with natural/enriched boron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rainisch, R.

2000-06-22

The disposition of surplus plutonium inventories by the US Department of Energy (DOE) includes the immobilization of certain plutonium materials in a borosilicate glass matrix, also referred to as vitrification. This paper addresses source terms of plutonium masses immobilized in a borosilicate glass matrix where the glass components include both natural boron and enriched boron. The calculated source terms pertain to neutron and gamma source strength (particles per second), and source spectrum changes. The calculated source terms corresponding to natural boron and enriched boron are compared to determine the benefits (decrease in radiation source terms) for to the use ofmore » enriched boron. The analysis of plutonium glass source terms shows that a large component of the neutron source terms is due to (a, n) reactions. The Americium-241 and plutonium present in the glass emit alpha particles (a). These alpha particles interact with low-Z nuclides like B-11, B-10, and O-17 in the glass to produce neutrons. The low-Z nuclides are referred to as target particles. The reference glass contains 9.4 wt percent B{sub 2}O{sub 3}. Boron-11 was found to strongly support the (a, n) reactions in the glass matrix. B-11 has a natural abundance of over 80 percent. The (a, n) reaction rates for B-10 are lower than for B-11 and the analysis shows that the plutonium glass neutron source terms can be reduced by artificially enriching natural boron with B-10. The natural abundance of B-10 is 19.9 percent. Boron enriched to 96-wt percent B-10 or above can be obtained commercially. Since lower source terms imply lower dose rates to radiation workers handling the plutonium glass materials, it is important to know the achievable decrease in source terms as a result of boron enrichment. Plutonium materials are normally handled in glove boxes with shielded glass windows and the work entails both extremity and whole-body exposures. Lowering the source terms of the plutonium batches will

QUANTITATIVE PLUTONIUM MICRODISTRIBUTION IN BONE TISSUE OF VERTEBRA FROM A MAYAK WORKER

PubMed Central

Lyovkina, Yekaterina V.; Miller, Scott C.; Romanov, Sergey A.; Krahenbuhl, Melinda P.; Belosokhov, Maxim V.

2010-01-01

The purpose was to obtain quantitative data on plutonium microdistribution in different structural elements of human bone tissue for local dose assessment and dosimetric models validation. A sample of the thoracic vertebra was obtained from a former Mayak worker with a rather high plutonium burden. Additional information was obtained on occupational and exposure history, medical history, and measured plutonium content in organs. Plutonium was detected in bone sections from its fission tracks in polycarbonate film using neutron-induced autoradiography. Quantitative analysis of randomly selected microscopic fields on one of the autoradiographs was performed. Data included fission fragment tracks in different bone tissue and surface areas. Quantitative information on plutonium microdistribution in human bone tissue was obtained for the first time. From these data, quantitative relationship of plutonium decays in bone volume to decays on bone surface in cortical and trabecular fractions were defined as 2.0 and 0.4, correspondingly. The measured quantitative relationship of decays in bone volume to decays on bone surface does not coincide with recommended models for the cortical bone fraction by the International Commission on Radiological Protection. Biokinetic model parameters of extrapulmonary compartments might need to be adjusted after expansion of the data set on quantitative plutonium microdistribution in other bone types in human as well as other cases with different exposure patterns and types of plutonium. PMID:20838087

Zinc and Wound Healing: A Review of Zinc Physiology and Clinical Applications.

PubMed

Kogan, Samuel; Sood, Aditya; Garnick, Mark S

2017-04-01

Our understanding of the role of zinc in normal human physiology is constantly expanding, yet there are major gaps in our knowledge with regard to the function of zinc in wound healing. This review aims to provide the clinician with sufficient understanding of zinc biology and an up-to-date perspective on the role of zinc in wound healing. Zinc is an essential ion that is crucial for maintenance of normal physiology, and zinc deficiency has many manifestations ranging from delayed wound healing to immune dysfunction and impairment of multiple sensory systems. While consensus has been reached regarding the detrimental effects of zinc deficiency on wound healing, there is considerable discord in the literature on the optimal methods and true benefits of zinc supplementation.

Zinc

MedlinePlus

... Guidelines for Americans and the U.S. Department of Agriculture's MyPlate . Where can I find out more about ... on food sources of zinc: U.S. Department of Agriculture's (USDA’s) National Nutrient Database Nutrient List for zinc ( ...

26. Plutonium Recovery From Contaminated Materials, Architectural Elevations, Sections & ...

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

26. Plutonium Recovery From Contaminated Materials, Architectural Elevations, Sections & Dets., Building 232-Z, U.S. Atomic Energy Commission, Hanford Atomic Products Operation, General Electric Company, Dwg. No. H-2-23106, 1959. - Plutonium Finishing Plant, Waste Incinerator Facility, 200 West Area, Richland, Benton County, WA

PLUTONIUM METALLIC FUELS FOR FAST REACTORS

DOE Office of Scientific and Technical Information (OSTI.GOV)

STAN, MARIUS; HECKER, SIEGFRIED S.

2007-02-07

Early interest in metallic plutonium fuels for fast reactors led to much research on plutonium alloy systems including binary solid solutions with the addition of aluminum, gallium, or zirconium and low-melting eutectic alloys with iron and nickel or cobalt. There was also interest in ternaries of these elements with plutonium and cerium. The solid solution and eutectic alloys have most unusual properties, including negative thermal expansion in some solid-solution alloys and the highest viscosity known for liquid metals in the Pu-Fe system. Although metallic fuels have many potential advantages over ceramic fuels, the early attempts were unsuccessful because these fuelsmore » suffered from high swelling rates during burn up and high smearing densities. The liquid metal fuels experienced excessive corrosion. Subsequent work on higher-melting U-PuZr metallic fuels was much more promising. In light of the recent rebirth of interest in fast reactors, we review some of the key properties of the early fuels and discuss the challenges presented by the ternary alloys.« less

A Plutonium-Contaminated Wound, 1985, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doran M. Christensen, DO, REAC /TS Associate Director and Staff Physician Eugene H. Carbaugh, CHP, Staff Scientist, Internal Dosimetry Manager, Pacific Northwest National Laboratory, Richland, Washington

2012-02-02

A hand injury occurred at a U.S. facility in 1985 involving a pointed shaft (similar to a meat thermometer) that a worker was using to remove scrap solid plutonium from a plastic bottle. The worker punctured his right index finger on the palm side at the metacarpal-phalangeal joint. The wound was not through-and- through, although it was deep. The puncture wound resulted in deposition of ~48 kBq of alpha activity from the weapons-grade plutonium mixture with a nominal 12 to 1 Pu-alpha to {sup 241}Am-alpha ratio. This case clearly showed that DTPA was very effective for decorporation of plutonium andmore » americium. The case is a model for management of wounds contaminated with transuranics: (1) a team approach for dealing with all of the issues surrounding the incident, including the psychological, (2) early surgical intervention for foreign-body removal, (3) wound irrigation with DTPA solution, and (4) early and prolonged DTPA administration based upon bioassay and in vivo dosimetry.« less

Advances in containment methods and plutonium recovery strategies that led to the structural characterization of plutonium(IV) tetrachloride tris-diphenylsulfoxide, PuCl 4(OSPh 2) 3

DOE PAGES

Schrell, Samantha K.; Boland, Kevin Sean; Cross, Justin Neil; ...

2017-01-18

In an attempt to further advance the understanding of plutonium coordination chemistry, we report a robust method for recycling and obtaining plutonium aqueous stock solutions that can be used as a convenient starting material in plutonium synthesis. This approach was used to prepare and characterize plutonium(IV) tetrachloride tris-diphenylsulfoxide, PuCl 4(OSPh 2) 3, by single crystal X-ray diffraction. The PuCl 4(OSPh 2) 3 compound represents a rare example of a 7-coordinate plutonium(IV) complex. Structural characterization of PuCl 4(OSPh 2) 3 by X-ray diffraction utilized a new containment method for radioactive crystals. The procedure makes use of epoxy, polyimide loops, and amore » polyester sheath to provide a robust method for safely containing and easily handling radioactive samples. Lastly, the described procedure is more user friendly than traditional containment methods that employ fragile quartz capillary tubes. Additionally, moving to polyester, instead of quartz, lowers the background scattering from the heavier silicon atoms.« less

Hyperaccumulation of zinc by zinc-depleted Candida utilis grown in chemostat culture.

PubMed

Lawford, H G; Pik, J R; Lawford, G R; Williams, T; Kligerman, A

1980-01-01

The steady-state levels of zinc in Candida utilis yeast grown in continuous culture under conditions of zinc limitations are <1nmol Zn2+/mg dry weight of cells. Unlike carbon-limited cells, zinc-depleted cells from a zinc-limited chemostat possess the capacity to accumulate and store zinc at levels far in excess of the steady-state level of 4 nmol/mg dry biomass observed in carbon-limited chemostat cultures. Zinc uptake is energy-dependent and apparently undirectional since accumulated 65Zn neither exists from preloaded cells nor exchanges with cold Zn2+. The transport system exhibits a high affinity for Zn2+ (Km =.36micrM) with a Vmaxof 2.2 nmol per minute per milligram dry weight of cells. Growth during the period of the uptake assay is responsible for the apparent plateau level of 35 nmol Zn2+/mg dry weight of cells achieved after 20-30 min in the presence of 65Zn at pH 4.5 and 30 degrees C. Inhibition of growth during the uptake assay by cycloheximide results in a biphasic linear pattern of zinc accumulation where the cellular zinc is about 60 nmol/mg dry weight after 1 h. The enhanced level of accumulated zinc is not inhibtory to growth. Zinc-depleted C. utilis contains elevated amounts of polyphosphate and this anionic evidence does not allow discrimination between possible regulation of zinc homestasis either by inhibitions of zinc efflux through control of the membrane carrier or by control of the synthesis of a cytoplasmic zinc-sequestering macromolecule.

CARBONATE METHOD OF SEPARATION OF TETRAVALENT PLUTONIUM FROM FISSION PRODUCT VALUES

DOEpatents

Duffield, R.B.; Stoughton, R.W.

1959-02-01

It has been found that plutonium forms an insoluble precipitate with carbonate ion when the carbonate ion is present in stoichiometric proportions, while an excess of the carbonate ion complexes plutonium and renders it soluble. A method for separating tetravalent plutonium from lanthanum-group rare earths has been based on this discovery, since these rare earths form insoluble carbonates in approximately neutral solutions. According to the process the pH is adjusted to between 5 and 7, and approximately stoichiometric amounts of carbonate ion are added to the solution causing the formation of a precipitate of plutonium carbonate and the lanthanum-group rare earth carbonates. The precipitate is then separated from the solution and contacted with a carbonate solution of a concentration between 1 M and 3 M to complex and redissolve the plutonium precipitate, and thus separate it from the insoluble rare earth precipitate.

PRECIPITATION METHOD OF SEPARATING PLUTONIUM FROM CONTAMINATING ELEMENTS

DOEpatents

Duffield, R.B.

1959-02-24

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

Density of Plutonium Turnings Generated from Machining Activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonzales, John Robert; Vigil, Duane M.; Jachimowski, Thomas A.

The purpose of this project was to determine the density of plutonium (Pu) turnings generated from the range of machining activities, using both surrogate material and machined Pu turnings. Verify that 500 grams (g) of plutonium will fit in a one quart container using a surrogate equivalent volume and that 100 grams of Pu will fit in a one quart Savy container.

Gaseous species as reaction tracers in the solvothermal synthesis of the zinc oxide terephthalate MOF-5.

PubMed

Hausdorf, Steffen; Baitalow, Felix; Seidel, Jürgen; Mertens, Florian O R L

2007-05-24

Gaseous species emitted during the zinc oxide/zinc hydroxide 1,4-benzenedicarboxylate metal organic framework synthesis (MOF-5, MOF-69c) have been used to investigate the reaction scheme that leads to the framework creation. Changes of the gas-phase composition over time indicate that the decomposition of the solvent diethylformamide occurs at least via two competing reaction pathways that can be linked to the reaction's overall water and pH management. From isotope exchange experiments, we deduce that one of the decomposition pathways leads to the removal of water from the reaction mixture, which sets the conditions when the synthesis of an oxide-based (MOF-5) instead of an hydroxide-based MOF (MOF-69c) occurs. A quantitative account of most reactants and byproducts before and after the MOF-5/MOF-69c synthesis is presented. From the investigation of the reaction intermediates and byproducts, we derive a proposal of a basic reaction scheme for the standard synthesis zinc oxide carboxylate MOFs.

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

DOEpatents

Faris, B.F.

1961-04-25

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

Update on zinc biology.

PubMed

Solomons, Noel W

2013-01-01

Zinc has become a prominent nutrient of clinical and public health interest in the new millennium. Functions and actions for zinc emerge as increasingly ubiquitous in mammalian anatomy, physiology and metabolism. There is undoubtedly an underpinning in fundamental biology for all of the aspects of zinc in human health (clinical and epidemiological) in pediatric and public health practice. Unfortunately, basic science research may not have achieved a full understanding as yet. As a complement to the applied themes in the companion articles, a selection of recent advances in the domains homeostatic regulation and transport of zinc is presented; they are integrated, in turn, with findings on genetic expression, intracellular signaling, immunity and host defense, and bone growth. The elements include ionic zinc, zinc transporters, metallothioneins, zinc metalloenzymes and zinc finger proteins. In emerging basic research, we find some plausible mechanistic explanations for delayed linear growth with zinc deficiency and increased infectious disease resistance with zinc supplementation. Copyright © 2013 S. Karger AG, Basel.

High-Temperature Oxidation of Plutonium Surrogate Metals and Alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sparks, Joshua C.; Krantz, Kelsie E.; Christian, Jonathan H.

The Plutonium Management and Disposition Agreement (PMDA) is a nuclear non-proliferation agreement designed to remove 34 tons of weapons-grade plutonium from Russia and the United States. While several removal options have been proposed since the agreement was first signed in 2000, processing the weapons-grade plutonium to mixed-oxide (MOX) fuel has remained the leading candidate for achieving the goals of the PMDA. However, the MOX program has received its share of criticisms, which causes its future to be uncertain. One alternative pathway for plutonium disposition would involve oxidizing the metal followed by impurity down blending and burial in the Waste Isolationmore » Pilot Plant (WIPP) in Carlsbad, New Mexico. This pathway was investigated by use of a hybrid microwave and a muffle furnace with Fe and Al as surrogate materials. Oxidation occurred similarly in the microwave and muffle furnace; however, the microwave process time was significantly faster.« less

Zinc at glutamatergic synapses.

PubMed

Paoletti, P; Vergnano, A M; Barbour, B; Casado, M

2009-01-12

It has long been known that the mammalian forebrain contains a subset of glutamatergic neurons that sequester zinc in their synaptic vesicles. This zinc may be released into the synaptic cleft upon neuronal activity. Extracellular zinc has the potential to interact with and modulate many different synaptic targets, including glutamate receptors and transporters. Among these targets, NMDA receptors appear particularly interesting because certain NMDA receptor subtypes (those containing the NR2A subunit) contain allosteric sites exquisitely sensitive to extracellular zinc. The existence of these high-affinity zinc binding sites raises the possibility that zinc may act both in a phasic and tonic mode. Changes in zinc concentration and subcellular zinc distribution have also been described in several pathological conditions linked to glutamatergic transmission dysfunctions. However, despite intense investigation, the functional significance of vesicular zinc remains largely a mystery. In this review, we present the anatomy and the physiology of the glutamatergic zinc-containing synapse. Particular emphasis is put on the molecular and cellular mechanisms underlying the putative roles of zinc as a messenger involved in excitatory synaptic transmission and plasticity. We also highlight the many controversial issues and unanswered questions. Finally, we present and compare two widely used zinc chelators, CaEDTA and tricine, and show why tricine should be preferred to CaEDTA when studying fast transient zinc elevations as may occur during synaptic activity.

MCNP Parametric Studies of Plutonium Metal and Various Interstitial Moderating Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glazener, Natasha; Kamm, Ryan James

2017-03-31

Nuclear Criticality Safety (NCS) has performed calculations evaluating the effect of different interstitial materials on 5.0-kg of plutonium metal. As with all non-fissionable interstitials, the results here illustrate that it requires significant quantities of oil to be intimately mixed with plutonium, reflected by a thick layer of full-density water, to achieve the same reactivity as that of solid plutonium metal.

METHOD OF FORMING PLUTONIUM-BEARING CARRIER PRECIPITATES AND WASHING SAME

DOEpatents

Faris, B.F.

1959-02-24

An improvement of the lanthanum fluoride carrier precipitation process for the recovery of plutonium is presented. In this process the plutonium is first segregated in the LaF/su precipitate and this precipitate is later dissolved and the plutonium reprecipitated as the peroxide. It has been found that the loss of plutonium by its remaining in the supernatant liquid associated with the peroxide precipitate is greatly reduced if, before dissolution, the LaF/ sub 3/ precipitate is subjected to a novel washing step which constitutes the improvement of this patent. The step consists in intimately contactifng the LaF/ sub 3/ precipitate with a 4 to 10 percent solution of sodium hydrogen sulfate at a temperature between 10 and 95 deg C for 1/2 to 3 hours.

Gallium isotopic evidence for extensive volatile loss from the Moon during its formation

PubMed Central

Kato, Chizu; Moynier, Frédéric

2017-01-01

The distribution and isotopic composition of volatile elements in planetary materials holds a key to the characterization of the early solar system and the Moon’s formation. The Moon and Earth are chemically and isotopically very similar. However, the Moon is highly depleted in volatile elements and the origin of this depletion is still debated. We present gallium isotopic and elemental measurements in a large set of lunar samples to constrain the origin of this volatile depletion. We show that while Ga has a geochemical behavior different from zinc, both elements show a systematic enrichment in the heavier isotopes in lunar mare basalts and Mg-suite rocks compared to the silicate Earth, pointing to a global-scale depletion event. On the other hand, the ferroan anorthosites are isotopically heterogeneous, suggesting a secondary distribution of Ga at the surface of the Moon by volatilization and condensation. The isotopic difference of Ga between Earth and the Moon and the isotopic heterogeneity of the crustal ferroan anorthosites suggest that the volatile depletion occurred following the giant impact and during the lunar magma ocean phase. These results point toward a Moon that has lost its volatile elements during a whole-scale evaporation event and that is now relatively dry compared to Earth. PMID:28782027

Zinc and Zinc Transporters: Novel Regulators of Ventricular Myocardial Development.

PubMed

Lin, Wen; Li, Deqiang

2018-06-01

Ventricular myocardial development is a well-orchestrated process involving different cardiac structures, multiple signal pathways, and myriad proteins. Dysregulation of this important developmental event can result in cardiomyopathies, such as left ventricle non-compaction, which affect the pediatric population and the adults. Human and mouse studies have shed light upon the etiology of some cardiomyopathy cases and highlighted the contribution of both genetic and environmental factors. However, the regulation of ventricular myocardial development remains incompletely understood. Zinc is an essential trace metal with structural, enzymatic, and signaling function. Perturbation of zinc homeostasis has resulted in developmental and physiological defects including cardiomyopathy. In this review, we summarize several mechanisms by which zinc and zinc transporters can impact the regulation of ventricular myocardial development. Based on our review, we propose that zinc deficiency and mutations of zinc transporters may underlie some cardiomyopathy cases especially those involving ventricular myocardial development defects.

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

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

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

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

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

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

Developing a physiologically based approach for modeling plutonium decorporation therapy with DTPA.

PubMed

Kastl, Manuel; Giussani, Augusto; Blanchardon, Eric; Breustedt, Bastian; Fritsch, Paul; Hoeschen, Christoph; Lopez, Maria Antonia

2014-11-01

To develop a physiologically based compartmental approach for modeling plutonium decorporation therapy with the chelating agent Diethylenetriaminepentaacetic acid (Ca-DTPA/Zn-DTPA). Model calculations were performed using the software package SAAM II (©The Epsilon Group, Charlottesville, Virginia, USA). The Luciani/Polig compartmental model with age-dependent description of the bone recycling processes was used for the biokinetics of plutonium. The Luciani/Polig model was slightly modified in order to account for the speciation of plutonium in blood and for the different affinities for DTPA of the present chemical species. The introduction of two separate blood compartments, describing low-molecular-weight complexes of plutonium (Pu-LW) and transferrin-bound plutonium (Pu-Tf), respectively, and one additional compartment describing plutonium in the interstitial fluids was performed successfully. The next step of the work is the modeling of the chelation process, coupling the physiologically modified structure with the biokinetic model for DTPA. RESULTS of animal studies performed under controlled conditions will enable to better understand the principles of the involved mechanisms.

Excess plutonium disposition: The deep borehole option

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferguson, K.L.

1994-08-09

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 relatedmore » 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.« less

Determination of plutonium-239, thorium-232, and natural uranium isotopic concentrations in biological samples using photofission track analysis

NASA Astrophysics Data System (ADS)

Parry, James Roswell

Fission track analysis (FTA) has many uses in the scientific community including but not limited to geological dating, neutron flux mapping, and dose reconstruction. The common method of fission for FTA is through neutrons from a nuclear reactor. This dissertation investigates the use of bremsstrahlung radiation produced from an electron linear accelerator to induce fission in FTA samples. This provides a means of simultaneously measuring the amount of Pu-239, U-nat, and Th-232 in a single sample. The benefit of measuring the three isotopes simultaneously is the possible elimination of costly and time consuming chemical processing for dose reconstruction samples. Samples containing the three isotopes were irradiated in two different bremsstrahlung spectra and a neutron spectrum to determine the amount of Pu-239, U-nat, and Th-232 in the samples. The reaction rate from the calibration samples and the counted fission tracks on the samples were used in determining the concentration of each isotope in the samples. The results were accurate to within a factor of two or three, showing that the method can work to predict the concentrations of multiple isotopes in a sample. The limitations of current accelerators and detectors limits the application of this specific procedure to higher concentrations of isotopes. The method detection limits for Pu-239, U-nat, and Th-232 are 20 pCi, 1 fCi, and 0.4 flCI respectively. Analysis of extremely low concentrations of isotopes would require the use of different detectors such as quartz due to the embrittlement encountered in the Lexan at high exposures. Cracking of the Texan detectors started to appear at a fluence of about 2 x 1018 electrons from the accelerator. This may be partly due to the beam stop not being an adequate thickness. The procedure is likely limited to specialty applications for the near term. However, with the world concerns of exposure to depleted uranium, this procedure may find applications in this area since

Development of first ever scanning probe microscopy capabilities for plutonium

NASA Astrophysics Data System (ADS)

Beaux, Miles F.; Cordoba, Miguel Santiago; Zocco, Adam T.; Vodnik, Douglas R.; Ramos, Michael; Richmond, Scott; Moore, David P.; Venhaus, Thomas J.; Joyce, Stephen A.; Usov, Igor O.

2017-04-01

Scanning probe microscopy capabilities have been developed for plutonium and its derivative compounds. Specifically, a scanning tunneling microscope and an atomic force microscope housed in an ultra-high vacuum system and an inert atmosphere glove box, respectively, were prepared for the introduction of small non-dispersible δ-Pu coupons. Experimental details, procedures, and preliminary imaging of δ-Pu coupons are presented to demonstrate the functionality of these new capabilities. These first of a kind capabilities for plutonium represent a significant step forward in the ability to characterize and understand plutonium surfaces with high spatial resolution.

Removal of plutonium and americium from alkaline waste solutions

DOEpatents

Schulz, Wallace W.

1979-01-01

High salt content, alkaline waste solutions containing plutonium and americium are contacted with a sodium titanate compound to effect removal of the plutonium and americium from the alkaline waste solution onto the sodium titanate and provide an effluent having a radiation level of less than 10 nCi per gram alpha emitters.

SEPARATION OF PLUTONIUM IONS FROM SOLUTION BY ADSORPTION ON ZIRCONIUM PYROPHOSPHATE

DOEpatents

Stoughton, R.W.

1961-01-31

A method is given for separating plutonium in its reduced, phosphate- insoluble state from other substances. It involves contacting a solution containing the plutonium with granular zirconium pyrophosphate.

Zinc Biochemistry: From a Single Zinc Enzyme to a Key Element of Life12

PubMed Central

Maret, Wolfgang

2013-01-01

The nutritional essentiality of zinc for the growth of living organisms had been recognized long before zinc biochemistry began with the discovery of zinc in carbonic anhydrase in 1939. Painstaking analytical work then demonstrated the presence of zinc as a catalytic and structural cofactor in a few hundred enzymes. In the 1980s, the field again gained momentum with the new principle of “zinc finger” proteins, in which zinc has structural functions in domains that interact with other biomolecules. Advances in structural biology and a rapid increase in the availability of gene/protein databases now made it possible to predict zinc-binding sites from metal-binding motifs detected in sequences. This procedure resulted in the definition of zinc proteomes and the remarkable estimate that the human genome encodes ∼3000 zinc proteins. More recent developments focus on the regulatory functions of zinc(II) ions in intra- and intercellular information transfer and have tantalizing implications for yet additional functions of zinc in signal transduction and cellular control. At least three dozen proteins homeostatically control the vesicular storage and subcellular distribution of zinc and the concentrations of zinc(II) ions. Novel principles emerge from quantitative investigations on how strongly zinc interacts with proteins and how it is buffered to control the remarkably low cellular and subcellular concentrations of free zinc(II) ions. It is fair to conclude that the impact of zinc for health and disease will be at least as far-reaching as that of iron. PMID:23319127

Submicron hard X-ray fluorescence imaging of synthetic elements.

PubMed

Jensen, Mark P; Aryal, Baikuntha P; Gorman-Lewis, Drew; Paunesku, Tatjana; Lai, Barry; Vogt, Stefan; Woloschak, Gayle E

2012-04-13

Synchrotron-based X-ray fluorescence microscopy (XFM) using hard X-rays focused into sub-micron spots is a powerful technique for elemental quantification and mapping, as well as microspectroscopic measurements such as μ-XANES (X-ray absorption near edge structure). We have used XFM to image and simultaneously quantify the transuranic element plutonium at the L(3) or L(2)-edge as well as Th and lighter biologically essential elements in individual rat pheochromocytoma (PC12) cells after exposure to the long-lived plutonium isotope (242)Pu. Elemental maps demonstrate that plutonium localizes principally in the cytoplasm of the cells and avoids the cell nucleus, which is marked by the highest concentrations of phosphorus and zinc, under the conditions of our experiments. The minimum detection limit under typical acquisition conditions with an incident X-ray energy of 18 keV for an average 202 μm(2) cell is 1.4 fg Pu or 2.9×10(-20) moles Pu μm(-2), which is similar to the detection limit of K-edge XFM of transition metals at 10 keV. Copper electron microscopy grids were used to avoid interference from gold X-ray emissions, but traces of strontium present in naturally occurring calcium can still interfere with plutonium detection using its L(α) X-ray emission. Copyright © 2012 Elsevier B.V. All rights reserved.

Tracing of Zinc Nanocrystals in the Anterior Pituitary of Zinc-Deficient Wistar Rats.

PubMed

Kuldeep, Anjana; Nair, Neena; Bedwal, Ranveer Singh

2017-06-01

The aim of this study was to trace zinc nanocrystals in the anterior pituitary of zinc-deficient Wistar rats by using autometallographic technique. Male Wistar rats (30-40 days of age, pre-pubertal period) of 40-50 g body weight were divided into the following: the ZC (zinc control) group-fed with 100 ppm zinc in diet, the ZD (zinc-deficient) group-fed with zinc-deficient (1.00 ppm) diet and the PF (pair-fed) group-received 100 ppm zinc in diet. The experiments were set for 2 and 4 weeks. Pituitary was removed and processed for the autometallographic technique. The control and pair-fed groups retained their normal morphological features. However, male Wistar rats fed on zinc-deficient diet for 2 and 4 weeks displayed a wide range of symptoms such as significant (P < 0.05) decrease in diet consumption, body weight and pituitary weight and decrease in gradation of intensity of zinc nanocrystals in the nuclei. The present findings suggest that the dietary zinc deficiency causes decreased intensity of zinc nanocrystals localization and their distribution in the pituitary thereby contributing to the dysfunction of the pituitary of the male Wistar rats. The severity of zinc deficiency symptoms progressed after the second week of the experiment. Decreased intensity of zinc nanocrystals attenuates the pituitary function which would exert its affect on other endocrine organs impairing their functions indicating that the metabolic regulation of pituitary is mediated to a certain extent by zinc and/or hypothalamus-hypophysial system which also reflects its essentiality during the period of growth.

Plutonium immobilization in glass and ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knecht, D.A.; Murphy, W.M.

1996-05-01

The Materials Research Society Nineteenth Annual Symposium on the Scientific Basis for Nuclear Waste Management was held in Boston on November 27 to December 1, 1995. Over 150 papers were presented at the Symposium dealing with all aspects of nuclear waste management and disposal. Fourteen oral sessions and on poster session included a Plenary session on surplus plutonium dispositioning and waste forms. The proceedings, to be published in April, 1996, will provide a highly respected, referred compilation of the state of scientific development in the field of nuclear waste management. This paper provides a brief overview of the selected Symposiummore » papers that are applicable to plutonium immobilization and plutonium waste form performance. Waste forms that were described at the Symposium cover most of the candidate Pu immobilization options under consideration, including borosilicate glass with a melting temperature of 1150 {degrees}C, a higher temperature (1450 {degrees}C) lanthanide glass, single phase ceramics, multi-phase ceramics, and multi-phase crystal-glass composites (glass-ceramics or slags). These Symposium papers selected for this overview provide the current status of the technology in these areas and give references to the relevant literature.« less

METHOD FOR DISSOLVING LANTHANUM FLUORIDE CARRIER FOR PLUTONIUM

DOEpatents

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

1961-08-01

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

Contribution of Zinc Solubilizing Bacteria in Growth Promotion and Zinc Content of Wheat.

PubMed

Kamran, Sana; Shahid, Izzah; Baig, Deeba N; Rizwan, Muhammad; Malik, Kauser A; Mehnaz, Samina

2017-01-01

Zinc is an imperative micronutrient required for optimum plant growth. Zinc solubilizing bacteria are potential alternatives for zinc supplementation and convert applied inorganic zinc to available forms. This study was conducted to screen zinc solubilizing rhizobacteria isolated from wheat and sugarcane, and to analyze their effect on wheat growth and development. Fourteen exo-polysaccharides producing bacterial isolates of wheat were identified and characterized biochemically as well as on the basis of 16S rRNA gene sequences. Along these, 10 identified sugarcane isolates were also screened for zinc solubilizing ability on five different insoluble zinc sources. Out of 24, five strains, i.e., EPS 1 ( Pseudomonas fragi) , EPS 6 ( Pantoea dispersa) , EPS 13 ( Pantoea agglomerans) , PBS 2 ( E. cloacae) and LHRW1 ( Rhizobium sp.) were selected (based on their zinc solubilizing and PGP activities) for pot scale plant experiments. ZnCO 3 was used as zinc source and wheat seedlings were inoculated with these five strains, individually, to assess their effect on plant growth and development. The effect on plants was analyzed based on growth parameters and quantifying zinc content of shoot, root and grains using atomic absorption spectroscopy. Plant experiment was performed in two sets. For first set of plant experiments (harvested after 1 month), maximum shoot and root dry weights and shoot lengths were noted for the plants inoculated with Rhizobium sp. (LHRW1) while E. cloacae (PBS 2) increased both shoot and root lengths. Highest zinc content was found in shoots of E. cloacae (PBS 2) and in roots of P. agglomerans (EPS 13) followed by zinc supplemented control. For second set of plant experiment, when plants were harvested after three months, Pantoea dispersa (EPS 6), P. agglomerans (EPS 13) and E. cloacae (PBS 2) significantly increased shoot dry weights. However, significant increase in root dry weights and maximum zinc content was recorded for Pseudomonas fragi (EPS

Crystalline matrices for the immobilization of plutonium and actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, E.B.; Burakov, E.E.; Galkin, Ya.B.

1996-05-01

The management of weapon plutonium, disengaged as a result of conversion, is considered together with the problem of the actinide fraction of long-lived high level radioactive wastes. It is proposed to use polymineral ceramics based on crystalline host-phases: zircon ZrSiO{sub 4} and zirconium dioxide ZrO{sub 2}, for various variants of the management of plutonium and actinides (including the purposes of long-term safe storage or final disposal from the human activity sphere). It is shown that plutonium and actinides are able to form with these phases on ZrSiO{sub 4} and ZrO{sub 2} was done on laboratory level by the hot pressingmore » method, using the plasmochemical calcination technology. To incorporate simulators of plutonium into the structure of ZrSiO{sub 4} and ZrO{sub 2} in the course of synthesis, an original method developed by the authors as a result of studying the high-uranium zircon (Zr,U) SiO{sub 4} form Chernobyl {open_quotes}lavas{close_quotes} was used.« less

Iron and zinc isotope fractionation during uptake and translocation in rice (Oryza sativa) grown in oxic and anoxic soils

NASA Astrophysics Data System (ADS)

Arnold, Tim; Markovic, Tamara; Kirk, Guy J. D.; Schönbächler, Maria; Rehkämper, Mark; Zhao, Fangjie J.; Weiss, Dominik J.

2015-11-01

Stable isotope fractionation is emerging quickly as a powerful novel technique to study metal uptake and translocation in plants. Fundamental to this development is a thorough understanding of the processes that lead to isotope fractionation under differing environmental conditions. In this study, we investigated Zn and Fe isotope fractionation in rice grown to maturity in anaerobic and aerobic soils under greenhouse conditions. The overall Zn isotope fractionation between the soil and above ground plant material was negligible in aerobic soil but significant in anaerobic soil with isotopically lighter Zn in the rice plant. The observed range of fractionation is in line with previously determined fractionations of Zn in rice grown in hydroponic solutions and submerged soils and emphasizes the effect of taking up different chemical forms of Zn, most likely free and organically complexed Zn. The Zn in the grain was isotopically lighter than in the rest of the above ground plant in rice grown in aerobic and anaerobic soils alike. This suggests that in the course of the grain loading and during the translocation within the plant important biochemical and/or biophysical processes occur. The isotope fractionation observed in the grains would be consistent with an unidirectional controlled transport from shoot to grain with a fractionation factor of α ≈ 0.9994. Iron isotopes showed an isotopic lighter signature in shoot and grain compared to the bulk soil or the leachate in aerobic and anaerobic soils alike. The negative direction of isotopic fractionation is consistent with possible changes in the redox state of Fe occurring during the uptake and translocation processes. The isotope fractionation pattern between shoots and grain material are different for Zn and Fe which finally suggests that different mechanisms operate during translocation and grain-loading in rice for these two key micronutrients.

Zinc

USDA-ARS?s Scientific Manuscript database

Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is ...

Evaluation of isotopic composition of fast reactor core in closed nuclear fuel cycle

NASA Astrophysics Data System (ADS)

Tikhomirov, Georgy; Ternovykh, Mikhail; Saldikov, Ivan; Fomichenko, Peter; Gerasimov, Alexander

2017-09-01

The strategy of the development of nuclear power in Russia provides for use of fast power reactors in closed nuclear fuel cycle. The PRORYV (i.e. «Breakthrough» in Russian) project is currently under development. Within the framework of this project, fast reactors BN-1200 and BREST-OD-300 should be built to, inter alia, demonstrate possibility of the closed nuclear fuel cycle technologies with plutonium as a main source of energy. Russia has a large inventory of plutonium which was accumulated in the result of reprocessing of spent fuel of thermal power reactors and conversion of nuclear weapons. This kind of plutonium will be used for development of initial fuel assemblies for fast reactors. The closed nuclear fuel cycle concept of the PRORYV assumes self-supplied mode of operation with fuel regeneration by neutron capture reaction in non-enriched uranium, which is used as a raw material. Operating modes of reactors and its characteristics should be chosen so as to provide the self-sufficient mode by using of fissile isotopes while refueling by depleted uranium and to support this state during the entire period of reactor operation. Thus, the actual issue is modeling fuel handling processes. To solve these problems, the code REPRORYV (Recycle for PRORYV) has been developed. It simulates nuclide streams in non-reactor stages of the closed fuel cycle. At the same time various verified codes can be used to evaluate in-core characteristics of a reactor. By using this approach various options for nuclide streams and assess the impact of different plutonium content in the fuel, fuel processing conditions, losses during fuel processing, as well as the impact of initial uncertainties on neutron-physical characteristics of reactor are considered in this study.

Zinc and Chlamydia trachomatis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugarman, B.; Epps, L.R.

1985-07-01

Zinc was noted to have significant effects upon the infection of McCoy cells by each of two strains of Chlamydia trachomatis. With a high or low Chlamydia inoculant, the number of infected cells increased up to 200% utilizing supplemental zinc (up to 1 x 10/sup -4/ M) in the inoculation media compared with standard Chlamydia cultivation media (8 x 10/sup -6/ M zinc). Ferric chloride and calcium chloride did not effect any such changes. Higher concentrations of zinc, after 2 hr of incubation with Chlamydia, significantly decreased the number of inclusions. This direct effect of zinc on the Chlamydia remainedmore » constant after further repassage of the Chlamydia without supplemental zinc, suggesting a lethal effect of the zinc. Supplemental zinc (up to 10/sup -4/ M) may prove to be a useful addition to inoculation media to increase the yield of culturing for Chlamydia trachomatis. Similarly, topical or oral zinc preparations used by people may alter their susceptibility to Chamydia trachomatis infections.« less

PLATINUM HEXAFLUORIDE AND METHOD OF FLUORINATING PLUTONIUM CONTAINING MIXTURES THERE-WITH

DOEpatents

Malm, J.G.; Weinstock, B.; Claassen, H.H.

1959-07-01

The preparation of platinum hexafluoride and its use as a fluorinating agent in a process for separating plutonium from fission products is presented. According to the invention, platinum is reacted with fluorine gas at from 900 to 1100 deg C to form platinum hexafluoride. The platinum hexafluoride is then contacted with the plutonium containing mixture at room temperature to form plutonium hexafluoride which is more volatile than the fission products fluorides and therefore can be isolated by distillation.

Plutonium-related work and cause-specific mortality at the United States Department of Energy Hanford Site.

PubMed

Wing, Steve; Richardson, David; Wolf, Susanne; Mihlan, Gary

2004-02-01

Health effects of working with plutonium remain unclear. Plutonium workers at the United States Department of Energy (US-DOE) Hanford Site in Washington State, USA were evaluated for increased risks of cancer and non-cancer mortality. Periods of employment in jobs with routine or non-routine potential for plutonium exposure were identified for 26,389 workers hired between 1944 and 1978. Life table regression was used to examine associations of length of employment in plutonium jobs with confirmed plutonium deposition and with cause specific mortality through 1994. Incidence of confirmed internal plutonium deposition in all plutonium workers was 15.4 times greater than in other Hanford jobs. Plutonium workers had low death rates compared to other workers, particularly for cancer causes. Mortality for several causes was positively associated with length of employment in routine plutonium jobs, especially for employment at older ages. At ages 50 and above, death rates for non-external causes of death, all cancers, cancers of tissues where plutonium deposits, and lung cancer, increased 2.0 +/- 1.1%, 2.6 +/- 2.0%, 4.9 +/- 3.3%, and 7.1 +/- 3.4% (+/-SE) per year of employment in routine plutonium jobs, respectively. Workers employed in jobs with routine potential for plutonium exposure have low mortality rates compared to other Hanford workers even with adjustment for demographic, socioeconomic, and employment factors. This may be due, in part, to medical screening. Associations between duration of employment in jobs with routine potential for plutonium exposure and mortality may indicate occupational exposure effects. Copyright 2004 Wiley-Liss, Inc.

PROCESS USING BISMUTH PHOSPHATE AS A CARRIER PRECIPITATE FOR FISSION PRODUCTS AND PLUTONIUM VALUES

DOEpatents

Finzel, T.G.

1959-03-10

A process is described for separating plutonium from fission products carried therewith when plutonium in the reduced oxidation state is removed from a nitric acid solution of irradiated uranium by means of bismuth phosphate as a carrier precipitate. The bismuth phosphate carrier precipitate is dissolved by treatment with nitric acid and the plutonium therein is oxidized to the hexavalent oxidation state by means of potassium dichromate. Separation of the plutonium from the fission products is accomplished by again precipitating bismuth phosphate and removing the precipitate which now carries the fission products and a small percentage of the plutonium present. The amount of plutonium carried in this last step may be minimized by addition of sodium fluoride, so as to make the solution 0.03N in NaF, prior to the oxidation and prccipitation step.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerber, Mark A.; Schmidt, Andrew J.; Delegard, Calvin H.

2000-09-28

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

Association between Maternal Zinc Status, Dietary Zinc Intake and Pregnancy Complications: A Systematic Review

PubMed Central

Wilson, Rebecca L.; Grieger, Jessica A.; Bianco-Miotto, Tina; Roberts, Claire T.

2016-01-01

Adequate zinc stores in the body are extremely important during periods of accelerated growth. However, zinc deficiency is common in developing countries and low maternal circulating zinc concentrations have previously been associated with pregnancy complications. We reviewed current literature assessing circulating zinc and dietary zinc intake during pregnancy and the associations with preeclampsia (PE); spontaneous preterm birth (sPTB); low birthweight (LBW); and gestational diabetes (GDM). Searches of MEDLINE; CINAHL and Scopus databases identified 639 articles and 64 studies were reviewed. In 10 out of 16 studies a difference was reported with respect to circulating zinc between women who gave birth to a LBW infant (≤2500 g) and those who gave birth to an infant of adequate weight (>2500 g), particularly in populations where inadequate zinc intake is prevalent. In 16 of our 33 studies an association was found between hypertensive disorders of pregnancy and circulating zinc; particularly in women with severe PE (blood pressure ≥160/110 mmHg). No association between maternal zinc status and sPTB or GDM was seen; however; direct comparisons between the studies was difficult. Furthermore; only a small number of studies were based on women from populations where there is a high risk of zinc deficiency. Therefore; the link between maternal zinc status and pregnancy success in these populations cannot be established. Future studies should focus on those vulnerable to zinc deficiency and include dietary zinc intake as a measure of zinc status. PMID:27754451

Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

DOEpatents

McQuaid, James H.; Lavietes, Anthony D.

1998-05-29

A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radio nuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components.

Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

DOEpatents

McQuaid, J.H.; Lavietes, A.D.

1998-05-26

A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector is disclosed. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radionuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components. 9 figs.

Dehydration of plutonium or neptunium trichloride hydrate

DOEpatents

Foropoulos, Jr., Jerry; Avens, Larry R.; Trujillo, Eddie A.

1992-01-01

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

Dehydration of plutonium or neptunium trichloride hydrate

DOEpatents

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

1992-03-24

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

PLUTONIUM-URANIUM ALLOY

DOEpatents

Coffinberry, A.S.; Schonfeld, F.W.

1959-09-01

Pu-U-Fe and Pu-U-Co alloys suitable for use as fuel elements tn fast breeder reactors are described. The advantages of these alloys are ease of fabrication without microcracks, good corrosion restatance, and good resistance to radiation damage. These advantages are secured by limitation of the zeta phase of plutonium in favor of a tetragonal crystal structure of the U/sub 6/Mn type.

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

DOEpatents

Angerman, A.A.

1958-10-21

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

Development of first ever scanning probe microscopy capabilities for plutonium

DOE PAGES

Beaux, Miles F.; Cordoba, Miguel Santiago; Zocco, Adam T.; ...

2017-04-01

Scanning probe microscopy capabilities have been developed for plutonium and its derivative compounds. Specifically, a scanning tunneling microscope and an atomic force microscope housed in an ultra-high vacuum system and an inert atmosphere glove box, respectively, were prepared for the introduction of small non-dispersible δ-Pu coupons. Experimental details, procedures, and preliminary imaging of δ-Pu coupons are presented to demonstrate the functionality of these new capabilities. In conclusion, these first of a kind capabilities for plutonium represent a significant step forward in the ability to characterize and understand plutonium surfaces with high spatial resolution.

A review of plutonium oxalate decomposition reactions and effects of decomposition temperature on the surface area of the plutonium dioxide product

NASA Astrophysics Data System (ADS)

Orr, R. M.; Sims, H. E.; Taylor, R. J.

2015-10-01

Plutonium (IV) and (III) ions in nitric acid solution readily form insoluble precipitates with oxalic acid. The plutonium oxalates are then easily thermally decomposed to form plutonium dioxide powder. This simple process forms the basis of current industrial conversion or 'finishing' processes that are used in commercial scale reprocessing plants. It is also widely used in analytical or laboratory scale operations and for waste residues treatment. However, the mechanisms of the thermal decompositions in both air and inert atmospheres have been the subject of various studies over several decades. The nature of intermediate phases is of fundamental interest whilst understanding the evolution of gases at different temperatures is relevant to process control. The thermal decomposition is also used to control a number of powder properties of the PuO2 product that are important to either long term storage or mixed oxide fuel manufacturing. These properties are the surface area, residual carbon impurities and adsorbed volatile species whereas the morphology and particle size distribution are functions of the precipitation process. Available data and experience regarding the thermal and radiation-induced decompositions of plutonium oxalate to oxide are reviewed. The mechanisms of the thermal decompositions are considered with a particular focus on the likely redox chemistry involved. Also, whilst it is well known that the surface area is dependent on calcination temperature, there is a wide variation in the published data and so new correlations have been derived. Better understanding of plutonium (III) and (IV) oxalate decompositions will assist the development of more proliferation resistant actinide co-conversion processes that are needed for advanced reprocessing in future closed nuclear fuel cycles.

METHOD OF DISSOLVING MASSIVE PLUTONIUM

DOEpatents

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

1960-06-28

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

Assessment of plutonium in the Savannah River Site environment. Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlton, W.H.; Evans, A.G.; Geary, L.A.

1992-12-31

Plutonium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fifth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. These are living documents, each to be revised and updated on a two-year schedule. This document describes the sources of plutonium in the environment, its release from SRS, environmental transport and ecological concentration of plutonium, and the radiological impact of SRS releases to the environment. Plutonium exists in the environment as a result of above-ground nuclearmore » weapons tests, the Chernobyl accident, the destruction of satellite SNAP 9-A, plane crashes involving nuclear weapons, and small releases from reactors and reprocessing plants. Plutonium has been produced at SRS during the operation of five production reactors and released in small quantities during the processing of fuel and targets in chemical separations facilities. Approximately 0.6 Ci of plutonium was released into streams and about 12 Ci was released to seepage basins, where it was tightly bound by clay in the soil. A smaller quantity, about 3.8 Ci, was released to the atmosphere. Virtually all releases have occurred in F- and H-Area separation facilities. Plutonium concentration and transport mechanisms for the atmosphere, surface water, and ground water releases have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases to the offsite maximum individual can be characterized by a total dose of 15 mrem (atmospheric) and 0.18 mrem (liquid), compared with the dose of 12,960 mrem from non-SRS sources during the same period of time (1954--1989). Plutonium releases from SRS facilities have resulted in a negligible impact to the environment and the population it supports.« less

Structures of plutonium coordination compounds: A review of past work, recent single crystal x-ray diffraction results, and what we're learning about plutonium coordination chemistry

NASA Astrophysics Data System (ADS)

Neu, M. P.; Matonic, J. H.; Smith, D. M.; Scott, B. L.

2000-07-01

The compounds we have isolated and characterized include plutonium(III) and plutonium(IV) bound by ligands with a range of donor types and denticity (halide, phosphine oxide, hydroxamate, amine, sulfide) in a variety of coordination geometries. For example, we have obtained the first X-ray structure of Pu(III) complexed by a soft donor ligand. Using a "one pot" synthesis beginning with Pu metal strips and iodine in acetonitrile and adding trithiacyclononane we isolated the complex, PuI3(9S3)(MeCN)2 (Figure 1). On the other end of the coordination chemistry spectrum, we have obtained the first single crystal structure of the Pu(IV) hexachloro anion (Figure 2). Although this species has been used in plutonium purification via anion exchange chromatography for decades, the bond distances and exact structure were not known. We have also characterized the first plutonium-biomolecule complex, Pu(IV) bound by the siderophore desferrioxamine E.In this presentation we will review the preparation, structures, and importance of previously known coordination compounds and of those we have recently isolated. We will show the coordination chemistry of plutonium is rich and varied, well worth additional exploration.

Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

PubMed

Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

2016-04-25

Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process.

Functional studies of Drosophila zinc transporters reveal the mechanism for dietary zinc absorption and regulation

PubMed Central

2013-01-01

Background Zinc is key to the function of many proteins, but the process of dietary zinc absorption is not well clarified. Current knowledge about dietary zinc absorption is fragmented, and mostly derives from incomplete mammalian studies. To gain a comprehensive picture of this process, we systematically characterized all zinc transporters (that is, the Zip and ZnT family members) for their possible roles in dietary zinc absorption in a genetically amenable model organism, Drosophila melanogaster. Results A set of plasma membrane-resident zinc transporters was identified to be responsible for absorbing zinc from the lumen into the enterocyte and the subsequent exit of zinc to the circulation. dZip1 and dZip2, two functionally overlapping zinc importers, are responsible for absorbing zinc from the lumen into the enterocyte. Exit of zinc to the circulation is mediated through another two functionally overlapping zinc exporters, dZnT1, and its homolog CG5130 (dZnT77C). Somewhat surprisingly, it appears that the array of intracellular ZnT proteins, including the Golgi-resident dZnT7, is not directly involved in dietary zinc absorption. By modulating zinc status in different parts of the body, we found that regulation of dietary zinc absorption, in contrast to that of iron, is unresponsive to bodily needs or zinc status outside the gut. The zinc transporters that are involved in dietary zinc absorption, including the importers dZip1 and dZip2, and the exporter dZnT1, are respectively regulated at the RNA and protein levels by zinc in the enterocyte. Conclusions Our study using the model organism Drosophila thus starts to reveal a comprehensive sketch of dietary zinc absorption and its regulatory control, a process that is still incompletely understood in mammalian organisms. The knowledge gained will act as a reference for future mammalian studies, and also enable an appreciation of this important process from an evolutionary perspective. PMID:24063361

Experimental and Numerical Investigations on Colloid-facilitated Plutonium Reactive Transport in Fractured Tuffaceous Rocks

NASA Astrophysics Data System (ADS)

Dai, Z.; Wolfsberg, A. V.; Zhu, L.; Reimus, P. W.

2017-12-01

Colloids have the potential to enhance mobility of strongly sorbing radionuclide contaminants in fractured rocks at underground nuclear test sites. This study presents an experimental and numerical investigation of colloid-facilitated plutonium reactive transport in fractured porous media for identifying plutonium sorption/filtration processes. The transport parameters for dispersion, diffusion, sorption, and filtration are estimated with inverse modeling for minimizing the least squares objective function of multicomponent concentration data from multiple transport experiments with the Shuffled Complex Evolution Metropolis (SCEM). Capitalizing on an unplanned experimental artifact that led to colloid formation and migration, we adopt a stepwise strategy to first interpret the data from each experiment separately and then to incorporate multiple experiments simultaneously to identify a suite of plutonium-colloid transport processes. Nonequilibrium or kinetic attachment and detachment of plutonium-colloid in fractures was clearly demonstrated and captured in the inverted modeling parameters along with estimates of the source plutonium fraction that formed plutonium-colloids. The results from this study provide valuable insights for understanding the transport mechanisms and environmental impacts of plutonium in fractured formations and groundwater aquifers.

Fuel bundle design for enhanced usage of plutonium fuel

DOEpatents

Reese, Anthony P.; Stachowski, Russell E.

1995-01-01

A nuclear fuel bundle includes a square array of fuel rods each having a concentration of enriched uranium and plutonium. Each rod of an interior array of the rods also has a concentration of gadolinium. The interior array of rods is surrounded by an exterior array of rods void of gadolinium. By this design, usage of plutonium in the nuclear reactor is enhanced.

Zirconia ceramics for excess weapons plutonium waste

NASA Astrophysics Data System (ADS)

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

2000-01-01

We synthesized a zirconia (ZrO 2)-based single-phase ceramic containing simulated excess weapons plutonium waste. ZrO 2 has large solubility for other metallic oxides. More than 20 binary systems A xO y-ZrO 2 have been reported in the literature, including PuO 2, 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 the cubic modification) can be dissolved in ZrO 2, together with plutonium (simulated by Ce 4+, U 4+ or Th 4+) and impurities (e.g., Ca, Mg, Fe, Si). Sol-gel and powder methods were applied to make homogeneous, single-phase zirconia solid solutions. Pu waste impurities were completely dissolved in the solid solutions. In contrast to other phases, e.g., zirconolite and pyrochlore, zirconia is extremely radiation resistant and does not undergo amorphization. Baddeleyite (ZrO 2) is suggested as the natural analogue to study long-term radiation resistance and chemical durability of zirconia-based waste forms.

Lattice dynamics and elasticity for ε-plutonium [First-principles lattice dynamics for ε-plutonium

DOE PAGES

Söderlind, Per

2017-04-25

Here, lattice dynamics and elasticity for the high-temperature ε phase (body-centered cubic; bcc) of plutonium is predicted utilizing first-principles electronic structure coupled with a self-consistent phonon method that takes phonon-phonon interaction and strong anharmonicity into account. These predictions establish the first sensible lattice-dynamics and elasticity data on ε-Pu. The atomic forces required for the phonon scheme are highly accurate and derived from the total energies obtained from relativistic and parameter-free density-functional theory. The results appear reasonable but no data exist to compare with except those from dynamical mean-field theory that suggest ε-plutonium is mechanically unstable. Fundamental knowledge and understanding ofmore » the high-temperature bcc phase, that is generally present in all actinide metals before melting, is critically important for a proper interpretation of the phase diagram as well as practical modeling of high-temperature properties.« less

a Plutonium Ceramic Target for Masha

NASA Astrophysics Data System (ADS)

Wilk, P. A.; Shaughnessy, D. A.; Moody, K. J.; Kenneally, J. M.; Wild, J. F.; Stoyer, M. A.; Patin, J. B.; Lougheed, R. W.; Ebbinghaus, B. B.; Landingham, R. L.; Oganessian, Yu. Ts.; Yeremin, A. V.; Dmitriev, S. N.

2005-09-01

We are currently developing a plutonium ceramic target for the MASHA mass separator. The MASHA separator will use a thick plutonium ceramic target capable of tolerating temperatures up to 2000 °C. Promising candidates for the target include oxides and carbides, although more research into their thermodynamic properties will be required. Reaction products will diffuse out of the target into an ion source, where they will then be transported through the separator to a position-sensitive focal-plane detector array. Experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments where the chemical properties of the heaviest elements are studied.

A Plutonium Ceramic Target for MASHA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilk, P A; Shaughnessy, D A; Moody, K J

2004-07-06

We are currently developing a plutonium ceramic target for the MASHA mass separator. The MASHA separator will use a thick plutonium ceramic target capable of tolerating temperatures up to 2000 C. Promising candidates for the target include oxides and carbides, although more research into their thermodynamic properties will be required. Reaction products will diffuse out of the target into an ion source, where they will then be transported through the separator to a position-sensitive focal-plane detector array. Experiments on MASHA will allow us to make measurements that will cement our identification of element 114 and provide for future experiments wheremore » the chemical properties of the heaviest elements are studied.« less

AMINE EXTRACTION OF PLUTONIUM FROM NITRIC ACID SOLUTIONS LOADING AND STRIPPING EXPERIMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, A.S.

1961-01-19

Information is presented on a suitable amine processing system for plutonium nitrate. Experiments with concentrated plutonium nitrate solutions show that trilaurylamine (TLA) - xylene solvent systems did not form a second organic phase. Experiments are also reported with tri-noctylamine (TnOA)-xylene and TLA-Amsco - octyl alcohol. Two organic phases appear in both these systems at high plutonium nitrate concentrations. Data are tabulated from loading and stripping experiments. (J.R.D.)

THE CHEMICAL ANALYSIS OF TERNARY ALLOYS OF PLUTONIUM WITH MOLYBDENUM AND URANIUM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, G.; Woodhead, J.; Jenkins, E.N.

1958-09-01

It is shown that the absorptiometric determination of molybdenum as thiocyanate may be used in the presence of plutonium. Molybdenum interferes with previously published methods for determining uranium and plutonium but conditlons have been established for its complete removal by solvent extraction of the compound with alpha -benzoin oxime. The previous methods for uranium and plutonium are satisfactory when applied to the residual aqueous phase following this solvent extraction. (auth)

Zinc triggers microglial activation.

PubMed

Kauppinen, Tiina M; Higashi, Youichirou; Suh, Sang Won; Escartin, Carole; Nagasawa, Kazuki; Swanson, Raymond A

2008-05-28

Microglia are resident immune cells of the CNS. When stimulated by infection, tissue injury, or other signals, microglia assume an activated, "ameboid" morphology and release matrix metalloproteinases, reactive oxygen species, and other proinflammatory factors. This innate immune response augments host defenses, but it can also contribute to neuronal death. Zinc is released by neurons under several conditions in which microglial activation occurs, and zinc chelators can reduce neuronal death in animal models of cerebral ischemia and neurodegenerative disorders. Here, we show that zinc directly triggers microglial activation. Microglia transfected with a nuclear factor-kappaB (NF-kappaB) reporter gene showed a severalfold increase in NF-kappaB activity in response to 30 microm zinc. Cultured mouse microglia exposed to 15-30 microm zinc increased nitric oxide production, increased F4/80 expression, altered cytokine expression, and assumed the activated morphology. Zinc-induced microglial activation was blocked by inhibiting NADPH oxidase, poly(ADP-ribose) polymerase-1 (PARP-1), or NF-kappaB activation. Zinc injected directly into mouse brain induced microglial activation in wild-type mice, but not in mice genetically lacking PARP-1 or NADPH oxidase activity. Endogenous zinc release, induced by cerebral ischemia-reperfusion, likewise induced a robust microglial reaction, and this reaction was suppressed by the zinc chelator CaEDTA. Together, these results suggest that extracellular zinc triggers microglial activation through the sequential activation of NADPH oxidase, PARP-1, and NF-kappaB. These findings identify a novel trigger for microglial activation and a previously unrecognized mechanism by which zinc may contribute to neurological disorders.

PLUTONIUM ALLOYS

DOEpatents

Chynoweth, W.

1959-06-16

The preparation of low-melting-point plutonium alloys is described. In a MgO crucible Pu is placed on top of the lighter alloying metal (Fe, Co, or Ni) and the temperature raised to 1000 or 1200 deg C. Upon cooling, the alloy slug is broke out of the crucible. With 14 at. % Ni the m.p. is 465 deg C; with 9.5 at. % Fe the m.p. is 410 deg C; and with 12.0 at. % Co the m.p. is 405 deg C. (T.R.H.) l6262 l6263 ((((((((Abstract unscannable))))))))

Zinc Information

MedlinePlus

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Zinc starvation induces autophagy in yeast

PubMed Central

Kawamata, Tomoko; Horie, Tetsuro; Matsunami, Miou; Sasaki, Michiko; Ohsumi, Yoshinori

2017-01-01

Zinc is an essential nutrient for all forms of life. Within cells, most zinc is bound to protein. Because zinc serves as a catalytic or structural cofactor for many proteins, cells must maintain zinc homeostasis under severely zinc-deficient conditions. In yeast, the transcription factor Zap1 controls the expression of genes required for uptake and mobilization of zinc, but to date the fate of existing zinc-binding proteins under zinc starvation remains poorly understood. Autophagy is an evolutionarily conserved cellular degradation/recycling process in which cytoplasmic proteins and organelles are sequestered for degradation in the vacuole/lysosome. In this study, we investigated how autophagy functions under zinc starvation. Zinc depletion induced non-selective autophagy, which is important for zinc-limited growth. Induction of autophagy by zinc starvation was not directly related to transcriptional activation of Zap1. Instead, TORC1 inactivation directed zinc starvation-induced autophagy. Abundant zinc proteins, such as Adh1, Fba1, and ribosomal protein Rpl37, were degraded in an autophagy-dependent manner. But the targets of autophagy were not restricted to zinc-binding proteins. When cellular zinc is severely depleted, this non-selective autophagy plays a role in releasing zinc from the degraded proteins and recycling zinc for other essential purposes. PMID:28264932

Cu, Fe, and Zn Isotope Variations Within a High-Temperature Mid-Ocean Ridge Sulfide Structure

NASA Astrophysics Data System (ADS)

Ewing, S. M.; Nelson, B. K.; Kelley, D. S.; Nielsen, D. C.

2006-12-01

Hydrothermal processes at mid-ocean ridges play an important role in controlling the transition metal budget of seawater and the crust through which it circulates. Preliminary work has shown stable metal isotope variations accompany these processes. We report Cu, Zn, and Fe isotope analyses of transects through a high temperature sulfide structure ("Fin") collected during the 1998 Edifice Rex Sulfide Recovery Project. We analyzed two horizontal transects through the sulfide edifice, from inner conduit to outer surface. Transects A and F are 9 and 6 cm in length, respectively. Each displays radially zoned mineralogy progressing from a chalcopyrite (ccp) zone through zones of zinc sulfide, pyrite-anhydrite (pyr-anh) matrix, zinc sulfide-anhydrite (zns-anh) matrix, to an outer well-cemented silica (Si) zone. Additional ccp and pyr-anh zones appear in transect A resulting from a smaller breakout conduit. In transect A, Cu displays the most isotopic variation, with little variation in Fe and Zn isotopes. From the inner ccp zone outward, the Cu isotope profile shows a 0.4‰ (±0.05‰ 2σ) increase in the first pyr-anh zone over the coarse-grained ccp zone. The δ65Cu drops by 0.6‰ in the secondary ccp zone and recovers to values of the innermost wall in the following zone where it is constant until the outermost portion of the Si rich zone, which shows a 1.3‰ increase over inner zone values. The Zn isotope profile has a total variation of 0.27‰ (±0.05‰ 2σ), with a 0.2‰ increase in the first pyr- anh zone followed by a .27‰ decrease in the adjacent zone, and recovering to its heaviest values in the second pyr-anh zone. The Zn profile lacks any significant increase of the δ^{64}Zn in the outermost zones. The Fe isotope profile shows very little variation across the chimney wall, but does have a sharp 0.7‰ (±0.1‰ 2σ) increase in the δ56Fe in the well-cemented Si rich zone. In transect F, the Cu isotope profile again shows the most variation, but

Measurement of (n,α) cross section for set of structural material isotopes

NASA Astrophysics Data System (ADS)

Khryachkov, Vitaly; Gurbich, Alexander; Khromyleva, Tatiana; Bondarenko, Ivan; Ketlerov, Vladimir; Prusachenko, Pavel

2017-09-01

A novel spectrometer was developed and used to measure the cross section for the (n,α) reaction at IPPE. Direct measurements of the α-particles yield from solid isotopic pure targets of 50, 52 and 53 chromium, 54 and 57 iron, 60 nickel, and 64 zinc were carried out in the neutron energy range from 4.7 to 7.2 MeV. For some isotopes the (n,α) reaction cross-section for neutron energies less than 14 MeV were measured for the first time. The result of the comparison of new experimental data with the evaluated data from libraries ENDF/B VII, JENDL 4.0, JEFF 3.1, ROSFOND 2010 and BROND 3 and with the experimental data of other authors is presented.

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

DOEpatents

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

1960-08-23

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

Plutonium segregation in glassy aerodynamic fallout from a nuclear weapon test

DOE PAGES

Holliday, K. S.; Dierken, J. M.; Monroe, M. L.; ...

2017-01-11

Our study combines electron microscopy equipped with energy dispersive spectroscopy to probe major element composition and autoradiography to map plutonium in order to examine the spatial relationships between plutonium and fallout composition in aerodynamic glassy fallout from a nuclear weapon test. We interrogated a sample set of 48 individual fallout specimens in order to reveal that the significant chemical heterogeneity of this sample set could be described compositionally with a relatively small number of compositional endmembers. Furthermore, high concentrations of plutonium were never associated with several endmember compositions and concentrated with the so-called mafic glass endmember. Our result suggests thatmore » it is the physical characteristics of the compositional endmembers and not the chemical characteristics of the individual component elements that govern the un-burnt plutonium distribution with respect to major element composition in fallout.« less

Fuel bundle design for enhanced usage of plutonium fuel

DOEpatents

Reese, A.P.; Stachowski, R.E.

1995-08-08

A nuclear fuel bundle includes a square array of fuel rods each having a concentration of enriched uranium and plutonium. Each rod of an interior array of the rods also has a concentration of gadolinium. The interior array of rods is surrounded by an exterior array of rods void of gadolinium. By this design, usage of plutonium in the nuclear reactor is enhanced. 10 figs.

PROCESS OF SECURING PLUTONIUM IN NITRIC ACID SOLUTIONS IN ITS TRIVALENT OXIDATION STATE

DOEpatents

Thomas, J.R.

1958-08-26

>Various processes for the recovery of plutonium require that the plutonium be obtalned and maintained in the reduced or trivalent state in solution. Ferrous ions are commonly used as the reducing agent for this purpose, but it is difficult to maintain the plutonium in a reduced state in nitric acid solutions due to the oxidizing effects of the acid. It has been found that the addition of a stabilizing or holding reductant to such solution prevents reoxidation of the plutonium. Sulfamate ions have been found to be ideally suitable as such a stabilizer even in the presence of nitric acid.

METHOD OF SEPARATING TETRAVALENT PLUTONIUM VALUES FROM CERIUM SUB-GROUP RARE EARTH VALUES

DOEpatents

Duffield, R.B.; Stoughton, R.W.

1959-02-01

A method is presented for separating plutonium from the cerium sub-group of rare earths when both are present in an aqueous solution. The method consists in adding an excess of alkali metal carbonate to the solution, which causes the formation of a soluble plutonium carbonate precipitate and at the same time forms an insoluble cerium-group rare earth carbonate. The pH value must be adjusted to bctween 5.5 and 7.5, and prior to the precipitation step the plutonium must be reduced to the tetravalent state since only tetravalent plutonium will form the soluble carbonate complex.

Studies on the bioavailability of zinc in humans: intestinal interaction of tin and zinc.