Hydrometallurgical separation of rare earth elements, cobalt and nickel from spent nickel-metal-hydride batteries

Science.gov (United States)

Rodrigues, Luiz Eduardo Oliveira Carmo; Mansur, Marcelo Borges

The separation of rare earth elements, cobalt and nickel from NiMH battery residues is evaluated in this paper. Analysis of the internal content of the NiMH batteries shows that nickel is the main metal present in the residue (around 50% in weight), as well as potassium (2.2-10.9%), cobalt (5.1-5.5%), rare earth elements (15.3-29.0%) and cadmium (2.8%). The presence of cadmium reveals that some Ni-Cd batteries are possibly labeled as NiMH ones. The leaching of nickel and cobalt from the NiMH battery powder with sulfuric acid is efficient; operating variables temperature and concentration of H 2O 2 has no significant effect for the conditions studied. A mixture of rare earth elements is separated by precipitation with NaOH. Finally, solvent extraction with D2EHPA (di-2-ethylhexyl phosphoric acid) followed by Cyanex 272 (bis-2,4,4-trimethylpentyl phosphinic acid) can separate cadmium, cobalt and nickel from the leach liquor. The effect of the main operating variables of both leaching and solvent extraction steps are discussed aiming to maximize metal separation for recycling purposes.

Radionuclide deposition control

International Nuclear Information System (INIS)

1980-01-01

A method is described for controlling the deposition, on to the surfaces of reactor components, of the radionuclides manganese-54, cobalt-58 and cobalt-60 from a liquid stream containing the radionuclides. The method consists of disposing a getter material (nickel) in the liquid stream, and a non-getter material (tantalum, tungsten or molybdenum) as a coating on the surfaces where deposition is not desired. The process is described with special reference to its use in the coolant circuit in sodium cooled fast breeder reactors. (U.K.)

Water hyacinth for phytoremediation of radioactive waste simulate contaminated with cesium and cobalt radionuclides

Energy Technology Data Exchange (ETDEWEB)

Saleh, H.M., E-mail: hosamsaleh70@yahoo.com [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt)

2012-01-15

Highlights: Black-Right-Pointing-Pointer Phytoremediation of radioactive wastes containing {sup 137}Cs and {sup 60}Co radionuclides. Black-Right-Pointing-Pointer Using water hyacinth for radioactive waste treatment. Black-Right-Pointing-Pointer Bioaccumulation of radionuclides from radioactive waste streams. Black-Right-Pointing-Pointer Factors affecting bioaccumulation of {sup 137}Cs and {sup 60}Co using floating plants. - Abstract: Phytoremediation is based on the capability of plants to remove hazardous contaminants present in the environment. This study aimed to demonstrate some factors controlling the phytoremediation efficiency of live floating plant, water hyacinth (Eichhornia crassipes), towards the effluents contaminated with {sup 137}Cs and/or {sup 60}Co. Cesium has unknown vital biological role for plant while cobalt is one of the essential trace elements required for plant. The main idea of this work i.e. using undesirable species, water hyacinth, in purification of radiocontaminated aqueous solutions has been receiving much attention. The controlling factors such as radioactivity concentration, pH values, the amount of biomass and the light were studied. The uptake rate of radiocesium from the simulated waste solution is inversely proportional to the initial activity content and directly proportional to the increase in mass of plant and sunlight exposure. A spiked solution of pH Almost-Equal-To 4.9 was found to be the suitable medium for the treatment process. The uptake efficiency of {sup 137}Cs present with {sup 60}Co in mixed solution was higher than if it was present separately. On the contrary, uptake of {sup 60}Co is affected negatively by the presence of {sup 137}Cs in their mixed solution. Sunlight is the most required factor for the plant vitality and radiation resistance. The results of the present study indicated that water hyacinth may be a potential candidate plant of high concentration ratios (CR) for phytoremediation of radionuclides

Dendrimer-coated magnetic particles for radionuclide separation

NARCIS (Netherlands)

Grüttner, Cordula; Böhmer, Volker; Casnati, Alessandro; Dozol, Jean-Francois; Reinhoudt, David; Reinoso garcia, M.M.; Rudershausen, Sandra; Teller, Joachim; Ungaro, Rocco; Verboom, Willem; Wang, Pingshan

2005-01-01

Magnetic particles were synthesised for radionuclide removal from nuclear wastes by magnetic separation. Dendrimers with terminal amino groups attached to the particle surface were used to bind chelating groups for lanthanides and actinides. This led to a 50–400-fold increase of the distribution

Sorbent application on the base of chitosan for radionuclides separation

International Nuclear Information System (INIS)

Pivarciova, L.

2016-01-01

Radioactive waste contains enormous amounts of radionuclides, which pollute the environment and can cause serious chemical and radiological toxicity threats to lower and higher living organism. Alternative process for the removal of heavy metal ions and radionuclides is sorption, which utilizes various certain natural materials of biological origin. Amino-polysaccharide-based sorbents e.g. chitosan represent suitable materials for binding of metal oxo-anion species because of numerous functional groups -OH and -NH_2 because of their suitable H-bond donor and acceptor sites. The sorbents on the base chitosan prepared through chemical modification were used for removal and separation certain radionuclides from aqueous media. The aim of this work was the study of physicochemical properties of prepared sorbents. The specific surface of sorbents was characterized with BET methods. Point of zero charge was identified with potentiometric titration. The size of particles and shape of sorbents were determined by scanning electron microscope. The sorption experiments for selected radionuclides were conducted under static and dynamic conditions. The effect of various parameters on the sorption "9"9"mTc, "6"0Co and the effect of pH on the separation of radionuclide mixture in the solution were studied. (author)

Metabolism of radionuclides in domestic animals

International Nuclear Information System (INIS)

Wirth, E.; Leising, C.

1986-01-01

The reactor accident at Chernobyl has shown that shortly after the contamination of the environment radionuclides can be found in animal products. The main contamination pathways of domestic animas are: uptake of radionuclides by foodstuffs; uptake of radionuclides by contaminated drinking water; uptake of radionuclides by inhalation; uptake of radionuclides through skin; uptake of radionuclides by ingestion of soil particles. Generally the uptake of radionuclides by food is the dominant exposure pathway. In rare cases the inhalation of radionuclides or the uptake by drinking water may be of importance. The metabolism of incorporated radionuclides is comparable to the respective metabolism of essential mass or trace elements or heavy metals. Radioisotopes of essential elements are for instance iron 55, manganese 54, cobalt 58 and cobalt 60. Other elements are typical antagonists to essential elements, e.g. strontium 90 is an antagonist to calcium or cesium 137 to potassium. Lead 210 and plutonium 239 behave similarly as heavy metals. Generally the knowledge of the metabolism of trace and mass elements, of antagonistic and synergistic elements and heavy metals can be applied to these radionuclides

Separation of iron and cobalt using 59Fe and 60Co by dialysis of polyvinylpyrrolidone-metal complexes: A greener approach

International Nuclear Information System (INIS)

Lahiri, Susanta; Sarkar, Soumi

2007-01-01

An environmentally benign method to separate iron and cobalt has been developed using a safe chemical, polyvinylpyrrolidone (PVP). The method involves dialysis of PVP-Fe and PVP-Co complexes against triple-distilled water. 59 Fe and 60 Co were used as radioactive tracers of iron and cobalt throughout the experiment. No other chemicals are required for clean separation of cobalt from iron. The optimum condition for separation has been obtained at pH 5 using 10% aqueous solution of PVP. The method is applicable from trace scale to macro-scale. Very high separation factors have been obtained

Radioactive and stable cobalt concentrations in mussel in Kyushu island, Japan

International Nuclear Information System (INIS)

Momoshima, Noriyuki; Shiki, Atsushi; Takashima, Yoshimasa; Maki, Takao; Koriyama, Munehiro; Shimozono, Seika; Imamura, Hiroka; Nakamata, Kojiro.

1985-01-01

Two kinds of mussel, Septifer virgatus and Mytilus edulis, were collected from Kyushu island, Japan, in order to elucidate a background level of 60 Co, which is one of the most significant radionuclide for environmental monitoring around a nuclear power plant. The mussels were collected from 7 locations in 1983 and classified 2 or 3 groups depending on their shell size at each location. Activities of 60 Co were measured by a low-background β counter after purified by means of chemical separation and electrodeposition. Stable cobalt concentrations were determined by colorimetric method. The concentrations of cobalt in Septifer virgatus are one order higher level than that in Mytilus edulis. There are not so large difference in cobalt content depending on shell size so long as comparing them at the same location. The radioactivities in mussels show the same trend as stable cobalt. It has become apparent that Septifer virgatus has a tendency to concentrate cobalt with growing but Mytilus edulis is opposite. The cobalt-60 introduced to sea from nuclear explosions seems to be relatively constant in coastal seawater since specific activities are distributed in a narrow range in spite of kind, shell size and location. (author)

Metabolism of radionuclides in a cephalopod, Iidako, Octopus ocellatus

Energy Technology Data Exchange (ETDEWEB)

Koyanagi, T.; Nakahara, M.; Matsuba, M.; Hirano, S. (National Inst. of Radiological Sciences, Nakaminato, Ibaraki (Japan). Nakaminato Lab. Branch Office)

1982-03-01

Retention, distribution and excretion of radionuclides in a cephalopod, Iidako, Octopus ocellatus, were observed by administering radioisotopes (/sup 54/Mn-, /sup 59/Fe-, /sup 60/Co-, /sup 65/Zn-chlorides and /sup 57/Co-cyanocobalamin) into the mantle cavity by injection. Whole body radioactivity of the octopus was measured periodically after the injection for one to ten weeks to obtain the retention curve. At different stages after the injection, the sacrificed octopus was dissected into eight parts to examine the distribution of radionuclides and its change with the lapse of time. For some organs of the octopus, gel filtration chromatography (GFC) with Sephadex G-75 was applied to elucidate the binding of radionuclides with the constituents of the octopus. Excretion patterns consisted of two or three components for every nuclides except /sup 57/Co-cyanocobalamin which showed monophasic elimination. /sup 54/Mn was lost most rapidly whereas the longest biological half-life was shown by /sup 59/Fe. The most significant distribution of radioactivity was observed for sup(57,60)Co and /sup 59/Fe in the branchial heart of the octopus, while no specific accumulation of /sup 54/Mn and /sup 65/Zn was shown in this organ. The different accumulation mechanisms between each chemical form of cobalt and among the nuclides were suggested from the GFC elution profiles of radioactivity in the branchial heart and the liver.

Metabolism of radionuclides in a cephalopod, Iidako, Octopus ocellatus

International Nuclear Information System (INIS)

Koyanagi, Taku; Nakahara, Motokazu; Matsuba, Mitsue; Hirano, Shigeki

1982-01-01

Retention, distribution and excretion of radionuclides in a cephalopod, Iidako, Octopus ocellatus, were observed by administering radioisotopes ( 54 Mn-, 59 Fe-, 60 Co-, 65 Zn-chlorides and 57 Co-cyanocobalamin) into the mantle cavity by injection. Whole body radioacti vity of the octopus was measured periodically after the injection for one to ten weeks to obtain t he retention curve. At different stages after the injection, the sacrificed octopus was dissected into eight parts to examine the distribution of radionuclides and its change with the lapse of time. For some organs of the octopus, gel filtration chromatography (GFC) with Sephadex G-75 was applied to elucidate the binding of radionuclides with the constituents of the octopus. Excretion patterns consisted of two or three components for every nuclides except 57 Co-cyanocobalamin which showed monophasic elimination. 54 Mn was lost most rapidly whereas the longest biological half-life was shown by 59 Fe. The most significant distribution of radioactivity was observed for sup(57,60)Co and 59 Fe in the branchial heart of the octopus, while no specific accumulation of 54 Mn and 65 Zn was shown in this organ. The different accumulation mechanisms between each chemical form of cobalt and among the nuclides were suggested from the GFC elution profiles of radioactivity in the branchial heart and the liver. (author)

Radionuclide separations and processing for defense water management

International Nuclear Information System (INIS)

Fryberger, T.B.

1993-01-01

An overview is given of the Department of Energy's Efficient Separations and Processing Integrated Program (ESPIP). This program sponsors research in advanced chemical separations for removal of radionuclides and hazardous components from radioactive defense wastes. Separations processing will reduce the volume of high-level waste that must be disposed of in a deep geological repository and will improve the quality of low-level wastes acceptable for near-surface disposal. DOE defense complex processing needs as well as technologies that are currently under development in the program are discussed

Separation Techniques for Quantification of Radionuclides in Environmental Samples

Directory of Open Access Journals (Sweden)

Dusan Galanda

2009-01-01

Full Text Available The reliable and quantitative measurement of radionuclides is important in order to determine environmental quality and radiation safety, and to monitor regulatory compliance. We examined soil samples from Podunajske Biskupice, near the city of Bratislava in the Slovak Republic, for the presence of several natural (238U, 232Th, 40K and anthropogenic (137Cs, 90Sr, 239Pu, 240Pu, 241Am radionuclides. The area is adjacent to a refinery and hazardous waste processing center, as well as the municipal incinerator plant, and so might possess an unusually high level of ecotoxic metals. We found that the levels of both naturally occurring and anthropogenic radionuclides fell within the expected ranges, indicating that these facilities pose no radiological threat to the local environment. During the course of our analysis, we modified existing techniques in order to allow us to handle the unusually large and complex samples that were needed to determine the levels of 239Pu, 240Pu, and 241Am activity. We also rated three commercial techniques for the separation of 90Sr from aqueous solutions and found that two of them, AnaLig Sr-01 and Empore Extraction Disks, were suitable for the quantitative and reliable separation of 90Sr, while the third, Sr-Spec Resin, was less so. The main criterion in evaluating these methods was the chemical recovery of 90Sr, which was less than we had expected. We also considered speed of separation and additional steps needed to prepare the sample for separation.

Aspartic acid interaction with cobalt(II) in dilute aqueous solution: A 57Co emission Mössbauer spectroscopic study

International Nuclear Information System (INIS)

Kamnev, Alexander A.; Tugarova, Anna V.; Kovács, Krisztina; Homonnay, Zoltan; Kuzmann, Erno; Vértes, Attila

2012-01-01

Emission ( 57 Co) Mössbauer spectra of the aspartic acid— 57 CoCl 2 system were measured at T = 80 K in frozen aqueous solution and in the form of a dried residue of this solution. The Mössbauer spectra, besides a weak contribution from after-effects, showed two Fe 2 +  /Co 2 +  components which were ascribed to octahedrally and tetrahedrally coordinated 57 Co II microenvironments in the Asp–cobalt(II) complex. This dual coordination mode may be due to the involvement of the second terminal carboxylic group of aspartic acid in the coordination sphere of Co.

Aspartic acid interaction with cobalt(II) in dilute aqueous solution: A {sup 57}Co emission Moessbauer spectroscopic study

Energy Technology Data Exchange (ETDEWEB)

Kamnev, Alexander A.; Tugarova, Anna V. [Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences (Russian Federation); Kovacs, Krisztina; Homonnay, Zoltan, E-mail: homonnay@ludens.elte.hu; Kuzmann, Erno; Vertes, Attila [Eoetvoes Lorand University, Institute of Chemistry (Hungary)

2012-03-15

Emission ({sup 57}Co) Moessbauer spectra of the aspartic acid-{sup 57}CoCl{sub 2} system were measured at T = 80 K in frozen aqueous solution and in the form of a dried residue of this solution. The Moessbauer spectra, besides a weak contribution from after-effects, showed two Fe{sup 2 + }/Co{sup 2 + } components which were ascribed to octahedrally and tetrahedrally coordinated {sup 57}Co{sup II} microenvironments in the Asp-cobalt(II) complex. This dual coordination mode may be due to the involvement of the second terminal carboxylic group of aspartic acid in the coordination sphere of Co.

Separation of protactinum, actinium, and other radionuclides from proton irradiated thorium target

Science.gov (United States)

Fassbender, Michael E.; Radchenko, Valery

2018-04-24

Protactinium, actinium, radium, radiolanthanides and other radionuclide fission products were separated and recovered from a proton-irradiated thorium target. The target was dissolved in concentrated HCl, which formed anionic complexes of protactinium but not with thorium, actinium, radium, or radiolanthanides. Protactinium was separated from soluble thorium by loading a concentrated HCl solution of the target onto a column of strongly basic anion exchanger resin and eluting with concentrated HCl. Actinium, radium and radiolanthanides elute with thorium. The protactinium that is retained on the column, along with other radionuclides, is eluted may subsequently treated to remove radionuclide impurities to afford a fraction of substantially pure protactinium. The eluate with the soluble thorium, actinium, radium and radiolanthanides may be subjected to treatment with citric acid to form anionic thorium, loaded onto a cationic exchanger resin, and eluted. Actinium, radium and radiolanthanides that are retained can be subjected to extraction chromatography to separate the actinium from the radium and from the radio lanthanides.

Methods radiation protection data sheets for the use radionuclides in unsealed sources

International Nuclear Information System (INIS)

Anon.

1999-01-01

These radiation protection data sheets are devoted to responsible persons and employees of various laboratories or medical, pharmaceutical, university and industrial departments where radionuclides are handled as well as all the persons who attend to safety in this field. They contain the essential radiation protection data for the use of radionuclides in unsealed sources: physical characteristics, risk assessment, administrative procedures, recommendations, regulations and bibliography. This new series includes the following radionuclides: bromine 82, cobalt 58, cobalt 60, manganese 54, mercury 197, mercury 203, promethium 147, xenon 133 and ytterbium 169. (O.M.)

Recovery of Cobalt as Cobalt Oxalate from Cobalt Tailings Using Moderately Thermophilic Bioleaching Technology and Selective Sequential Extraction

Directory of Open Access Journals (Sweden)

Guobao Chen

2016-07-01

Full Text Available Cobalt is a very important metal which is widely applied in various critical areas, however, it is difficult to recover cobalt from minerals since there is a lack of independent cobalt deposits in nature. This work is to provide a complete process to recover cobalt from cobalt tailings using the moderately thermophilic bioleaching technology and selective sequential extraction. It is found that 96.51% Co and 26.32% Cu were extracted after bioleaching for four days at 10% pulp density. The mean compositions of the leach solutions contain 0.98 g·L−1 of Co, 6.52 g·L−1 of Cu, and 24.57 g·L−1 of Fe (III. The copper ion was then recovered by a solvent extraction process and the ferric ions were selectively removed by applying a goethite deironization process. The technological conditions of the above purification procedures were deliberately discussed. Over 98.6% of copper and 99.9% of ferric ions were eliminated from the leaching liquor. Cobalt was finally produced as cobalt oxalate and its overall recovery during the whole process was greater than 95%. The present bioleaching process of cobalt is worth using for reference to deal with low-grade cobalt ores.

Use of membrane separation processes for the separation of radionuclides from liquid and gas streams

International Nuclear Information System (INIS)

Vladisavljevic, G.T.; Rajkovic, M.B.

1999-01-01

Use of membranes for the separation and recovery of radionuclides from contaminated liquid and gas streams has been discussed in this paper. The special attention has been paid to the use of ion-exchange membranes for electrodialysis and Donnan dialysis, as well as the use of facilitated liquid membranes for liquid pertraction. (author)

Separation of Alkyne Enantiomers by Chiral Column HPLC Analysis of Their Cobalt-Complexes

Directory of Open Access Journals (Sweden)

Qiaoyun Liu

2017-03-01

Full Text Available Separation of the enantiomers of new chiral alkynes in strategic syntheses and bioorthogonal studies is always problematic. The chiral column high-performance liquid chromatography (HPLC method in general could not be directly used to resolve such substrates, since the differentiation of the alkyne segment with the other alkane/alkene segment is not significant in the stationary phase, and the alkyne group is not a good UV chromophore. Usually, a pre-column derivatization reaction with a tedious workup procedure is needed. Making use of easily-prepared stable alkyne-cobalt-complexes, we developed a simple and general method by analyzing the in situ generated cobalt-complex of chiral alkynes using chiral column HPLC. This new method is especially suitable for the alkynes without chromophores and other derivable groups.

Radionuclides in Canada goose eggs

International Nuclear Information System (INIS)

Rickard, W.H.; Sweany, H.A.

1975-01-01

Low levels of radionuclides were measured in Canada goose eggs taken from deserted nests from Columbia River islands on the Energy Research and Development Administration's Hanford Reservation. Potassium-40, a naturally occurring radionuclide, was the most abundant radionuclide measured in egg contents and egg shell. Strontium-90 was incorporated into egg shells and cesium-137 into inner egg contents. Manganese-54, cobalt-60, and zinc-65 were more abundant in inner egg contents than in egg shell. Cerium-144 was detected in egg shell but not in inner shell

Selective separation of radionuclides from nuclear waste solutions with inorganic ion exchangers

International Nuclear Information System (INIS)

Lehto, J.; Harjula, R.

1999-01-01

Nuclear industry produces and stores large volumes of radioactive waste solutions. Removal of radionuclides from the solutions is an important and challenging task for two main reasons: reductions in the volumes of solidified waste, which have to be disposed of, and reductions in the radioactive discharges into the environment. Since the radioactive elements in most waste solutions are in trace concentrations and the waste solutions contain large excesses of inactive metal ions, highly selective separation methods are needed for the removal of radionuclides. A number of inorganic ion exchange materials are very selective to key radionuclides and they can play an important role in solving these problems. The spectrum of nuclear waste solutions is rather wide considering their radionuclide contents, concentrations of interfering salts and acidity/alkalinity. Therefore, several inorganic ions exchangers are needed for the removal of most harmful radionuclides from a variety of solutions. This paper discusses the use and requirements of inorganic ion exchange materials in nuclear waste management. Special attention is paid to the novel ion exchange materials developed in the Laboratory of Radiochemistry, University of Helsinki. (orig.)

PENYERAPAN COBALT-60 DARI AIR OLEH TANAMAN KIAPU (Pistia stratiotes L.)

OpenAIRE

Lailatul Nuzzulul Safitri; Poppy Intan Tjahaja; Ida Bagus Made Suryatika

2015-01-01

Has conducted research Cobalt-60 radionuclide uptake by plants kiapu (Pistia stratiotes L.) found in many waters. The purpose of the study was to determine the value of the transfer factor on plant kiapu to Cobalt-60 in water. The study was conducted by growing plants on media kiapu gutter water in pots with the height 35 cm and diameter 11,5 cm containing Cobalt-60. The amount of Cobalt - 60 is absorbed and accumulated by the plant parts, i.e. roots and leaves, was observed by measuring the ...

Cobalt

International Nuclear Information System (INIS)

Stolyarova, I.A.; Bunakova, N.Yu.

1983-01-01

The neutron-activation method for determining cobalt in rocks, polymetallic and iron ores and rockforming minerals at 2x10 -6 -5x10 -3 % content is developed. Cobalt determination is based on the formation under the effect of thermal neutrons of nuclear reactor of the 60 Co radioactive isotope by the 59 Co (n, γ) 60 Co reaction with radiation energy of the most intensive line of 1333 keV. Cobalt can be determined by the scheme of the multicomponent analysis from the sample with other elements. Co is determined in the solution after separation of all determinable by the scheme elements. The 60 Co intensity is measured by the mUltichannel gamma-spectrometer with Ge(Li)-detector

Process and system to control manganese and cobalt isotopes deposits from the cooling fluid of a reactor

International Nuclear Information System (INIS)

Brehm, W.F.; McGuire, J.C.

1978-01-01

Process for controlling the deposition of manganese-54, cobalt-58 and cobalt-60 radionuclides on component surfaces, as from a liquid flow containing these nuclides and entering into contact with the surface of these components. It is characterised by the positioning of a getter forming substance in the liquid flow to collect these radionuclides on the getter forming substance which contains at least 73% nickel by weight [fr

Trace cobalt speciation in bacteria and at enzymic active sites using emission Moessbauer spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Kamnev, A.A.; Antonyuk, L.P.; Smirnova, V.E.; Serebrennikova, O.B. [Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov (Russian Federation); Kulikov, L.A.; Perfiliev, Yu.D. [Laboratory of Nuclear Chemistry Techniques, Department of Radiochemistry, Faculty of Chemistry, Moscow State University (Russian Federation)

2002-02-01

{sup 57}Co emission Moessbauer spectroscopy (EMS) allows the chemical state of cobalt, as influenced by its coordination environment, to be monitored in biological samples at its physiological (trace) concentrations. To draw attention to EMS as a valuable tool for speciation of cobalt in biocomplexes, the process of cobalt(II) metabolism in cells of the plant growth-promoting rhizobacterium Azospirillum brasilense Sp245 was investigated using EMS of {sup 57}Co{sup II}-doped bacterial cells. EMS measurements also showed {sup 57}Co{sup II}-activated glutamine synthetase (GS, a key enzyme of nitrogen metabolism, isolated from this bacterium) to have two different cobalt(II) forms at its active sites, in agreement with data available on other bacterial GSs. Chemical after-effects following electron capture by the nucleus of the parent {sup 57}Co{sup II} during the {sup 57}Co{yields}{sup 57}Fe transition, which contribute to the formation of a stabilised daughter {sup 57}Fe{sup III} component along with the nucleogenic {sup 57}Fe{sup II} forms, are also briefly considered. (orig.)

Cobalt accumulation and circulation by blackgum trees

International Nuclear Information System (INIS)

Thomas, W.A.

1975-01-01

Blackgum (Nyssa sylvatica Marsh.) trees accumulate far greater concentrations of cobalt in mature foliage than do other species on the same site (363 ppM in ash of blackgum, compared with about 3 ppM by mockernut hickory and about 1 ppM by red maple, tulip tree, and white oak). Cobalt concentrations in dormant woody tissues of blackgum also significantly exceed those in the other four species. Inoculation of six blackgums with 60 Co revealed that cobalt remains mobile in the trees for at least 3 years. Foliar concentrations of stable cobalt increase uniformly until senescence. In late August, foliage accounts for only 9 percent of total tree weight but 57 percent of total tree cobalt. Losses of cobalt from trees occur almost entirely by leaf abscission, and the loss rates of weight and cobalt from decomposing litter are similar. Retention of cobalt in the biologically active soil layers perpetuates zones of cobalt concentration created by this species in woodlands

Brief overview of the long-lived radionuclide separation processes developed in France in connection with the SPIN program

International Nuclear Information System (INIS)

Madic, C.; Bourges, J.; Dozol, J.F.

1995-01-01

To reduce the long-term potential hazards associated with the management of nuclear wastes generated by nuclear fuel reprocessing, one alternative is the transmutation of long-lived radionuclides into short-lived radionuclides by nuclear means (P ampersand T strategy). In this context, according to the law passed by the French Parliament on 30 December 1991, the CEA launched the SPIN program for the design of long-lived radionuclide separation and nuclear incineration processes. The research in progress to define separation processes focused mainly on the minor actinides (neptunium, americium and curium) and some fission products, like cesium and technetium. To separate these long-lived radionuclides, two strategies were developed. The first involves research on new operating conditions for improving the PUREX fuel reprocessing technology. This approach concerns the elements neptunium and technetium (iodine and zirconium can also be considered). The second strategy involves the design of new processes; DIAMEX for the co-extraction of minor actinides from the high-level liquid waste leaving the PUREX process, An(III)/Ln(III) separation using tripyridyltriazine derivatives or picolinamide extracting agents; SESAME for the selective separation of americium after its oxidation to Am(IV) or Am(VI) in the presence of a heteropolytungstate ligand, and Cs extraction using a new class of extracting agents, calixarenes, which exhibit exceptional Cs separation properties, especially in the presence of sodium ion. This lecture focuses on the latest achievements in these research areas

Brief overview of the long-lived radionuclide separation processes developed in france in connection with the spin program

Science.gov (United States)

Madic, Charles; Bourges, Jacques; Dozol, Jean-François

1995-09-01

To reduce the long-term potential hazards associated with the management of nuclear wastes generated by nuclear fuel reprocessing, one alternative is the transmutation of long-lived radionuclides into short-lived radionuclides by nuclear means (P & T strategy). In this context, according to the law passed by the French Parliament on 30 December 1991, the CEA launched the SPIN program for the design of long-lived radionuclide separation and nuclear incineration processes. The research in progress to define separation processes focused mainly on the minor actinides (neptunium, americium and curium) and some fission products, like cesium and technetium. To separate these long-lived radionuclides, two strategies were developed. The first involves research on new operating conditions for improving the PUREX fuel reprocessing technology. This approach concerns the elements neptunium and technetium (iodine and zirconium can also be considered). The second strategy involves the design of new processes; DIAMEX for the co-extraction of minor actinides from the high-level liquid waste leaving the PUREX process, An(III)/Ln(III) separation using tripyridyltriazine derivatives or picolinamide extracting agents; SESAME for the selective separation of americium after its oxidation to Am(IV) or Am(VI) in the presence of a heteropolytungstate ligand, and Cs extraction using a new class of extracting agents, calixarenes, which exhibit exceptional Cs separation properties, especially in the presence of sodium ion. This lecture focuses on the latest achievements in these research areas.

Brief overview of the long-lived radionuclide separation processes developed in France in connection with the SPIN program

Energy Technology Data Exchange (ETDEWEB)

Madic, C.; Bourges, J. [DRDD, Fontenay-aux-Roses (France); Dozol, J.F. [DESD, Cadarache (France)

1995-10-01

To reduce the long-term potential hazards associated with the management of nuclear wastes generated by nuclear fuel reprocessing, one alternative is the transmutation of long-lived radionuclides into short-lived radionuclides by nuclear means (P & T strategy). In this context, according to the law passed by the French Parliament on 30 December 1991, the CEA launched the SPIN program for the design of long-lived radionuclide separation and nuclear incineration processes. The research in progress to define separation processes focused mainly on the minor actinides (neptunium, americium and curium) and some fission products, like cesium and technetium. To separate these long-lived radionuclides, two strategies were developed. The first involves research on new operating conditions for improving the PUREX fuel reprocessing technology. This approach concerns the elements neptunium and technetium (iodine and zirconium can also be considered). The second strategy involves the design of new processes; DIAMEX for the co-extraction of minor actinides from the high-level liquid waste leaving the PUREX process, An(III)/Ln(III) separation using tripyridyltriazine derivatives or picolinamide extracting agents; SESAME for the selective separation of americium after its oxidation to Am(IV) or Am(VI) in the presence of a heteropolytungstate ligand, and Cs extraction using a new class of extracting agents, calixarenes, which exhibit exceptional Cs separation properties, especially in the presence of sodium ion. This lecture focuses on the latest achievements in these research areas.

Utility of reversed phase high performance liquid chromatography for on-line yield determination of radiochemical separations: Studies with cobalt

International Nuclear Information System (INIS)

Subramanian, S.; Woittiez, J.R.W.

1993-01-01

This article indicates the potentials of high performance liquid chromatography (HPLC) as a radiochemical technique for multielement separation of neutron irradiated samples. The focus lies on the convenience to use the detector signal of the eluted components to indicate the chemical yield of the analyte, which has often proved to be a crucial step in radiochemical separations. Two signals have been utilized. The UV signal of the metal-ligand complexes separated by reversed phase HPLC and the radioactive response as a result of sample irradiation of carrier-tracer addition. Change in ratio is discussed between the two signals, if any, for a specific sample. Losses of metal as much as 65% were simulated and corrected using the individual UV response. The method promises improved accuracy for elemental analysis despite losses suffered during the various chemical steps. The procedure omits the necessity of additional analytical steps for yield determination. The present article aims at the chromatographic part of the study. Cobalt as cobalt diethyldithiocarbamate has been used to demonstrate the viability of the concept. The separation was developed on c C18 reverse phase analytical column and optimized on a semi preparative one

Separation of radionuclides from spent decontamination solutions and/or evaporator concentrates

International Nuclear Information System (INIS)

Sebesta, F.; John, J.; Rosikova, K.; Motl, A.

1999-01-01

Separation of radionuclides from spent alkaline decontamination solutions has been tested in model experiments with strontium separation from simulant solution. The composite absorbers tested included TiO-PAN and NaTiO-PAN materials (titanium dioxide or sodium titanate incorporated into a matrix of polyacrylonitrile binder). As an alkaline simulant, solution of 1 M NaOH + 1 M NaNO 3 + 10 -4 M Ca(NO 3 ) 2 + 10 -5 M Sr(NO 3 ) 2 spiked with a carrier-free 85 Sr tracer, was used. The experiments were performed at a flow rate of 12.5 BV/hr. Some experiments with real and simulant spent decontamination solutions are described

Production of Cobalt-57 from irradiation of proton beams on nickel at CV-28 cyclotron of IPEN-CNEN/SP

International Nuclear Information System (INIS)

Santos, Liliane Landini Mota; Osso Junior, Joao Alberto

1996-01-01

The 57 Co is produced at the Cyclotron of IPEN-CNEN/SP through the irradiation of natural Nickel with a protons beam of 24 MeV energy. The aim of this work was to measure the thick target production yield of 57 Co and of its principal radionuclide impurities and the determination of the excitation functions of the nuclear reactions on Ni, to evaluate the best conditions for the 57 Co production. The technique used was of the stacked-foil, of Ni, Cu and Al, being the two latter utilized as current and energy monitors of the protons beam, respectively. The thick target production yield of 57 Co, through the somatory of indirect and direct reaction, 11,31 days after E.O.B., was 905,76 kBq/μA.h (24,48 μCi/μA.h) and only by indirect reaction was 174,64 kBq/μA.h (4,72 μCi/μA.h). (author)

National Low-Level Waste Management Program Radionuclide Report Series: Volume 12, Cobalt-60

International Nuclear Information System (INIS)

Adams, J.P.

1995-06-01

This report outlines the basic radiological and chemical characteristics of cobalt-60 ( 60 Co) and examines how these characteristics affect the behavior of 60 Co in various environmental media, such as soils, groundwater, plants, animals, the atmosphere, and the human body. Discussions also include methods of 60 Co production, waste types, and waste forms that contain 60 Co. All cobalt atoms contain 27 protons (Z = 27) and various numbers of neutrons (typically N = 27 to 37 neutrons) within the atom's nucleus. There is only one stable isotope of cobalt, namely 59 Co. All other cobalt isotopes, including 60 Co, are radioactive. The radioactive isotopes of cobalt have half-lives ranging from less than a second ( 54 Co-0.19 s) to 5.2 years ( 60 Co). The radioactive isotopes of cobalt are not a normal constituent of the natural environment and are generated as a result of human activities. The primary source of 60 Co in the environment has been low-level radioactive waste material generated as a result of neutron activation of stable 59 Co that is present in the structural components of nuclear reactor vessels. This isotope is also intentionally produced, usually in reactors but also to some degree in accelerators for industrial and medical uses, such as for radiation sources for cancer treatment and nondestructive testing of metals and welds. 60 Co may enter the environment as a result of the activities associated with nuclear reactor operations and decommissioning and when industrial and medical sources are being used, manufactured, or disposed

57Co and 109Cd production study in cyclotron

International Nuclear Information System (INIS)

Landini, Liliane

2000-01-01

The main objective of this work was the detailed study of all parameters involved in the production of 57 Co through the irradiation of natural Ni ( nat Ni) with a proton beam of the CV-28 Cyclotron at IPEN-CNEN/SP. The excitation functions of these reactions were measured by the stacked foil technique and were compared with literature values and those generated by the ALICE code. The results showed a good agreement with the experimental values measured for the radioisotopes: 55 Co, 56 Co, 57 Co, 58 Co, 56 Ni and 57 Ni . Thick target yields for these radioisotopes were measured, and the mean values were (346.69±203.50)kBq/μA.h, for the direct production of 57 Co and (150.59±29.60)kBq/μA.h, through the decay of 57 Ni (11,31 days after EOB - End of Bombardment). A solution of 57 CoC 2 was prepared, to fill a flood source for calibration of gamma camera, with activity of 222 MBq (6mCi) of 57 Co and impurity levels of 1.13 and 1.29% for 56 Co and 58 Co, respectively, at delivery time. In order to achieve these results, a chemical separation method was developed with a separation yield of 93% for 57 Co and a negligible loss of Ni. A composite target of Ni and Ag was prepared and a chemical separation method proposed to allow the separation between the targets and the products of interest, 57 Co and 109 Cd. The yields obtained in the irradiation of the composite target were: (947.94±239.39)kBq/μA.h of 57 Co - direct reaction, (259.00±35.15)kBq/μA.h of 57 Co - indirect reaction (11,31 days after EOB) and (71.41±5.55)kBq/μA.h of 109 Cd, which showed the efficiency of its use, as well as the chemical separation, with a yield of 80% for 57 Co and 109 Cd. The best conditions for the production of 57 Co, with the least level of radionuclidic impurities was the use of the indirect reaction, and performing the chemical separation 2 hours after EOB and a decay time of 11.31 days for the separation of 57 Co. (author)

Cobalt uptake and binding in human red blood cells

DEFF Research Database (Denmark)

Simonsen, Lars Ole; Brown, Anthony M; Harbak, Henrik

2011-01-01

of cobalt, and also from the initial slope of the cobalt buffering curve. The cobalt accumulation is similar in fed and ATP-depleted cells. The buffering curve for [Co(T)](c) can be fitted by a Michaelis type function with B(max)=24 mmol (l cells)(-1) and half-saturation at 240 µM [Co(2+)](c). The tracer...... reversibly bound, being releasable by excess extracellular EGTA in the presence of A23187, and partly tightly bound, remaining in the cells even at high ionophore concentrations. The tightly bound fraction builds up over time, and is larger and develops earlier in fed cells compared to ATP-depleted cells......-migrate with hemoglobin in Sephadex column chromatography of a lysate of (57)Co-loaded cells. (57)Co also co-migrates with hemoglobin when added to a lysate of unlabeled cells or to a solution of purified hemoglobin, in both cases with a time-dependent development of tight binding. Cobalt is known to bind to the globin...

National Low-Level Waste Management Program Radionuclide Report Series: Volume 12, Cobalt-60

Energy Technology Data Exchange (ETDEWEB)

Adams, J.P.

1995-06-01

This report outlines the basic radiological and chemical characteristics of cobalt-60 ({sup 60}Co) and examines how these characteristics affect the behavior of {sup 60}Co in various environmental media, such as soils, groundwater, plants, animals, the atmosphere, and the human body. Discussions also include methods of {sup 60}Co production, waste types, and waste forms that contain {sup 60}Co. All cobalt atoms contain 27 protons (Z = 27) and various numbers of neutrons (typically N = 27 to 37 neutrons) within the atom`s nucleus. There is only one stable isotope of cobalt, namely {sup 59}Co. All other cobalt isotopes, including {sup 60}Co, are radioactive. The radioactive isotopes of cobalt have half-lives ranging from less than a second ({sup 54}Co-0.19 s) to 5.2 years ({sup 60}Co). The radioactive isotopes of cobalt are not a normal constituent of the natural environment and are generated as a result of human activities. The primary source of {sup 60}Co in the environment has been low-level radioactive waste material generated as a result of neutron activation of stable {sup 59}Co that is present in the structural components of nuclear reactor vessels. This isotope is also intentionally produced, usually in reactors but also to some degree in accelerators for industrial and medical uses, such as for radiation sources for cancer treatment and nondestructive testing of metals and welds. {sup 60}Co may enter the environment as a result of the activities associated with nuclear reactor operations and decommissioning and when industrial and medical sources are being used, manufactured, or disposed.

Leachability of radionuclides from cement solidified waste forms produced at operating nuclear power plants

International Nuclear Information System (INIS)

Croney, S.T.

1985-03-01

This study determined the leachability indexes of radionuclides contained in solidified liquid wastes from operating nuclear power plants. Different sizes of samples of cement-solidified liquid wastes were collected from two nuclear power plants - a pressurized water reactor and a boiling water reactor - to correlate radionuclide leaching from small- and full-sized (55-gallon) waste forms. Diffusion-based model analysis (ANS 16.1) of measured radionuclide leach data from both small- and full-sized samples was performed and indicate that leach data from small samples can be used to determine leachability indexes for full-sizes waste forms. The leachability indexes for cesium, strontium, and cobalt isotopes were determined for waste samples from both plants according to the models used for ANS 16.1. The leachability indexes for the pressurized water reactor samples were 6.4 for cesium, 7.1 for strontium, and 10.4 for cobalt. Leachability indexes for the boiling water reactor samples were 6.5 for cesium, 8.6 for strontium, and 11.1 for cobalt

Extraction behavior of radionuclides in the first separation cycle in reprocessing

International Nuclear Information System (INIS)

Uchiyama, Gunzo; Asakura, Toshihide; Hotoku, Shinobu; Watanabe, Makio; Fujine, Sachio; Nemoto, Hideyuki.

1997-01-01

The chemical flowsheet experiment by using three mixer-settlers was conducted to study the extraction behavior of radionuclides such as technetium, neptunium, iodine, zirconium and ruthenium in the uranium-TBP-nitric acid solution system in the simulated first separation cycle in current reprocessing plants. The following results were obtained: More than 99.999% of the total uranium fed to the co-decontamination step in the simulated dissolver solution was extracted by TBP solvent. About 90% of the total uranium was recovered in the uranium back-extraction step. About 30% of the total neptunium fed to the co-decontamination step was in the raffinate solution in the co-decontamination step, 12% of the total neptunium was in the Tc solution in the Tc separation step and about 58% of the total neptunium was in the Pu solution in the U/Pu partitioning step. As for technetium, about 99% of the total technetium was extracted by TBP in the co-decontamination step, 86% of the total technetium was scrubbed with high acid nitric acid solution in the Tc separation step and 13% of the total technetium was in the Pu solution in the U/Pu partitioning step. As for the other radionuclides, 99% of the total ruthenium and 93% of the total zirconium were distributed into the raffinate in the co-decontamination step. In the Tc separation step, ruthenium was scrubbed more effectively than ruthenium with high acid solution. About 45% of the total iodine fed to the co-decontamination step was vaporized during the experiment. Iodine in aqueous solutions in the flowsheet was mainly in volatile I 2 form. Iodine was rarely distributed into the aqueous solution and was distributed with TBP solvent in the flowsheet. Significant amounts of iodine was contained in the washed solvent. (author)

Radiotracer studies on radionuclide and trace element cycling in corals

International Nuclear Information System (INIS)

Fowler, S.W.; Teyssie, J.L.; Acosta, A.; Gattuso, J.P.; Jaubert, J.

1999-01-01

Microcosm experiments were designed in which microcolonies of three coral species were exposed to gamma-emitting radiotracers of trace metals and radionuclides ( 110 Am, 109 Cd. 57 Cocyanocobalamin, 110 Ag, 134 Cs, 65 Zn, 60 Co, 75 Se, 85 Sr, 133 Ba, 54 Mn) to determine uptake and loss as well as distribution in tissue, skeleton and zooxanthellae. Following a seven day exposure in seawater, the degree of uptake (CF = concentration factor) for a given element was highly dependent on species. The highest CF s , in whole colonies were found for 100m Ag(82-172), 57 Co (68-124) and 65 Zn (41-52); the lowest CF s , were noted for the soluble radionuclides Cs (1-2) and Sr (2-9). Low CF s , were recorded in skeleton and increased by roughly an order of magnitude between skeleton, tissue and zooxanthellae. 241 Am is readily taken up by dead skeleton (CF=31-49), whereas in living corals it is preferentially accumulated by the tissue (CF=51-120) which acts as a partial barrier against contamination of the internal skeleton (CF=6-10). The chemical species of the element can also affect uptake by corals, as evidenced by the order of magnitude greater bioaccumulation of organic cobalt compared to the inorganic form in tissues. Once accumulated, some of the elements tested (e.g. Cd, Co) are strongly retained with biological half-lives as long as several months

Flotation-separation and ICP-AES determination of ultra trace amounts of copper, cadmium, nickel and cobalt using 2-aminocyclopentene-1-dithiocarboxylic acid.

Science.gov (United States)

Shamsipur, Mojtaba; Hashemi, Omid Reza; Safavi, Afsaneh

2005-09-01

A rapid flotation method for separation and enrichment of ultra trace amounts of copper(II), cadmium(II), nickel(II) and cobalt(II) ions from water samples is established. At pH 6.5 and with sodium dodecylsulfate used as a foaming reagent, Cu2+, Cd2+, Ni2+ and Co2+ were separated simultaneously with 2-aminocyclopentene-1-dithiocarboxylic acid (ACDA) added to 1 l of aqueous solution. The proposed procedure of preconcentration is applied prior to the determination of these four analytes using inductivity coupled plasma-atomic emission spectrometry (ICP-AES). The effects of pH, concentration of ACDA, applicability of different surfactants and foreign ions on the separation efficiency were investigated. The preconcentration factor of the method is 1000 and the detection limits of copper(II), cadmium(II), nickel(II) and cobalt(II) ions are 0.078, 0.075, 0.072 and 0.080 ng ml(-1), respectively.

Decontamination of radionuclides on construction materials

International Nuclear Information System (INIS)

Samuleev, P.V.; Andrews, W.S.; Creber, K.A.M.; Velicogna, D.

2013-01-01

A wide variety of materials can become contaminated by radionuclides, either from a terrorist attack or an industrial or nuclear accident. The final disposition of these materials depends, in large part, on the effectiveness of decontamination measures. This study reports on investigations into the decontamination of a selection of building materials. The aim has been to find an effective, easy-to-use and inexpensive decontamination system for radionuclides of cesium and cobalt, considering both the chemical and physical nature of these potential contaminants. The basic method investigated was surface washing, due to its ease and simplicity. In the present study, a basic decontamination formulation was modified by adding isotope-specific sequestering agents, to enhance the removal of cesium(I) and cobalt(II) from such construction materials as concrete, marble, aluminum and painted steel. Spiking solutions contained 134 Cs or 60 Co, which were prepared by neutron activation in the SLOWPOKE-2 nuclear reactor facility at the Royal Military College of Canada. Gamma spectroscopy was used to determine the decontamination efficiency. The results showed that the addition of sequestering agents generally improved the radiological decontamination. Although the washing of both cesium and cobalt from non-porous materials, such as aluminum and painted steel, achieved a 90-95 % removal, the decontamination of concrete and marble was more challenging, due to the porous nature of the materials. Nevertheless, the removal efficiency from 6-year-old concrete increased from 10 % to approximately 50 % for cobalt(II), and from 18 to 55 % for cesium(I), with the use of isotope binding agents, as opposed to a simple water wash. (author)

57 Co produced in cyclotron

International Nuclear Information System (INIS)

Landini, Liliane; Osso Junior, Joao Alberto

2000-01-01

The Cyclotron CV-28 of IPEN-CNEN/SP is a particle accelerator, used mainly in the radioisotope production, applied in 'in vivo' diagnosis in nuclear medicine. Some of them are employed in the calibration of Diagnosis equipment, such as gamma and X-rays detectors. Co-57 is an example of this application. A natural nickel foil was used as target and irradiated with proton beams of 24 MeV energy. The radioactivity analysis of the irradiated target was performed by Gamma Spectroscopy with a HPGe detector. A 259,74MBq (7,02 mCi) Co-57 source was prepared, 67 days after the last bombardment, with impurity levels of 1.13% for Co-56 and 1.29% for Co-58. The thick target yields for Co-57 and for the main radionuclidic impurities were measured, after the chemical separation of the irradiated target, extrapolated to the last EOB: 1.076 MBq (29.09 mCi)/mA.h, 0.012 MBq (0.33 mCi)/mA.h and 0.014 MBq (0.37 mCi)/mA.h, for Co-57, Co-56 and Co-58, respectively. (author)

Bioaccumulation of radionuclides in fertilized Canadian Shield lake basins

International Nuclear Information System (INIS)

Bird, G.A.; Schwartz, W.J.; Hesslein, R.H.; Mills, K.H.; Turner, M.A.

1998-01-01

Radionuclide tracers of heavy metals ( 59 Fe, 60 Co, 65 Zn, 75 Se 85 Sr, 134 Cs and 203 Hg) representing potential contamination from nuclear power plants, industry and agriculture were added to separate basins of Lake 226, Experimental Lakes Area, northwestern Ontario. The two basins were part of a eutrophication experiment and differed in their trophic status; the north basin (L226N) was eutrophic whereas the south basin (L226S) was mesotrophic. Our objective was to determine the uptake of the radionuclides by biota and the effect of lake trophic status on their bioaccumulation. The trophic status of the lakes did not appear to have a marked effect on the accumulation of radionuclides by the biota. This may have been because of a mid-summer leakage of nutrients between the basins which enhanced primary production in L226S, because there is a time lag between primary production and the availability of the radionuclides to the fishes or because trophic status does not affect the uptake of at least some of these radionuclides. However, there was a tendency for faster uptake of the radionuclides in L226N by fish than L226S, but the differences were not significant. Concentrations in the biota generally decreased in the order: fathead minnow>pearl dace>tadpoles>slimy sculpin>leeches. Concentrations in biota generally decreased in the order: 65 Zn> 203 Hg> 75 Se> 134 Cs> 60 Co> 85 Sr= 59 Fe. Cobalt-60 concentrations in tadpoles were greater than in the other biota. Radionuclide concentrations in the tissues of lake whitefish indicated that uptake was predominately from food. Radionuclide concentrations were usually higher in the posterior gut, liver and kidney than in other tissues, whereas body burdens were generally high in the muscle for 75 Se, 134 Cs and 203 Hg; kidney and gut for 60 Co; and bone for 65 Zn and 75 Se. Mercury-203 burdens were also high in the bone and gut

Radionuclide arthrogram to evaluate knee prostheses loosening

International Nuclear Information System (INIS)

Ahn, U.

2009-01-01

Full text:This case is about a 78 year old lady who had 3TKRs on her left knee. The 2nd revision surgery was performed due to infection. After 6 weeks long procedure, that patient was discharged with satisfactory movement without sign of infection. 15 months after the surgery, the orthopaedic surgeon found that some pressure wave effects and pain with walking. There was no sign of infection clinically. Once X-ray could not confirm any micro-loosening, the surgeon wanted to investigate with radionuclide arthrogram for this difficult case. 40 MBq in 2mls of Calcium phytate colloid (from RADPHARM Australia) was injected into the knee joint space. 30 minutes static views revealed the tracer started to travel below the tibial component. 4 hours statics views clearly indicate the tibial component loosening also there was leakage of tracer through anterior tibial osteotomy screws into the level of ankle subcutaneously. Cobalt57 flood images provided the anatomical localisation. While the surgeon was planning new component for the 3rd revision surgery, the patient's pain disappeared with time. No more revision was considered with satisfactory level of movement. This was the first and only case of radio arthogram to our department, although we perform many bone scans with same reason. On published articles, overall sensitivity and specificity are variable from 85% to 100%. When we take look at other clinical experience, there are a number of reasons in the high accuracy and reliability of radionuclide arthrogram especially for knee prosthesis loosening. Therefore I want to emphasise the benefit of radionuclide arthrogram for both patient and surgeon as a reliable diagnosis with minimum discomfort.

Methods for measuring cutaneous transfer of radionuclides through a damaged or undamaged epidermis - Application to radiotoxicology; Methodes de mesure du transfert cutane des radionucleides au travers d'un epiderme intact ou lese, application a la radiotoxicologie

Energy Technology Data Exchange (ETDEWEB)

Tymen, H. [Service de protection radiologique des armees, Clamart (France); Rateau, G.; Guillet, K.; Ramounet-Le Gall, B. [Lab. de Radiotoxicologie, Commissariat a l' Energie Atomique, CEA, Bruyeres le Chatel (France); Gerasimo, P. [Service de protection radiologique des armees, Clamart (France); Fritsch, P. [Lab. de Radiotoxicologie, Commissariat a l' Energie Atomique, CEA, Bruyeres le Chatel (France)

2002-07-01

Although skin contamination by radionuclides is the most common cause of nuclear workers accidents, few studies dealing with the penetration of radioactive contamination through the skin are available. This work is a review of experimental methods that allow to assess transfer of radionuclides through the skin in occupational conditions, with or without skin trauma. The first section describes the different methods applied for skin transfer assessment of chemicals used in pharmacology. Major radionuclide contamination accidents can be associated with skin traumas. Thus, the second section describes the adaptation of these methods to radiotoxicology. Finally, the third section is an in vivo investigation of cobalt transfer ({sup 57}CoCl{sub 2}) through undamaged and damaged skin which simulates different industrial accident conditions (excoriation, acid or alcalin burn, scalding, branding). (author)

Radionuclide generators

International Nuclear Information System (INIS)

Lambrecht, R.M.

1983-01-01

The status of radionuclide generators for chemical research and applications related to the life sciences and biomedical research are reviewed. Emphasis is placed upon convenient, efficient and rapid separation of short-lived daughter radionuclides in a chemical form suitable for use without further chemical manipulation. The focus is on the production of the parent, the radiochemistry associated with processing the parent and daughter, the selection and the characteristic separation methods, and yields. Quality control considerations are briefly noted. The scope of this review includes selected references to applications of radionuclide generators in radiopharmaceutical chemistry, and the life sciences, particularly in diagnostic and therapeutic medicine. The 99 Mo-sup(99m)Tc generator was excluded. 202 references are cited. (orig.)

Speciation analysis of cobalt in foods by high-performance liquid chromatography and neutron activation analysis

International Nuclear Information System (INIS)

Muto, Toshio; Koyama, Motoko

1994-01-01

A combined method by coupling high-performance liquid chromatography (HPLC, as a separation method) with neutron activation analysis (as a detection method) have been applied to the speciation analysis of cobalt in daily foods (e.g. egg, fish and milk). Cobalt species including free cobalt, vitamin B 12 and protein-bound cobalt were separated with a preparative HPLC and a centrifuge. Subsequently, the determination of cobalt in the separated species was made by neutron activation analysis. The results showed that the content of the total cobalt in the foods was found to lie in the range 0.4-11ng/g(0.4-11ppb) based on wet weight. The compositions of free cobalt, vitamin B 12 and protein-bound cobalt were ranged 16-43%, 55-73%, 2.3-17%, respectively. These experimental evidences suggest that the combination of HPLC and neutron activation analysis is expected to be a useful tool for speciation analysis of trace elements in biological as well as environmental materials. (author)

Selected radionuclides important to low-level radioactive waste management

International Nuclear Information System (INIS)

1996-11-01

The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237

Selected radionuclides important to low-level radioactive waste management

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237.

Valence electronic structure of cobalt phthalocyanine from an optimally tuned range-separated hybrid functional.

Science.gov (United States)

Brumboiu, Iulia Emilia; Prokopiou, Georgia; Kronik, Leeor; Brena, Barbara

2017-07-28

We analyse the valence electronic structure of cobalt phthalocyanine (CoPc) by means of optimally tuning a range-separated hybrid functional. The tuning is performed by modifying both the amount of short-range exact exchange (α) included in the hybrid functional and the range-separation parameter (γ), with two strategies employed for finding the optimal γ for each α. The influence of these two parameters on the structural, electronic, and magnetic properties of CoPc is thoroughly investigated. The electronic structure is found to be very sensitive to the amount and range in which the exact exchange is included. The electronic structure obtained using the optimal parameters is compared to gas-phase photo-electron data and GW calculations, with the unoccupied states additionally compared with inverse photo-electron spectroscopy measurements. The calculated spectrum with tuned γ, determined for the optimal value of α = 0.1, yields a very good agreement with both experimental results and with GW calculations that well-reproduce the experimental data.

Concentration of radioactive cobalt by seaweeds in the food chain

International Nuclear Information System (INIS)

Nakahara, Motokazu; Koyanagi, Taku; Saiki, Masamichi

1976-01-01

On the pathway of radioactive substances in marine environments, seaweeds play an important role because of their higher concentration factors for many radionuclides and because they constitute a link of food chain in the sea. In the present work, uptake, distribution and excretion of radioactive cobalt were studied on several kinds of seaweeds by radioisotope tracer experiments under laboratory conditions and concentration factors were calculated. The concentration factors were also estimated from the results of stable cobalt determination by activation analysis or atomic absorption spectrometry on seaweeds and seawater, and compared with the results of tracer expts. The seaweeds showed the species specificity for the concentration of stable and radioactive cobalt with diverse values of concentration factors and biological half-lives. The transfer of radioactive cobalt in the food chain from contaminated seaweeds to mollusca was examined by feeding abalones, Haliotis discus, with four kinds of seaweed labelled with 60 Co and observing retention. Absorption rate for radioactive cobalt by abalones calculated at two days after feeding showed diverse values depending upon the species of seaweed, as follows: 47% through Laminaria japonica and Ulva pertusa, 31% through Undaria pinnatifida and 26 through Eisenia bicyclis, respectively. From the results, it was assumed that the accumulation of radioactive cobalt by mollusca is affected by the species of seaweeds as food. A very high concentration of ingested radioactive cobalt in the midgut gland was seen on the autoradiograph of abalone samples. (auth.)

Concentration of radioactive cobalt by seaweeds in the food chain

International Nuclear Information System (INIS)

Nakahara, M.; Koyanagi, T.; Saiki, M.

1975-01-01

On the pathway of radioactive substances in marine environments, seaweeds play an important role because of their higher concentration factors for many radionuclides and because they constitute a link in the food chain. In the present work, uptake, distribution and excretion of radioactive cobalt were studied on several kinds of seaweeds by radioisotope tracer experiments under laboratory conditions and concentration factors were calculated. The concentration factors were also estimated from the results of stable cobalt determination by activation analysis or atomic absorption spectrometry on seaweeds and seawater, and compared with the results of tracer experiments. The seaweeds showed the species specificity for the concentration of stable and radioactive cobalt with diverse values of concentration factors and biological half-lives. The transfer of radioactive cobalt in the food chain from contaminated seaweeds to mollusca was examined by feeding abalones, Haliotis discus, with four kinds of seaweed labelled with 60 Co and observing retention. Absorption rate for radioactive cobalt by abalones calculated at two days after feeding showed diverse values depending upon the species of seaweed, as follows: 47% through Laminaria japonica and Ulva pertusa, 31% through Undaria pinnatifida and 26% through Eisenia bicyclis, respectively. From the results, it was assumed that the accumulation of radioactive cobalt by mollusca is affected by the species of seaweeds as food. A very high concentration of ingested radioactive cobalt in the midgut gland was seen on the autoradiograph of abalone samples. (author)

{sup 55}Co separation from proton irradiated metallic nickel

Energy Technology Data Exchange (ETDEWEB)

Valdovinos, H. F., E-mail: hvaldovinos@wisc.edu; Graves, S., E-mail: hvaldovinos@wisc.edu; Barnhart, T., E-mail: hvaldovinos@wisc.edu; Nickles, R. J., E-mail: hvaldovinos@wisc.edu [Department of Medical Physics, University of Wisconsin - Madison, Madison, WI (United States)

2014-11-07

{sup 55}Co with > 97% radionuclidic purity 24 hours after end of bombardment (EoB) was produced from the {sup 58}Ni(p,α) reaction using proton irradiations of 16 MeV on natural nickel. Two-hour irradiations with 25 μA on a 254 μm thick nickel foil generate 0.18 ± 0.01 GBq (n = 3) 24 hours after EoB. The separation of cobalt from the target material and other metallic contaminants present at trace levels is accomplished in HCl medium by two rounds of anion exchange chromatography (AG1-X8) using an automated module driven by a peristaltic pump. 80 ± 5 % (n = 3) of the activity generated at EoB is ready for labeling in 0.1 M HCl one hour after the start of separation. Using 99.999% pure Ni, the reactivity (decay corrected to EoB) with the bifunctional chelator (BFC) DOTA was 8.5 GBq/μmol; enough for radiolabeling BFC conjugated biomolecules at a nmol scale with > 90% yield. Using 99.9% pure Ni the reactivity with DOTA and NOTA was 0.19 +/− 0.09 GBq/μmol and 2.9 +/− 1.7 GBq/μmol (n = 2), respectively. Both cobalt complexes showed 100% in vitro stability in PBS and mouse serum over 41 hours at room temperature. MicroPET images of a miniature Derenzo phantom show excellent resolution where rods of 1.5 mm were separated by two times their diameter.

X-ray fluorescence determination of cobalt in iron-manganese oceanic concretions

International Nuclear Information System (INIS)

Ivanenko, V.V.; Kustov, V.N.; Metelev, A.Yu.; Rakita, K.A.

1989-01-01

A method was developed for resolution of weak analytical lines for elements determined by radionuclide-excited X-ray fluorescence multi-element analysis. The method was used aboart for determining cobalt and some other commercially valuable elements in iron-manganese concretions of Pacific ocean 109 Cd was used as an ionizing radiation source

A new simulation model for calculating the internal exposure of some radionuclides

Directory of Open Access Journals (Sweden)

Mahrous Ayman

2009-01-01

Full Text Available A new model based on a series of mathematical functions for estimating excretion rates following the intake of nine different radionuclides is presented in this work. The radionuclides under investigation are: cobalt, iodine, cesium, strontium, ruthenium, radium, thorium, plutonium, and uranium. The committed effective dose has been calculated by our model so as to obtain the urinary and faecal excretion rates for each radionuclide. The said model is further validated by a comparison with the widely spread Mondal software and a simulation program. The results obtained show a harmony between the Mondal package and the model we have constructed.

Electron capture Auger aftereffect of ammine cobalt complex

International Nuclear Information System (INIS)

Harada, Masayuki; Sano, Hirotoshi

1976-01-01

The study of ammine cobalt complex by luminescent Moessbauer spectrometry method was performed. The method was compared with hot atom chemistry method. The electron states in atoms are changed by the aftereffect on Auger emission following the electron capture process. The state of oxidation of disintegration products is usually higher than that of parent nuclei. However, sometimes, lower oxidation is seen in Fe-57, the daughter nuclei of Co-57. This phenomenon may be due to radiation chemistry process, and this effect can be observed by the luminescent Moessbauer spectrometry method. However, the range of the effect can not be seen by the Moessbauer method. Estimation showed that the Auger electrons stay within the surrounding area of the disintegration atom, and the effect does not reach to distant places. The yield of Fe-57 in the electron capture process of Co-57 in cobalt complex, the G-value, and the hot atom chemical yield were obtained. It is concluded that the aftereffect of the Auger process is the localized radiation chemistry effect. Good correlation was seen between the present method and the hot atom chemistry method. (Kato, T.)

Studies of the yields of 57Fe(II)-species produced after the EC-decay and of 60Co(II)-species produced in the (n, γ) reaction in cobalt(III) coordination compounds

International Nuclear Information System (INIS)

Sano, Hirotoshi; Harada, Masayuki; Endo, Kazutoyo

1978-01-01

The yields of 57 Fe(II)-species produced after EC-decay were compared with those of 60 Co(II)-species produced in the 59 Co(n, γ) 60 Co reaction for twelve cobalt(III) coordination compounds. The results indicate that the radiochemical yield of 60 Co(II)-species correlates with the yield of 57 Fe(II)-species except in the case of [Co(NH 3 ) 6 ] 2 (CrO 4 ) 3 . The anomalously low yield of 57 Fe(II)-species in [Co(NH 3 ) 6 ] 2 (CrO 4 ) 3 is ascribed to the reaction of chromate anions with ammine ligands initiated by the nuclear transformation in a solid. (author)

Microsystems for anion exchange separation of radionuclides in nitric acid media

Energy Technology Data Exchange (ETDEWEB)

Losno, M.; Brennetot, R.; Mariet, C. [DEN/Service d' Etudes Analytiques et de Reactivite des Surfaces - SEARS, CEA, Centre de Saclay, Universite Paris-Saclay, F-91191, Gif sur Yvette (France); Ferrante, I.; Descroix, S. [MMBM Group, Institut Curie Research Center, CNRS UMR 168, Paris (France)

2016-07-01

An efficient and reproducible photo-polymerized poly(ethylene glycol methacrylate methacrylate-co- allyl methacrylate) monolith was synthesized and a photo-grafting process based on the ene-thiol click-chemistry has been performed to give anion exchange properties to the monolith. Since their introduction in the early 1990's polymethacrylate monoliths have emerged as a powerful alternative for microscale separations or sample treatment. Their relatively simple implementation in columns with small internal diameters makes them particularly attractive for the new chromatographic challenges of complex matrices analysis and on-chip separations. Despite their relatively poor ion-exchange capacity due to their highly porous structure, their use as anion exchangers is of large interest for nuclear analysis as numerous separations are based on this process. This paper presents a systematic study of the synthesis of the polymeric porous monolith and the versatile and robust functionalization method developed for the specific strong acidic media used in radiochemical procedures. The robustness of the stationary phase was tested in concentrated nitric acid. It appears that the C-S bond formed via thiol-ene chemistry is strong enough to be used to graft function of interest for separation in strong nitric acid medium. The photo-grafted anion exchanger, a quaternary ammonium, presents sufficient resistance to be used for radionuclide separation in [HNO{sub 3}]=5 mol.L{sup -1}so the next step is its integration in the cyclo olefin copolymer (COC) micro-system.

Preliminary studies of cobalt complexation in groundwater

International Nuclear Information System (INIS)

Warwick, P.; Shaw, P.; Williams, G.M.; Hooker, P.J.

1988-01-01

A relatively non-invasive method has been used to separate complexed from free cobalt-60 in groundwater, using the weak cationic adsorption properties of Sephadex gels, and a mobile phase of natural groundwater. Results show the kinetics of Co complex formation in groundwater to be slow, and that the equilibrium position is affected by temperature, cobalt concentration and the ionic/organic strength of the groundwater. The addition of DAEA cellulose to the groundwater to remove humic material, also removed the majority of organic species which absorb UV at 254 nm, but 45% of the original total organic carbon remained, and the amount of complexed cobalt left in solution was only reduced to 76% of its former concentration. This suggests that the completed Co species separated by the method described in this paper are a mixture of inorganic and organic compounds, and studies are therefore continuing to establish their exact nature. (author)

Preliminary studies of cobalt complexation in groundwater

International Nuclear Information System (INIS)

Warwick, P.; Shaw, P.; Williams, G.M.; Hooker, P.J.

1988-01-01

A relatively non-invasive method has been used to separate complexed from free cobalt-60 in groundwater, using the weak cationic adsorption properties of Sephadex gels, and a mobile phase of natural groundwater. Results show the kinetics of Co complex formation in groundwater to be slow, and that the equilibrium position is affected by temperature, cobalt concentration and the ionic/organic strength of the groundwater. The addition of DEAE cellulose to the groundwater to remove humic material, also removed the majority of organic species with absorb UV at 254 nm, but 45% of the original total organic carbon remained, and the amount of complexed cobalt left in solution was only reduced to 76% of its former concentration. This suggests that the complexed Co species separated by the method described in this paper are a mixture of inorganic and organic compounds, and studies are therefore continuing to establish their exact nature. (orig.)

Moessbauer study of cobalt and iron in the cyanobacterium (blue green alga)

International Nuclear Information System (INIS)

Ambe, Shizuko

1990-01-01

Moessbauer emission and absorption studies have been performed on cobalt and iron in the cyanobacterium (blue-green alga). The Moessbauer spectrum of the cyanobacterium cultivated with 57 Co is decomposed into two doublets. The parameters of the major doublet are in good agreement with those of cyanocobalamin (vitamin B 12 ) labeled with 57 Co. The other minor doublet has parameters close to those of Fe(II) coordinated with six nitrogen atoms. These suggest that cobalt is used for the biosynthesis of vitamin B 12 or its analogs in the cyanobacterium. The spectra of the cyanobacterium grown with 57 Fe show that iron is in the high-spin trivalent state and possibly in the form of ferritin, iron storage protein. (orig.)

Cobalt adsorption/desorption on sediments from Piraquara de Fora bay, Angra dos Reis, Brazil

International Nuclear Information System (INIS)

Ferreira, Ingryd M.; Carvalho, Franciane M.; Ribeiro, Fernando C.A.; Martins, Nadia S.F.; Peres, Sueli S.; Lauria, Dejanira C.

2015-01-01

Among the radionuclides released with the liquid effluents from PWR power plants, cobalt isotopes ( 60 Co and 58 Co) play an important role for risk and environmental impact assessments. The laboratory experiments on radionuclide adsorption-desorption, followed by the use of adsorption isotherms are useful tools for prediction of transport, distribution, accumulation, and fate of a contaminant into a specific medium. Adsorption and desorption experiments were carried out in batches, using two sediment samples collected in Piraquara de Fora Bay, near the discharge channel of the liquid effluents from CNAAA. Aiming the assessment of the radioisotope adsorption mechanisms, sediment samples were shaken with solutions containing cobalt chloride which concentrations ranged between 10 -10 and 10 -3 M. In order to estimate the efficiency of adsorption, 100 Bq of 60 Co were used as radioactive tracer. The experimental data fitted well with Freundlich and Langmuir isotherms. Results point out a favorable and high cobalt adsorption on the sediments, although smaller than the ones reported in literature studies. Such smaller trend of adsorption coefficients may be caused by the low exchange capacity of the prevailing clay, kaolinite. The maximum adsorption capacities were found to be 10 and 17 moles/g for sediments in PT-01 and PT-02, respectively. Values lower than 8% of the adsorbed cobalt underwent desorption and this amount decreased to 4%, with time, which show the high retention capacity of these sediments. (author)

Excitation functions of proton-induced reactions on {sup nat}Fe and enriched {sup 57}Fe with particular reference to the production of {sup 57}Co

Energy Technology Data Exchange (ETDEWEB)

Al-Abyad, M. [Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany); Cyclotron Facility, Nuclear Research Centre, Atomic Energy Authority, Cairo 13759 (Egypt); Comsan, M.N.H. [Cyclotron Facility, Nuclear Research Centre, Atomic Energy Authority, Cairo 13759 (Egypt); Qaim, S.M. [Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany)], E-mail: s.m.qaim@fz-juelich.de

2009-01-15

Excitation functions of the reactions {sup nat}Fe(p,xn){sup 55,56,57,58}Co, {sup nat}Fe(p,x){sup 51}Cr, {sup nat}Fe(p,x){sup 54}Mn, {sup 57}Fe(p,n){sup 57}Co and {sup 57}Fe(p,{alpha}){sup 54}Mn were measured from their respective thresholds up to 18.5 MeV, with particular emphasis on data for the production of the radionuclide {sup 57}Co (T{sub 1/2}=271.8 d). The conventional stacked-foil technique was used, and the samples for irradiation were prepared by an electroplating or sedimentation process. The measured excitation curves were compared with the data available in the literature as well as with results of nuclear model calculations. From the experimental data, the theoretical yields of the investigated radionuclides were calculated as a function of the proton energy. Over the energy range E{sub p}=15{yields}5 MeV the calculated yield of {sup 57}Co from the {sup 57}Fe(p,n){sup 57}Co process amounts to 1.2 MBq/{mu}A h and from the {sup nat}Fe(p,xn){sup 57}Co reaction to 0.025 MBq/{mu}A h. The radionuclidic impurity levels are discussed. Use of highly enriched {sup 57}Fe as target material would lead to formation of high-purity {sup 57}Co.

Transfer coefficients of radionuclides secreted in milk of dairy cows

International Nuclear Information System (INIS)

Sam, D.; Williams, W.F.; Rockmann, D.D.; Allen, J.T.

1980-01-01

This study simulated experimentally the transfer of radionuclides to milk of dairy cows on a worst-case situation using various radionuclides known to emanate from nuclear power stations and which have been detected on particulates. Two lactating Holstein cows were administered orally one gelatin capsule containing 10 radionuclides in water-soluble form per day for 14 consecutive days. Milk samples were collected and aliquots analyzed in a germanium lithium-drifted detector coupled to a 2048-multichannel gamma-ray analyzer to measure small amounts of complex mixtures of radionuclides. The transfer coefficients of the radionuclides were calculated when their secretion in milk reached or approached a plateau of concentration. The radionuclides and their transfer coefficients to milk were: chromium 51 less than 0.01%; manganese 54 0.033 +- 0.005%; cobalt 60 0.01 +- 0.002%; iron 59 0.0048 +- 0.002%; zinc 65 0.31 +- 0.07%; selenium 75 0.29 +- 0.1%; antimony 125 0.011 +- 0.003%; iodine 131 0.88 +- 0.05%; and cesium 137 0.79 +- 0.08%

Effects of arctic temperatures on distribution and retention of the nuclear waste radionuclides 241Am, 57Co, and 137Cs in the bioindicator bivalve Macoma balthica

Science.gov (United States)

Hutchins, D.A.; Stupakoff, I.; Hook, S.; Luoma, S.N.; Fisher, N.S.

1998-01-01

The disposal of radioactive wastes in Arctic seas has made it important to understand the processes affecting the accumulation of radionuclides in food webs in coldwater ecosystems. We examined the effects of temperature on radionuclide assimilation and retention by the bioindicator bivalve Macoma balthica using three representative nuclear waste components, 241Am, 57Co, and 137Cs. Experiments were designed to determine the kinetics of processes that control uptake from food and water, as well as kinetic constants of loss. 137Cs was not accumulated in soft tissue from water during short exposures, and was rapidly lost from shell with no thermal dependence. No effects of temperature on 57Co assimilation or retention from food were observed. The only substantial effect of polar temperatures was that on the assimilation efficiency of 241Am from food, where 10% was assimilated at 2??C and 26% at 12??C. For all three radionuclides, body distributions were correlated with source, with most radioactivity obtained from water found in the shell and food in the soft tissues. These results suggest that in general Arctic conditions had relatively small effects on the biological processes which influence the bioaccumulation of radioactive wastes, and bivalve concentration factors may not be appreciably different between polar and temperate waters.

Cobalt

Science.gov (United States)

Slack, John F.; Kimball, Bryn E.; Shedd, Kim B.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Cobalt is a silvery gray metal that has diverse uses based on certain key properties, including ferromagnetism, hardness and wear-resistance when alloyed with other metals, low thermal and electrical conductivity, high melting point, multiple valences, and production of intense blue colors when combined with silica. Cobalt is used mostly in cathodes in rechargeable batteries and in superalloys for turbine engines in jet aircraft. Annual global cobalt consumption was approximately 75,000 metric tons in 2011; China, Japan, and the United States (in order of consumption amount) were the top three cobalt-consuming countries. In 2011, approximately 109,000 metric tons of recoverable cobalt was produced in ores, concentrates, and intermediate products from cobalt, copper, nickel, platinum-group-element (PGE), and zinc operations. The Democratic Republic of the Congo (Congo [Kinshasa]) was the principal source of mined cobalt globally (55 percent). The United States produced a negligible amount of byproduct cobalt as an intermediate product from a PGE mining and refining operation in southeastern Montana; no U.S. production was from mines in which cobalt was the principal commodity. China was the leading refiner of cobalt, and much of its production came from cobalt ores, concentrates, and partially refined materials imported from Congo (Kinshasa).The mineralogy of cobalt deposits is diverse and includes both primary (hypogene) and secondary (supergene) phases. Principal terrestrial (land-based) deposit types, which represent most of world’s cobalt mine production, include primary magmatic Ni-Cu(-Co-PGE) sulfides, primary and secondary stratiform sediment-hosted Cu-Co sulfides and oxides, and secondary Ni-Co laterites. Seven additional terrestrial deposit types are described in this chapter. The total terrestrial cobalt resource (reserves plus other resources) plus past production, where available, is calculated to be 25.5 million metric tons. Additional resources of

Assessment of cobalt 57 tagged bleomycin as a clinical aid in staging of head and neck carcinoma

International Nuclear Information System (INIS)

Cummings, C.W.; Larson, S.M.; Dobie, R.A.; Weymuller, E.A. Jr.; Rudd, T.G.; Merello, A.

1981-01-01

Critical assessment of head and neck cancer with respect to staging has, on occasion, been disappointingly ineffective. We have attempted to correlate the incidence of measureable uptake of cobalt 57 tagged bleomycin by primary squamous cell carcinoma and metastatic cervical lymph nodes. Forty-six cases have been evaluated with respect to histopathological confirmation of the suspected metastatic disease. We have found that this diagnostic measure increases our acumen in staging of head and neck cancer. The relevance of the Co-Bleo scans as a diagnostic aid is reported in 46 cases. Malignant tumors greater than 2 cm in size appear to demonstrate active uptake of the imaging agent. Small tumor size and excess background radioactivity contribute to the false-negatives (17%). Inflammatory conditions or benign tumors of the salivary apparatus may result in minimal uptake, thus, a false-positive result (10%). An increase in the radioactivity of the Co-Bleo may enhance the benefits of this procedure in the search for an undiagnosed primary, as well as undiagnosed local or distant metastases

Assessment of cobalt 57 tagged bleomycin as a clinical aid in staging of head and neck carcinoma

International Nuclear Information System (INIS)

Cummings, C.W.; Larson, S.M.; Dobie, R.A.; Weymuller, E.A. Jr.; Rudd, T.G.; Merello, A.

1981-01-01

Critical assessment of head and neck cancer with respect to staging has, on occasion, been disappointingly ineffective. The incidence of measurable uptake of cobalt 57 tagged bleomycin by primary squamous cell carcinoma and metastatic cervical lymph nodes has been correlated. Forty-six cases have been evaluated with respect to histopathological confirmation of the suspected metastatic disease. We have found that this diagnostic measure increases our acumen in staging of head and neck cancer. The relevance of the Co-Bleo scans as a diagnostic aid is reported in 46 cases. Malignant tumors greater than 2 cm in size appear to demonstrate active uptake of the imaging agent. Small tumor size and excess background radioactivity contribute to the false-negatives (17%). Inflammatory conditions or benign tumors of the salivary apparatus may result in minimal uptake, thus, a false-positive result (10%). An increase in the radioactivity of the Co-Bleo may enhance the benefits of this procedure in the search for an undiagnosed primary, as well as undiagnosed local or distant metastases

Removal of radionuclides from liquid streams by reverse osmosis

International Nuclear Information System (INIS)

Deshmukh, U.A.; Ramachandhran, V.; Misra, B.M.

1987-01-01

Separation of radionuclides in trace concentrations by cellulose acetate membranes has been under investigation in this laboratory, and the behaviour of some important radionuclides such as 137 Cs and 90 Sr under reverse osmosis has been reported earlier. The present work deals with a few other typical radionuclides such as 60 Co, 103 Ru and 131 I which are not fully amenable to conventional methods for their removal. Separation of these radionuclides from liquid streams by the reverse osmosis process was studied using a small reverse osmosis test cell. Various parameters like membrane porosity, applied pressure and feed activity levels were investigated. Cellulose acetate membranes offer reasonable separation of 60 Co, 103 Ru and 131 I radionuclides, indicating the potential of reverse osmosis for treatment of effluents containing these radioisotopes. The percent separation is found to be in the order of Co > Ru > I. The percent radioactive separation improves with increases in feed activity. The performance data are explained in terms of solution-diffusion mechanism. It appears that the separation of radionuclides is not governed by diffusion alone, but by the interaction of solutes with the membranes. (author)

Analysis of radioactive cobalt

International Nuclear Information System (INIS)

1977-01-01

This is a manual published by Science and Technology Agency, Japan, which prescribes on the analysis method for radioactive cobalt which is a typical indexing nuclide among the radioactive nuclides released from nuclear facilities. Since the released cobalt is mainly discharged to coastal region together with waste water, this manual is written for samples of sea water, sea bottom sediments and marine organisms. Radioactive cobalt includes the nuclides of 57 co, 58 Co, 60 Co, etc., the manual deals with them as a whole as 60 Co of long half life. Though 60 Co analysis has become feasible comparatively simply due to scintillation or semi-conductor spectrometry, trace 60 Co analysis is performed quantitatively by co-precipitation or collection into alumina and scintillation spectrometry. However, specific collecting operation and γ-γ coincidence measurement have been required so far. This manual employs 60 Co collection by means of ion-exchange method and measurement with low background GM counting system, to analyze quantitatively and rapidly low level 60 Co. It is primarily established as the standard analyzing method for the survey by local autonomous bodies. It is divided into 4 chapters including introduction sea water, marine organisms, and sea bottom sediments. List of required reagents is added in appendix. (Wakatsuki, Y.)

Contribution to freshwater hydro systems multi pollution study: experimental study of metallic and organic micro-pollutants on radionuclides bioaccumulation by fish

International Nuclear Information System (INIS)

Ausseil, O.

2001-07-01

The influence of some metallic (cadmium, zinc) and organic (17 β-oestradiol, atrazine, polychlorinated biphenyls, polycyclic aromatic hydrocarbons) pollutants on artificial radionuclide ( 110m Ag, 134 Cs 57 Co) bioaccumulation characteristics by rainbow trout (Oncorhynchus mykiss) has been tested. The basic hypothesis of this work assume that the organisms' exposure to pollutants induces mechanisms of response which could modify radionuclides bioaccumulation characteristics. During the experiments, some biological and biochemical (bio-markers) analyses were performed in order to characterize the nature and the intensity of induced stress in the organisms. These experiments were performed in field and in laboratory. The results show that a cadmium and zinc exposure leads to the induction of systems against oxidative stress or systems implied in metal sequestration. It also leads to a strong reduction of 110m Ag (- 60 %) and 134 Cs (- 33 %) bioaccumulation. No effect has been observed on 57 Co bioaccumulation. For all tested organic compounds except for fluoranthene, exposure leads to an increase of radioactive caesium ( + 10 to 45 %) and cobalt (+ 30 to 60 %) quantities bio-accumulated by rainbow trout. Only 17 β-oestradiol exposure leads to an increase of 110m Ag uptake by rainbow trout. Some hypothesis concerning the involved mechanisms are proposed, and the main implications of this work in operational radioecology are discussed. (author)

Quantitative radionuclide angiocardiography

International Nuclear Information System (INIS)

Scholz, P.M.; Rerych, S.K.; Moran, J.F.; Newman, G.E.; Douglas, J.M.; Sabiston, D.C. Jr.; Jones, R.H.

1980-01-01

This study introduces a new method for calculating actual left ventricular volumes and cardiac output from data recorded during a single transit of a radionuclide bolus through the heart, and describes in detail current radionuclide angiocardiography methodology. A group of 64 healthy adults with a wide age range were studied to define the normal range of hemodynamic parameters determined by the technique. Radionuclide angiocardiograms were performed in patients undergoing cardiac catherization to validate the measurements. In 33 patients studied by both techniques on the same day, a close correlation was documented for measurement of ejection fraction and end-diastolic volume. To validate the method of volumetric cardiac output calcuation, 33 simultaneous radionuclide and indocyanine green dye determinations of cardiac output were performed in 18 normal young adults. These independent comparisons of radionuclide measurements with two separate methods document that initial transit radionuclide angiocardiography accurately assesses left ventricular function

Separation of radionuclides using host-guest materials

International Nuclear Information System (INIS)

Drabova, V.

2014-01-01

This thesis is focused on the development of complex procedure with using commercially available sorbents to separate anthropogenic actinides 237 Np, 241 Am, 238 Pu and 239 , 240 Pu and their determination in the liquid radioactive wastes by using alpha spectrometry. Abilities of using commercially available sorbent AnaLig(R)Pu-02 gel from IBC Advanced Technologies, Inc. were tested, this product belongs to host-guest materials based on molecular recognition technology. This material is capable of selectively capturing actinides in oxidation state IV. To adjust the oxidation state of 238 Pu and 239 , 240 Pu was used NaNO 2 . Pu(IV) forms in the medium of nitric acid complexes, [Np(NO 3 ) 6 ] - , which are captured on the column. For the second monitored radionuclide, neptunium is typical valence V, Np(V) in the concentrated nitric acid produces strong complexes, [Np(NO 3 ) 6 ] - , which are capable of the sorption on the column of AnaLig(R)Pu-02 gel. The most common state of americium in aqueous solutions is III. Whereas in this oxidation state, americium do not form complexes in 8 mol·dm -3 nitric acid is the result of the flow-through. On the base of experimental obtained results, solution of 0.1 mol·dm -3 NH 4 I in 9 mol·dm -3 HCl was selected for elution of plutonium. Neptunium was eluted from the column using 9 mol·dm -3 of HCl with addition of 0.5 cm 3 TiCl 3 . Optimizing conditions for the separation procedure was performed by using model solution of radioactive waste which was prepared according to the chemical composition of radioactive concentrate from NPP Mochovce and NPP Bohunice. The effect of the concentration of Fe 3+ , the effect of the concentration of the HCl, the effect of the concentration of the solution of NH 4 I and the effect of the volume of this solution to the yields of 238 Pu were studied. And also was studied the effect of 9 mol·dm -3 of HCl and the effect of volume of 15 % TiCl 3 to the yields of 237 Np. Sorbent DGA(R) Resin from

Applicability of alkali activated slag-seeded Egyptian Sinai kaolin for the immobilization of 60Co radionuclide

International Nuclear Information System (INIS)

El-Naggar, M.R.

2014-01-01

The present work was established to determine the applicability of local Egyptian kaolinite and blast furnace slag (BFS) as raw materials toward the synthesis of geopolymers and subsequent immobilization of cobalt-60, which is one of the most abundant radionuclides generated in radioactive waste streams in Egypt. XRF, XRD, FT-IR, and SEM techniques were used to characterize the local raw materials and their corresponding alkali activated products. Metakaolin (MK) was obtained by thermal treatment of Egyptian Sinai kaolin 750 °C/4 h. MK and five different BFS content (5, 10, 30, 50 and 80%) were used to synthesize geopolymeric matrices using an alkaline activator of Si-modulus = 1.35 at solid/liquid ratios of 0.8. Compressive strength tests were performed indicating that 50% BFS addition gave the highest values of compressive strength. The IAEA standard leaching tests of cobalt-60 from the solidified waste matrices were carried out. The effective diffusion coefficients of cobalt-60 radionuclides from the solidified waste matrices were calculated to be in the order of 10 −14 cm 2 /s. Leaching of radionuclides was examined to be controlled by the wash-off mechanism with very acceptable values. These results gave encouragement that the tested Egyptian raw materials can be conveniently applied for the synthesis of geopolymers that can be used as a low-cost and high-efficiency materials for the immobilization of radioactive waste

After-Effects of the Cobalt-57-Iron-57 Electron-Capture Reaction in Hexacyanocobaltate (III) Complexes

DEFF Research Database (Denmark)

Fenger, Jørgen Folkvard; Siekierska, K.E.; Olsen, J.

1973-01-01

Isomorphous hexacyanocobaltate(III) complexes with the bivalent metal cations Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ have been labelled with 57Co and used as Mössbauer sources. Whilst the spectrum of the complex Fe3[57Co(CN)6]2 can be resolved into a single line corresponding to the ion Fe II...

Radionuclide diagnosis of emergency states

International Nuclear Information System (INIS)

Ishmukhametov, A.I.

1985-01-01

Solution of emergency state radionuclide diagnostics from the technical point of view is provided by the application of the mobile quick-operating equipment in combination with computers, by the use of radionuclides with acceptable for emergency medicine characteristics and by development of radionuclide investigation data propcessing express-method. Medical developments include the study of acute disease and injury radioisotope semiotics, different indication diagnostic value determining, comparison of the results, obtained during radionuclide investigation, with clinicolaboratory and instrumental data, separation of methodical complex series

Sensors and Automated Analyzers for Radionuclides

International Nuclear Information System (INIS)

Grate, Jay W.; Egorov, Oleg B.

2003-01-01

The production of nuclear weapons materials has generated large quantities of nuclear waste and significant environmental contamination. We have developed new, rapid, automated methods for determination of radionuclides using sequential injection methodologies to automate extraction chromatographic separations, with on-line flow-through scintillation counting for real time detection. This work has progressed in two main areas: radionuclide sensors for water monitoring and automated radiochemical analyzers for monitoring nuclear waste processing operations. Radionuclide sensors have been developed that collect and concentrate radionuclides in preconcentrating minicolumns with dual functionality: chemical selectivity for radionuclide capture and scintillation for signal output. These sensors can detect pertechnetate to below regulatory levels and have been engineered into a prototype for field testing. A fully automated process monitor has been developed for total technetium in nuclear waste streams. This instrument performs sample acidification, speciation adjustment, separation and detection in fifteen minutes or less

Treatment of heavy metals and radionuclides in groundwater and wastewater by magnetic separation

International Nuclear Information System (INIS)

Bradbury, D.; Elder, G.R.; Tucker, P.M.; Dunn, M.J.

1992-01-01

Removal of trace quantities of heavy metal or radionuclide contamination from solutions at high flow rate presents a considerable technical challenge. Low flow methods of treatment such as particle gravity settling require expensive large volume equipment, whereas traditional methods of filtration demand significant energy costs. Magnetic filtration can be used to provide a low cost method of solid-liquid separation at high flow rate, provided contaminants can be selectively bound to a magnetic solid particle. This paper describes recent progress with this technique including performance tests of composite materials produced to selectively remove specific contaminants such as cesium, uranium, lead, cadmium, and mercury from solution

Chemical speciation of radionuclides migrating in groundwaters

International Nuclear Information System (INIS)

Robertson, D.; Schilk, A.; Abel, K.; Lepel, E.; Thomas, C.; Pratt, S.; Cooper, E.; Hartwig, P.; Killey, R.

1994-04-01

In order to more accurately predict the rates and mechanisms of radionuclide migration from low-level waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particular, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species that appear to be predominantly organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g., 60 Co and 106 Ru, into a number of specific compounds or groups of compounds. Further identification of the anionic organoradionuclide complexes is planned utilizing high resolution mass spectrometry. Large-volume ultra-filtration experiments are characterizing the particulate forms of radionuclides being transported in these groundwaters

One-step separation by thermal treatment and cobalt acid-leaching from spent lithium-ion batteries

Science.gov (United States)

Mu, Deying

2017-10-01

Lithium-ion batteries are extensively used in portable storage devices and automobiles, therefore the environment and resource problems caused by spent lithium ion batteries have become increasingly severe. This paper focuses on the recovery process of spent lithium cobalt oxide active material and comes up with reasonable processes and the best conditions for cobalt leaching ultimately.

Ion exchange of Cobalt and Cadmium in Zeolite X

International Nuclear Information System (INIS)

Nava M, I.

1994-01-01

The growing development in the industry has an important contribution to the environmental damage, where the natural effluents are each day more contaminated by toxic elements, such as: mercury, chromium, lead and cadmium. So as to separate such elements it has sorbent must have enough stability, and have a sharp capacity of sorption. In this work it was studied the sorption behavior of cobalt and on the other hand, cadmium in aqueous solutions, which along with sodic form of the Zeolite X, undergoes a phenomenon of ionic interchange. Such interchange was verify to different concentration of cadmium, cobalt and hydronium ion. The content of cobalt and sodium in the interchanged samples was detected through the neutronic activation analysis. The results disclose a higher selectivity for cadmium than cobalt. (Author)

Bioaccumulation factors for radionuclides in freshwater biota

International Nuclear Information System (INIS)

Vanderploeg, H.A.; Parzyck, D.C.; Wilcox, W.H.; Kercher, J.R.; Kaye, S.V.

1975-11-01

This report analyzes over 200 carefully selected papers to provide concise data sets and methodology for estimation of bioaccumulation factors for tritium and isotopes of strontium, cesium, iodine, manganese, and cobalt in major biotic components of freshwater environments. Bioaccumulation factors of different tissues are distinguished where significant differences occur. Since conditions in the laboratory are often unnatural in terms of chemical and ecological relationships, this review was restricted as far as possible to bioaccumulation factors determined for natural systems. Because bioaccumulation factors were not available for some shorter-lived radionuclides, a methodology for converting bioaccumulation factors of stable isotopes to those of shorter-lived radionuclides was derived and utilized. The bioaccumulation factor for a radionuclide in a given organism or tissue may exhibit wide variations among bodies of water that are related to differences in ambient concentrations of stable-element and carrier-element analogues. To account for these variations, simple models are presented that relate bioaccumulation factors to stable-element and carrier-element concentrations in water. The effects of physicochemical form and other factors in causing deviations from these models are discussed. Bioaccumulation factor data are examined in the context of these models, and bioaccumulation factor relations for the selected radionuclides are presented

A new refillable Cobalt-57 flood phantom to measure camera uniformity

International Nuclear Information System (INIS)

Dias-Neto, A.; Silva, C.P.G. da; Osso, J.

1997-01-01

Full text: The system uniformity of a scintillation camera is assessed using an extended Tc-99m source: a well constructed flood phantom, filled with a solution of Tc-99m pertechnetate, that does not bulge and is well mixed. A convenient substitute is a commercial solid Co-57 sheet source, which is expensive (5k-10k USS), has a relative short life-span (1,5 - 2 years), and, may not be quite uniform. As an alternative, an inexpensive fillable Co-57 flood source is presented. For pilot testing, a plastic flood phantom was filled with a solution of Co-57 chloride produced by IPEN's cyclotron. Special filling plugs with O-rings were used to avoid any leakage. High count uniformity images, using a low-energy high-resolution collimator and 15% energy windows, were obtained with the fillable Co-57 source, a commercial Co-57 sheet source, and a Tc-99 source. The data were compared visually and quantified with the NEMA uniformity parameters. The fillable Co-57 source compared favourably with the other sources. A shock-proof flood phantom is at present under development. This phantom is intended to be refilled annually with Co-57, at a fraction of the cost of a commercial sheet source. (authors)

Recent advances in the development of a cobalt dicarbollide based solvent extraction process for the separation of Cs and Sr from spent fuel

International Nuclear Information System (INIS)

Law, Jack D.; Todd, Terry A.; Peterman, D.R.; Herbst, R.S.; Tillotson, R.D.

2004-01-01

As part of the Advanced Fuel Cycle Initiative (AFCI), a chlorinated cobalt dicarbollide (CCD)/polyethylene glycol (PEG) based solvent extraction process is being developed for the separation of Cs and Sr from leached spent light water reactor (LWR) fuel. The separation of Cs and Sr would significantly reduce the short-term heat generation of spent nuclear fuel requiring geological disposal. Recent advances in the development of a CCD/PEG process will be presented. The data presented will include acid dependency data, results of batch contact testing using simulant feeds traced with 137 Cs, 90 Sr and 241 Am as well as results of testing to evaluate extractant composition. The impacts of other separation process in an advanced aqueous separation flow sheet on the effectiveness of the CCD/PEG process will be detailed. (authors)

Nuclear separations for radiopharmacy : the need for improved separations to meet future research and clinical demands

International Nuclear Information System (INIS)

Bond, A.H.; Rogers, R.D.; Dietz, M.L.

2000-01-01

Several recent national and international reports have predicted that the demand for radionuclides used in medicine will increase significantly over the next 20 years. Separation science is an integral part of the production and development of new radionuclides for diagnostic and therapeutic applications and will play a major role in process improvements to existing radiopharmaceuticals to meet increasing demands. The role of separation science in the production of radionuclides for medical applications is briefly discussed, followed by an overview of the manuscripts from the American Chemical Society symposium 'Nuclear Separations for Radiopharmacy'. A listing of the most widely used radionuclides in clinical application and medical research serves as a foundation for the discussion of future research opportunities in separation science

Leaching kinetics of cobalt from the scraps of spent aerospace magnetic materials.

Science.gov (United States)

Zhou, Xuejiao; Chen, Yongli; Yin, Jianguo; Xia, Wentang; Yuan, Xiaoli; Xiang, Xiaoyan

2018-06-01

Based on physicochemical properties of the scraps of spent aerospace magnetic materials, a roasting - magnetic separation followed by sulfuric acid leaching process was proposed to extract cobalt. Roasting was performed at 500 °C to remove organic impurity. Non-magnetic impurities were reduced by magnetic separation and then the raw material was sieved into desired particle sizes. Acid leaching was carried out to extract cobalt from the scraps and experimental parameters included agitation speed, particle size, initial concentration of sulfuric acid and temperature. Agitation speed higher than 300 r/min had a relatively small impact on the cobalt extraction. As the particle size reduced, the content of cobalt in the raw material decreases and the extraction of cobalt by acid leaching increased at first and decreased afterwards. Raising the initial concentration of sulfuric acid and temperature contributed to improve the cobalt extraction and the influence of temperature was more remarkable. SEM image revealed that the spent aerospace magnetic materials mainly existed in the sliced strip flake with a loose surface and porous structure. Under the experimental condition, the leaching rate of cobalt from the scraps in sulfuric acid solution could be expressed as ln(-ln(1 - α)) = lnk + nlnt. The apparent activation energy was found to be 38.33 kJ/mol and it was mainly controlled by the surface chemical reaction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Potential for cobalt recovery from lateritic ores in Europe

Science.gov (United States)

Herrington, R.

2012-04-01

Cobalt is one of the 'critical metals' identified under the EU Raw Materials Initiative. Annually the global mine production of cobalt is around 55,000 tonnes,with Europe's industries consuming around 30% of that figure. Currently Europe produces around 27 tonnes of cobalt from mines in Finland although new capacity is planned. Co-bearing nickel laterite ores being mined in Greece, Macedonia and Kosovo where the cobalt is currently not being recovered (ores have typical analyses of 0.055% Co and >1% Ni,). These ores are currently treated directly in pyrometallurgical plants to recover the contained nickel and this process means there is no separate cobalt product produced. Hydrometallurgical treatment of mineralogically suitable laterite ores can recover the cobalt; for example Cuba recovers 3,500 tonnes of cobalt from its laterite mining operations, which are of a similar scale to the current European operations. Implementation of hydrometallurgical techniques is in its infancy in Europe with one deposit in Turkey planning to use atmospheric heap leaching to recover nickel and copper from oxide-dominated ores. More widespread implementation of these methods to mineralogically suitable ore types could unlock the highly significant undeveloped resources (with metal contents >0.04% Co and >1% Ni), which have been defined throughout the Balkans eastwards into Turkey. At a conservative estimate, this region has the potential to supply up to 30% of the EU cobalt requirements.

Sorption behavior of cesium, cobalt and europium radionuclides onto hydroxyl magnesium silicate

Energy Technology Data Exchange (ETDEWEB)

Hamed, Mostafa M.; Holiel, M.; Ahmed, I.M. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories and Waste Management Center

2016-07-01

The radioactive wastes from different activities have to be safely disposed of and isolated from the human environment. The retardation of radioactive materials by designed barriers is originally controlled by the sorption ability of the mineral compositions. In this work, a naturally available mineral composite, a hydroxyl magnesium silicate (HMS) was investigated as potential natural inorganic sorbent for the retention of long-lived radionuclides ({sup 134}Cs, {sup 60}Co and {sup 152+154}Eu) from aqueous solutions. The factors affecting the sorption process, such as contact time and pH were evaluated. Furthermore X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal and thermogravimetry analyses (DTA/TGA) measurements were examined in order to assess the physicochemical properties of the magnesium silicate mineral. Langmuir and Freundlich isotherms fitted the result s substantially better than the Flory-Huggins isotherm and the sorption was found to follow pseudo-first order kinetic model. The proposed mineral has been successfully applied for the sorption of {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu radionuclides from real radioactive waste. The results indicated that about 97.4-99% of {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu radionuclides were efficiently retained onto the HMS mineral. Based on the results obtained, it can be concluded that the HMS mineral is an economic and efficient retaining material for environmental hazardous migration and/or leakage of some radionuclides such as {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu and trivalent actinide ({sup 241}Am, {sup 242m}Am and {sup 243}Am) ions. Therefore, this study could be used as a starting point to establish and consider that mineral as an engineered barrier around the disposal facilities at the nuclear activity centres.

Preconcentration and separation of nickel, copper and cobalt using solid phase extraction and their determination in some real samples

International Nuclear Information System (INIS)

Ghaedi, M.; Ahmadi, F.; Soylak, M.

2007-01-01

A solid phase extraction method has been developed to separate and concentrate trace amounts of nickel, cobalt and copper ions from aqueous samples for the measurement by flame atomic absorption spectrometry. By the passage of aqueous samples through activated carbon modified by dithioxamide (rubeanic acid) (DTO), Ni 2+ , Cu 2+ and Co 2+ ions adsorb quantitatively. The recoveries of analytes at pH 5.5 with 500 mg solid phase were greater than 95% without interference from alkaline, earth alkaline and some metal ions. The enrichment factor was 330. The detection limits by three sigma were 0.50 μg L -1 for copper, 0.75 μg L -1 for nickel and 0.80 μg L -1 for cobalt. The loading capacity was 0.56 mg g -1 for Ni 2+ , 0.50 mg g -1 for Cu 2+ and 0.47 mg g -1 for Co 2+ . The presented procedure was applied to the determination of analytes in tap, river and sea waters, vegetable, soil and blood samples with successfully results (recoveries greater than 95%, R.S.D. lower than 2% for n = 3)

Preconcentration and separation of nickel, copper and cobalt using solid phase extraction and their determination in some real samples

Energy Technology Data Exchange (ETDEWEB)

Ghaedi, M. [Chemistry Department, University of Yasouj, Yasouj 75914-353 (Iran, Islamic Republic of)]. E-mail: m_ghaedi@mail.yu.ac.ir; Ahmadi, F. [Gachsaran Azad University, Gachsaran (Iran, Islamic Republic of); Soylak, M. [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

2007-08-17

A solid phase extraction method has been developed to separate and concentrate trace amounts of nickel, cobalt and copper ions from aqueous samples for the measurement by flame atomic absorption spectrometry. By the passage of aqueous samples through activated carbon modified by dithioxamide (rubeanic acid) (DTO), Ni{sup 2+}, Cu{sup 2+} and Co{sup 2+} ions adsorb quantitatively. The recoveries of analytes at pH 5.5 with 500 mg solid phase were greater than 95% without interference from alkaline, earth alkaline and some metal ions. The enrichment factor was 330. The detection limits by three sigma were 0.50 {mu}g L{sup -1} for copper, 0.75 {mu}g L{sup -1} for nickel and 0.80 {mu}g L{sup -1} for cobalt. The loading capacity was 0.56 mg g{sup -1} for Ni{sup 2+}, 0.50 mg g{sup -1} for Cu{sup 2+} and 0.47 mg g{sup -1} for Co{sup 2+}. The presented procedure was applied to the determination of analytes in tap, river and sea waters, vegetable, soil and blood samples with successfully results (recoveries greater than 95%, R.S.D. lower than 2% for n = 3)

Preconcentration and separation of nickel, copper and cobalt using solid phase extraction and their determination in some real samples.

Science.gov (United States)

Ghaedi, M; Ahmadi, F; Soylak, M

2007-08-17

A solid phase extraction method has been developed to separate and concentrate trace amounts of nickel, cobalt and copper ions from aqueous samples for the measurement by flame atomic absorption spectrometry. By the passage of aqueous samples through activated carbon modified by dithioxamide (rubeanic acid) (DTO), Ni2+, Cu2+ and Co2+ ions adsorb quantitatively. The recoveries of analytes at pH 5.5 with 500 mg solid phase were greater than 95% without interference from alkaline, earth alkaline and some metal ions. The enrichment factor was 330. The detection limits by three sigma were 0.50 microg L(-1) for copper, 0.75 microg L(-1) for nickel and 0.80 microg L(-1) for cobalt. The loading capacity was 0.56 mg g(-1) for Ni2+, 0.50 mg g(-1) for Cu2+ and 0.47 mg g(-1) for Co2+. The presented procedure was applied to the determination of analytes in tap, river and sea waters, vegetable, soil and blood samples with successfully results (recoveries greater than 95%, R.S.D. lower than 2% for n=3).

Application of partition chromatography method for separation and analysis of actinium radionuclides

International Nuclear Information System (INIS)

Sinitsina, G.S.; Shestakova, I.A.; Shestakov, B.I.; Plyushcheva, N.A.; Malyshev, N.A.; Belyatskij, A.F.; Tsirlin, V.A.

1979-01-01

The method of partition chromatography is considered with the use of different extractants for the extraction of actinium-227, actinium-225 and actinium-228. It is advisable to extract actinium-227 from the irradiated radium with the help of D2FGFK. The use of 2DEGFK allows us to separate actinium-227 from alkaline and alkaline-earth elements. Amines have a higher radiative stability. An express-method has been developed for the identification of actinium-227 with TOA by its intrinsic α-emission in nonequilibrium preparations of irradiated radium-226 of small activity. Actinium-225 is extracted from uranium-233 with due regard for the fact that U, Th, and Ac are extracted differently by TBP from HNO 3 solutions. With the help of the given procedure one can reach the purifying coefficient of 10 4 . Actinium-228 is extracted from the radiummesothorium preparations by a deposition of decay products, including polonium-210 on the iron hydroxyde. Actinium-228 extraction from the mixture of radium radionuclides is performed by the partition chromatography method on D2EGFK. All the procedures for separation of actinium isotopes by the above methods are described

Comparison of extraction chromatography and a procedure based on the molecular recognition method as separation methods in the determination of neptunium and plutonium radionuclides

International Nuclear Information System (INIS)

Strisovska, Jana; Galanda, Dusan; Drabova, Veronika; Kuruc, Jozef

2012-01-01

The potential of various types of sorbents for separation of radionuclides of plutonium and neptunium were examined. Extraction chromatography and a procedure based on the molecular recognition method were used for the separation. The suitability of the various sorbent types and brands for this purpose was determined. (orig.)

Synthesis of potassium cobalt hexacyanoferrate encapsulated polymeric beads for extraction of Cs from acidic solution

International Nuclear Information System (INIS)

Kanagare, Anant B.; Singh, Krishan Kant; Kumar, Manmohan; Shinde, Vaishali S.

2016-01-01

137 Cs is one of the major radionuclides formed during the fission of 235 U in nuclear reactors. It is a main source of radiation in High Level Liquid Waste (HLLW) generated after the reprocessing of spent nuclear fuel. Separation of Cs from HLLW, decreases radiation exposure throughout the vitrification process and avoids thermal deformation of conditioned waste matrix during storage. Therefore, there is a necessity for selective separation of Cs from HLLW and other such acidic waste streams. The liquid-liquid extraction is widely used as a technology for separation and recovery of metal ions from radioactive wastes. Such technologies play an important role in all the bulk separation processes, but they have noticeable limitations, such as difficulty in handling, losses of extractant in aqueous phase, secondary waste generation, third phase problems at higher metal loading, etc. Due to these limitations it is necessary to explore the advance, more capable and exactly feasible alternatives. In this respect it is assumed that solid-liquid based Extractant Encapsulated Polymeric Beads (EEPBs) may resolve some of these limitations. The metal hexacyanoferrates (HCFs) are preferred as Cs extractant over the other materials due to their selectivity and high capacity to remove cesium from aqueous radioactive wastes. Here we report the synthesis and characterization of a novel potasium cobalt hexacyanoferrate (KCoHCF) encapsulated polyether sulphone beads, and its use as a cesium sorbent material

Environmentally-friendly oxygen-free roasting/wet magnetic separation technology for in situ recycling cobalt, lithium carbonate and graphite from spent LiCoO{sub 2}/graphite lithium batteries

Energy Technology Data Exchange (ETDEWEB)

Li, Jia; Wang, Guangxu; Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn

2016-01-25

Highlights: • The idea of “waste + waste → resources.” was used on this study. • Based on thermodynamic analysis, the possible reaction between LiCoO{sub 2} and graphite was obtained. • The residues of oxygen-free roasting are cobalt, lithium carbonate and graphite. • The recovery rate of Co and Li is 95.72% and 98.93% after wet magnetic separation. • It provides the rationale for environmental-friendly recycling spent LIBs in industrial-scale. - Abstract: The definite aim of the present paper is to present some novel methods that use oxygen-free roasting and wet magnetic separation to in situ recycle of cobalt, Lithium Carbonate and Graphite from mixed electrode materials. The in situ recycling means to change waste into resources by its own components, which is an idea of “waste + waste → resources.” After mechanical scraping the mixed electrode materials enrich powders of LiCoO{sub 2} and graphite. The possible reaction between LiCoO{sub 2} and graphite was obtained by thermodynamic analysis. The feasibility of the reaction at high temperature was studied with the simultaneous thermogravimetry analysis under standard atmospheric pressure. Then the oxygen-free roasting/wet magnetic separation method was used to transfer the low added value mixed electrode materials to high added value products. The results indicated that, through the serious technologies of oxygen-free roasting and wet magnetic separation, mixture materials consist with LiCoO{sub 2} and graphite powders are transferred to the individual products of cobalt, Lithium Carbonate and Graphite. Because there is not any chemical solution added in the process, the cost of treating secondary pollution can be saved. This study provides a theoretical basis for industrial-scale recycling resources from spent LIBs.

Leaching of artificial radionuclide out of minerals

International Nuclear Information System (INIS)

Bogdanov, R.V.; Osipova, I.V.; Sergeev, A.S.

1992-01-01

Leaching of radionuclides induced by neutron bombardment in natural silicates and silicophosphate of rare earth elements and calcium, is studied using gamma-spectrometry. It is shown that solution of minerals under the effect of artificial subsoil water at 75 deg C is incongruent character: difference in leaching of cobalt and actinides reaches value equal to two magnitudes. Behaviour of lanthanides as analogs of transplutonium elements is of special interest. Essential role of specimen microphase composition is pointed out. The suggested methodological approach is efficient at selection of matricies for fixaton of radioactive wastes

Development and application of an on-line sequential injection system for the separation of artificial and natural radionuclides in environmental samples

International Nuclear Information System (INIS)

Kim, C.-K.; Sansone, U.; Martin, P.; Kim, C.-S.

2007-02-01

The Chemistry Unit of the Physics, Chemistry and Instrumentation Laboratory in the IAEA's Seibersdorf Laboratory in Austria, has the programmatic responsibility to provide assistance to Member State laboratories in maintaining and improving the reliability of analytical measurement results, both in trace element and radionuclide determinations. This is accomplished through the provision of reference materials of terrestrial origin, validated analytical procedures, training in the implementation of internal quality control, and through the evaluation of measurement performance by organization of worldwide and regional interlaboratory comparison exercises. In this framework an on-line sequential injection (SI) system was developed, which can be widely used for the separation and preconcentration of target analytes from diverse environmental samples. The system enables the separation time to be shortened by maintaining a constant flow rate of solution and by avoiding clogging or bubbling in a chromatographic column. The SI system was successfully applied to the separation of Pu in IAEA reference material (IAEA Soil-6) and to the sequential separation of 210 Po and 210 Pb in phosphogypsum candidate reference material. The replicate analysis results of Pu in IAEA reference material (Soil-6) obtained with the SI system are in good agreement with the recommended value within 5% of standard deviation. The SI system enabled a halving in the separation time required for of radionuclides

Effect of n-octanol on the extraction behavior of trace cobalt in TOA-HCl system

International Nuclear Information System (INIS)

Mukhopadhyay, Krishnendu; Mandal, Anjana; Mukhopadhyay, Banani; Nayak, Dalia; Lahiri, Susanta

1997-01-01

Effect of the presence of n-octanol in the extraction of traces of cobalt in HCl-TOA system was studied. In the extraction, both synergistic and antagonistic effects, depending on the volume of alcohol present, were observed. Extraction behaviour of the element was studied radiometrically using 57,58 Co, produced by α- particle bombardment of cobalt, as radiotracer for the element. (author). 1 fig

Development of a Cloud-Point Extraction Method for Cobalt Determination in Natural Water Samples

Directory of Open Access Journals (Sweden)

Mohammad Reza Jamali

2013-01-01

Full Text Available A new, simple, and versatile cloud-point extraction (CPE methodology has been developed for the separation and preconcentration of cobalt. The cobalt ions in the initial aqueous solution were complexed with 4-Benzylpiperidinedithiocarbamate, and Triton X-114 was added as surfactant. Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the cobalt content was measured by flame atomic absorption spectrometry. The main factors affecting CPE procedure, such as pH, concentration of ligand, amount of Triton X-114, equilibrium temperature, and incubation time were investigated and optimized. Under the optimal conditions, the limit of detection (LOD for cobalt was 0.5 μg L-1, with sensitivity enhancement factor (EF of 67. Calibration curve was linear in the range of 2–150 μg L-1, and relative standard deviation was 3.2% (c=100 μg L-1; n=10. The proposed method was applied to the determination of trace cobalt in real water samples with satisfactory analytical results.

Temperaturedependent After-Effects of the Cobalt-57-Iron-57 Electron-Capture Reaction in Cd3[57Co(CN)6]2,12H2O

DEFF Research Database (Denmark)

Fenger, Jes; Olsen, Jørgen

1974-01-01

The Mössbauer emission spectrum of Cd3[57Co(CN)6]2,12H2O was measured at temperatures between 78 and 323 K. Above 200 K the spectra can be resolved into two doublets; one is ascribed to 57Fe(CN)63– and one to 57Fe(CN)52–; it is suggested that the pentacyanide is formed by a Coulomb explosion...... following an Auger process associated with the 57Co(EC)57Fe-decay. Below 200 K a third species is detected; it may be Fe2+ formed by cyanide linkage isomerism. Measurements of the total intensity of the spectrum and the relative intensities of the individual doublets as a function of temperature permit...... in principle a determination of the f-factors for the species formed. It is estimated that the 57Fe(CN)52– has a formal Debye temperature of 170 K; at room temperature it is detected with a probability of only 50% of that of the 57Fe(CN)63–....

Pyrometallurgical separation processes of radionuclides contained in the irradiated nuclear fuel

International Nuclear Information System (INIS)

De Cordoba, Guadalupe; Caravaca, Concha; Quinones, Javier; Gonzalez de la Huebra, Angel

2005-01-01

Faced with the new options for the high level waste management, the ''Partitioning and Transmutation (P and T)'' of the radio nuclides contained in the irradiated nuclear fuel appear as a promising option from different points of view, such as environmental risk, radiotoxic inventory reduction, economic, etc.. The present work is part of a research project called ''PYROREP'' of the 5th FWP of the EU that studied the feasibility of the actinide separation from the rest of fission products contained in the irradiated nuclear fuel by pyrometallurgical processes with the aim of their transmutation. In order to design these processes it is necessary to determine basic thermodynamic and kinetic data of the radionuclides contained in the nuclear fuel in molten salt media. The electrochemical study of uranium, samarium and molybdenum in the eutectic melt LiCl - KCl has been performed at a tungsten electrode in the temperature range of 450 - 600 deg C in order to obtain these basic properties. (Author)

Preparation of radioactive labelled (57Co) sulfitocobalamin

International Nuclear Information System (INIS)

Begley, J.A.; Horch, C.; Hall, C.A.

1978-01-01

Farquharson and Adams have identified sulfitocobalamin (SO3-Cb1) as one of the naturally occurring cobalamins (Cb1s) in foods. We have devised a method of making radioactive labelled SO3-Cb1 for in vivo and in vitro studies of this form of Cb1. Cobalt-57 labelled cyanocobalamin (57Co CN-Cb1) was acid photolyzed to 57Co hydroxocobalamin (57Co OH-Cb1) followed by ligand substitution with SO3-2 ion from aqueous sodium (meta) bisulfite in the dark. The resulting 57Co SO3-Cb1 was purified by organic extraction and cation exchange chromatography. The final preparation was greater than 99% 57Co SO3-Cb1 with an overall yield of greater than 70%, stable for up to four weeks at 20 degrees C in the dark, and capable of binding to the human Cb1 binding proteins Transcobalamin II (TC II), Intrinsic factor (IF), and Salivary R. This method allows a simple 1 day preparation of high specific activity labelled 57Co SO3-Cb 1 for biological studies

Heavy metals and their radionuclides uptake by Bacillus Licheniformis

International Nuclear Information System (INIS)

Ramadan, A.A.; Ahmed, M.M.; Abo-state, M.A.M.; Sarhan, M.; Faroqe, M.

2007-01-01

Bacillus licheniformis is a gram positive spore forming bacterium. Different concentrations of cobalt affected the ability of Co uptake and growth of Bacillus licheniformis. As the concentration increased, both the uptake and growth were decreased. Maximum Co uptake was found at ph 7.0, while for growth was ph 8.0. The optimum temperature for uptake and growth was 40 degree C and 20% inoculum size represents the maximum cobalt uptake by Bacillus licheniformis. Also, maximum uptake was recorded after 72 hours, incubation period. As the concentration of cesium was increased till 400 mg/l, the uptake was also increased. The optimum cesium uptake and growth was at ph 8.0. The optimum growth was at 45 degree C while Cs uptake was found at 35 degree C and 15% inoculum size represented the maximum Cs uptake. After 72 hour incubation period, maximum Cs uptake was recorded. Generally, Bacillus licheniformis removed more than 80% of Co and 50% of Cs from the broth medium. Addition of clay to Bacillus licheniformis increased both Co or Cs uptake. Bacillus licheniformis was gamma resistant and 10 KGy reduced the viability by 5.3 log cycles. The irradiated and non-irradiated cultures can grow on 500 or 700 mg Co or Cs. Bacillus licheniformis removed 99.32% of the Co radionuclides and 99.28% of Cs radionuclides

The effect of organics on the sorption of cobalt by glacial sand in laboratory batch experiments

International Nuclear Information System (INIS)

Haigh, D.G.; Williams, G.M.; Hooker, P.J.; Ross, C.A.M.; Allen, M.R.; Warwick, P.

1989-01-01

Acetate, EDTA and organic compounds naturally present in groundwater at the Drigg in situ radionuclide migration experimental site, have been studied to assess their effect on the sorption of cobalt by glacial sand in a series of batch experiments. Removing 56% of the natural organic material from the grounwater with DEAE cellulose increased the distribution ratio (R d ) of cobalt by a factor of about two. EDTA had a dramatic effect on the sorption of Co even at low concentrations, reducing the R d by up to two orders of magnitude. At EDTA concentrations greater than 5 mg/l, there was no further reduction in sorption. EDTA was not itself sorbed, but formed a mobile complex with Co. Differences in distribution ratios were observed depending on whether the cobalt was added before or after EDTA. Within the same period of equilibrium, the R d values were higher when cobalt was allowed to equilibrate with the sand before adding EDTA. The desorption of cobalt from the mineral surface may be a rate-limiting step such that equilibrium was not achieved within the 14-day period of these experiments. Acetate had no effect on cobalt sorption in any of the experiments undertaken. This work is part of the Commission Mirage project, Phase 2, research area Geochemistry of actinides and fission products in natural aquifer systems

Development of polymer-extractant composite beads for separation of radionuclides

International Nuclear Information System (INIS)

Kumar, Manmohan; Singh, Krishankant; Bajaj, P.N.

2009-01-01

A novel micro porous polymer-extractant composite bead system, containing liquid extractant encapsulated in the core of a polymeric shell, with required porosity and hydrophilicity, to allow exchange of radionuclides without, any significant leaching out of the encapsulated extractant, has been developed for solid-liquid extraction of radionuclides from acidic waste solutions. The reuse of the beads is possible as there is practically no change in its radionuclide extraction efficiency, after repeated extraction second time. The high porosity and hydrophilicity of the synthesized TBP-encapsulated polymeric beads is evident from the presence of ∼ 78% water in the swollen condition. Evaluation of the synthesized beads for extraction of uranium and plutonium from aqueous acidic waste solutions, indicated possibility of their use under the conditions of PUREX process. The aliquate 336-encapsulated polymeric beads showed selective extraction of plutonium from aqueous nitrate solutions in the presence of uranium, and back extraction of the loaded plutonium, using dilute nitric acid or ascorbic acid. (author)

Separation of radionuclides from gas by sorption on activated charcoal and inorganic sorbents

International Nuclear Information System (INIS)

Kepak, F.

1988-01-01

The review deals with the sorption and ion exchange of gaseous radionuclides on activated charcoal and on inorganic sorbents. It presents the physical and chemical characteristics of radionuclides, the sources of gaseous forms of radionuclides as well as the composition of radioactive gases from some nuclear facilities. 79 refs. (author)

Transport of radionuclides from the LAMPF lagoons

International Nuclear Information System (INIS)

Ferenbaugh, R.W.; Purtymun, W.D.

1985-01-01

Monitoring of the discharge water from the Los Alamos Meson Physics Facility lagoons continued during June and December of 1983. The list of radionuclides being monitoring includes 7 Be, 57 Co, 134 Cs, 3 H, 54 Mn, 22 Na, and 83 Rb. The sampling locations and the data obtained to date are presented. Movement of radionuclides around the lagoons has been described in a previous report. 1 reference, 1 table

XAS Investigation of bio-relevant cobalt complexes in aqueous media

International Nuclear Information System (INIS)

Bresson, C.; Lamouroux, C.; Esnouf, S.; Solari, P.L.; Den Auwer, C.

2006-01-01

Cobalt is an essential element of biological cycles involved in numerous metallo-biomolecules, but it becomes a toxic element at high concentration or a radio-toxic element because of its use in the nuclear industry. 'Molecular speciation' in biological media is an essential prerequisite to evaluate its chemical behaviour as well as its toxic or beneficial effects. In this scheme, we have focused on the coordination properties of the thiol-containing amino acid cysteine (Cys) and the pseudo-peptide N-(2-mercapto-propionyl) glycine (MPG) towards the Co 2+ cation in aqueous media. XAS at the Co K edge and traditional spectroscopic techniques have been coupled in order to structurally characterize the cobalt coordination sphere. Oxidation states and geometries of the bis- and tris-cysteinato Co(III) complexes are in agreement with the literature data. In addition, bond lengths between the metallic centre and the donor atoms have been determined. The structure of a new dimeric N-(2-mercapto-propionyl) glycinato Co(II) complex in solution is also reported. The coordination of MPG to Co(II) through the thiolate and carboxylate functions is ascertained. This work provides fundamental structural information about bio-relevant complexes of cobalt, which will contribute to our understanding of the chemical behaviour and the biological role of this radionuclide. (authors)

Detection limit improvements forecasted at CTBTO IMS radionuclide stations based on size separation of aerosols by aerodynamic diameter

International Nuclear Information System (INIS)

Biegalski, S.; Ezekoye, O.A.; Pena, J.M.; Waye, S.; Pickering, M.

2008-01-01

Studies show that aerosols with natural activity have an aerodynamic diameter in the range of 0.1 to 1 μm. In contrast, nuclear explosions generally produce radioactive aerosols with aerodynamic diameters less than 0.1 μm and greater than 1 μm. These differences in aerosol sizes are quite fortuitous because they allow aerosol aerodynamic diameter to be utilized as a physical property to separate aerosols of natural origin from those produced in a nuclear explosion. Data collected in Austin, TX and at U.S. CTBT IMS radionuclide stations have been utilized to forecast detection limit improvements possible given an aerosol size separation capability. (author)

The use of radiocobalt as a label improves imaging of EGFR using DOTA-conjugated Affibody molecule.

Science.gov (United States)

Garousi, Javad; Andersson, Ken G; Dam, Johan H; Olsen, Birgitte B; Mitran, Bogdan; Orlova, Anna; Buijs, Jos; Ståhl, Stefan; Löfblom, John; Thisgaard, Helge; Tolmachev, Vladimir

2017-07-20

Several anti-cancer therapies target the epidermal growth factor receptor (EGFR). Radionuclide imaging of EGFR expression in tumours may aid in selection of optimal cancer therapy. The 111 In-labelled DOTA-conjugated Z EGFR:2377 Affibody molecule was successfully used for imaging of EGFR-expressing xenografts in mice. An optimal combination of radionuclide, chelator and targeting protein may further improve the contrast of radionuclide imaging. The aim of this study was to evaluate the targeting properties of radiocobalt-labelled DOTA-Z EGFR:2377 . DOTA-Z EGFR:2377 was labelled with 57 Co (T 1/2  = 271.8 d), 55 Co (T 1/2  = 17.5 h), and, for comparison, with the positron-emitting radionuclide 68 Ga (T 1/2  = 67.6 min) with preserved specificity of binding to EGFR-expressing A431 cells. The long-lived cobalt radioisotope 57 Co was used in animal studies. Both 57 Co-DOTA-Z EGFR:2377 and 68 Ga-DOTA-Z EGFR:2377 demonstrated EGFR-specific accumulation in A431 xenografts and EGFR-expressing tissues in mice. Tumour-to-organ ratios for the radiocobalt-labelled DOTA-Z EGFR:2377 were significantly higher than for the gallium-labelled counterpart already at 3 h after injection. Importantly, 57 Co-DOTA-Z EGFR:2377 demonstrated a tumour-to-liver ratio of 3, which is 7-fold higher than the tumour-to-liver ratio for 68 Ga-DOTA-Z EGFR:2377 . The results of this study suggest that the positron-emitting cobalt isotope 55 Co would be an optimal label for DOTA-Z EGFR:2377 and further development should concentrate on this radionuclide as a label.

Abscess detection with radionuclides

International Nuclear Information System (INIS)

Alavi, J.B.

1988-01-01

Radionuclide studies may aid in the diagnosis and localization of intra-abdominal infections. Despite the introduction of new radiographic and ultrasound methods, there are several clinical situations in which radionuclide scans have proved useful. Those include detection of postoperative intra-abdominal abscess, evaluation of liver abscess, differentiation between pancreatic pseudocyst or abscess, evaluation of fever of unknown origin, and evaluation of inflammatory bowel disease. Each clinical situation is discussed separately here

Behavior of radionuclides in sanitary landfills.

Science.gov (United States)

Chang, K C; Chian, E S; Pohland, F G; Cross, W H; Roland, L; Kahn, B

1984-01-01

his study was undertaken to evaluate the possibility of disposing low-level radioactive waste in sanitary landfills with leachate containment to prevent environmental releases. To meet this objective, two simulated landfills, each 200 l. in volume and containing 55 kg of municipal refuse, were operated in the laboratory with simulated rainfall additions for a 9-month period to observe the extent to which radio-cobalt, -cesium, -strontium and tritium were leached into the liquid phase. One of the units was operated with leachate recycle, the other as a single pass control. Liquid samples were analyzed weekly for 3H, 58Co, 85Sr and 134Cs tracers. Weekly analyses were also performed for approximately 30 parameters to define the degree of stabilization of the waste. Major parameters included BOD, COD, pH and concentrations of specific organics, metals and gases. Concentrations of stable cobalt, strontium and cesium were also measured periodically. Soluble radioactivity levels in both systems were reduced by factors of 50 for 58Co, 5 for 85Sr and 7 for 134Cs, taking radioactive decay and dilution into account. Some radionuclide removal from the liquid phase was associated with major chemical changes in the landfills that occurred within 80 days for the control system and within 130 days for the recycle unit. Observed acid, sulfide, and CO2 concentrations suggested mechanisms for removing some of the radionuclides from leachate. Detection of 3H in the off-gas indicated that less than 1% of tritiated waste became airborne. The waste in the leachate recycle unit was more completely stabilized than in the control unit.

Standardization of sequential separation of naturally occurring radionuclides in drinking water

International Nuclear Information System (INIS)

Nair, Madhu G.; Rao, D.D.; Sathyapriya, R.S.; Sarkar, P.K.

2012-01-01

Human are constantly exposed to radiation originating from natural or manmade sources. The main contribution for internal dose is due to radionuclides from uranium and thorium series in drinking water. The distribution of these elements varies depending on the geological and physiological characteristics of the aquifer. With increased concern for radiological safety of public, it is necessary to evaluate the naturally occurring radionuclides in the drinking water

The use of 57Co-labeled bleomycin in the diagnosis of round lung images

International Nuclear Information System (INIS)

Vaillant, G.; Bertrand, A.; Nouel, J.P.

1975-01-01

As a result of its antimitotic nature, it has been affirmed that labeled bleomycin represents considerable progress in the diagnostic approach to the pulmonary intraparenchymatous round image. A comparative study of uptake of bleomycin, labeled with 57 Co, 67 Ga and 197 Hg, at the level of pulmonary intraparenchymatous round neoplastic foci, was performed on 15 ill subjects. The highest uptakes were obtained with labeled bleomycin. The long half-life of cobalt, however, necessitates extensive precautions to avoid contamination. This justifies the ongoing search for another tracer which can substitute for cobalt and has a shorter period. In addition, examination with cobalt should be reserved for very special cases [fr

Cobalt products from real waste fractions of end of life lithium ion batteries.

Science.gov (United States)

Pagnanelli, Francesca; Moscardini, Emanuela; Altimari, Pietro; Abo Atia, Thomas; Toro, Luigi

2016-05-01

An innovative process was optimized to recover Co from portable Lithium Ion Batteries (LIB). Pilot scale physical pretreatment was performed to recover electrodic powder from LIB. Co was extracted from electrodic powder by a hydrometallurgical process including the following main stages: leaching (by acid reducing conditions), primary purification (by precipitation of metal impurities), solvent extraction with D2EPHA (for removal of metal impurities), solvent extraction with Cyanex 272 (for separation of cobalt from nickel), cobalt recovery (by precipitation of cobalt carbonate). Tests were separately performed to identify the optimal operating conditions for precipitation (pH 3.8 or 4.8), solvent extraction with D2EHPA (pH 3.8; Mn/D2EHPA=4; 10% TBP; two sequential extractive steps) and solvent extraction with Cyanex 272 (pH 3.8; Cyanex/Cobalt=4, 10% TBP, one extractive step). The sequence of optimized process stages was finally performed to obtain cobalt carbonate. Products with different degree of purity were obtained depending on the performed purification steps (precipitation with or without solvent extraction). 95% purity was achieved by implementation of the process including the solvent extraction stages with D2EHPA and Cyanex 272 and final washing for sodium removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polytypic transformations during the thermal decomposition of cobalt hydroxide and cobalt hydroxynitrate

International Nuclear Information System (INIS)

Ramesh, Thimmasandra Narayan

2010-01-01

The isothermal decomposition of cobalt hydroxide and cobalt hydroxynitrate at different intervals of temperature leads to the formation of Co 3 O 4 . The phase evolution during the decomposition process was monitored using powder X-ray diffraction. The transformation of cobalt hydroxide to cobalt oxide occurs via three phase mixture while cobalt hydroxynitrate to cobalt oxide occurs through a two phase mixture. The nature of the sample and its preparation method controls the decomposition mechanism. The comparison of topotactical relationship between the precursors to the decomposed product has been reported in relation to polytypism. - Graphical abstract: Isothermal thermal decomposition studies of cobalt hydroxide and cobalt hydroxynitrate at different intervals of temperature show the metastable phase formed prior to Co 3 O 4 phase.

Research advances in adsorption treatment of cesium and cobalt in waste liquid of nuclear power plants by ion exchange resin

International Nuclear Information System (INIS)

Liu Dan; Wang Xin; Liu Jiean; Zhu Laiye; Chen Bin; Weng Minghui

2014-01-01

Liquid radwaste is unavoidably produced during the operation of nuclear power plants (NPP). With the development of China's nuclear power, much more attention will be paid to the impact of NPP construction on water environment. Radionuclides are the main targets for adsorption treatment of NPP liquid radwaste. Thereinto, cesium and cobalt are typical cationic ones. Currently, ion exchange process is widely used in liquid radwaste treatment system (WLS) of NPP, wherein resin plays a key role. The paper reviewed the research progress on adsorption of cesium and cobalt existed in NPP liquid radwaste using ion exchange resin. (authors)

sup(60)Co hot atom chemistry of tris(acetylacetonato) cobalt(III) adsorbed on silica gel

International Nuclear Information System (INIS)

Nishioji, H.; Sakai, Y.; Tominaga, T.

1985-01-01

The sup(60)Co hot atom reactions were studied in tris(acetylacetonato)cobalt(III) adsorbed on silica gel surface. sup(57)Fe Moessbauer spectra of tris(acetylacetonato)iron(III) in the corresponding system were also measured in order to examine the state of dispersion of complex molecules on silica gel. The retention formation processes were discussed in terms of the dependence of sup(60)Co retention on the adsorbed amount (concentration) of cobalt(III) complexes. (author)

The use of radiocobalt as a label improves imaging of EGFR using DOTA-conjugated Affibody molecule

DEFF Research Database (Denmark)

Garousi, Javad; Andersson, Ken G; Dam, Johan H

2017-01-01

-expressing xenografts in mice. An optimal combination of radionuclide, chelator and targeting protein may further improve the contrast of radionuclide imaging. The aim of this study was to evaluate the targeting properties of radiocobalt-labelled DOTA-ZEGFR:2377. DOTA-ZEGFR:2377 was labelled with (57)Co (T1/2 = 271.8 d......), (55)Co (T1/2 = 17.5 h), and, for comparison, with the positron-emitting radionuclide (68)Ga (T1/2 = 67.6 min) with preserved specificity of binding to EGFR-expressing A431 cells. The long-lived cobalt radioisotope (57)Co was used in animal studies. Both (57)Co-DOTA-ZEGFR:2377 and (68)Ga-DOTA......Several anti-cancer therapies target the epidermal growth factor receptor (EGFR). Radionuclide imaging of EGFR expression in tumours may aid in selection of optimal cancer therapy. The (111)In-labelled DOTA-conjugated ZEGFR:2377 Affibody molecule was successfully used for imaging of EGFR...

Blood doping by cobalt. Should we measure cobalt in athletes?

Directory of Open Access Journals (Sweden)

Guidi Gian

2006-07-01

Full Text Available Abstract Background Blood doping is commonplace in competitive athletes who seek to enhance their aerobic performances through illicit techniques. Presentation of the hypothesis Cobalt, a naturally-occurring element with properties similar to those of iron and nickel, induces a marked and stable polycythemic response through a more efficient transcription of the erythropoietin gene. Testing the hypothesis Although little information is available so far on cobalt metabolism, reference value ranges or supplementation in athletes, there is emerging evidence that cobalt is used as a supplement and increased serum concentrations are occasionally observed in athletes. Therefore, given the athlete's connatural inclination to experiment with innovative, unfair and potentially unhealthy doping techniques, cobalt administration might soon become the most suited complement or surrogate for erythropoiesis-stimulating substances. Nevertheless, cobalt administration is not free from unsafe consequences, which involve toxic effects on heart, liver, kidney, thyroid and cancer promotion. Implications of the hypothesis Cobalt is easily purchasable, inexpensive and not currently comprehended within the World Anti-Doping Agency prohibited list. Moreover, available techniques for measuring whole blood, serum, plasma or urinary cobalt involve analytic approaches which are currently not practical for antidoping laboratories. Thus more research on cobalt metabolism in athletes is compelling, along with implementation of effective strategies to unmask this potentially deleterious doping practice

The behaviour of cesium 137, chromium 51, cobalt 60, Manganese 54, sodium 22 and zinc 65 in simulated estuarine environments. Effects of suspended mineral particles and dissolved organic matters

International Nuclear Information System (INIS)

Mahler, P.

1985-09-01

This laboratory investigation studied the retention of 6 radionuclides (cesium 137, chrome 51, cobalt 60, manganese 54, sodium 22 and zinc 65) on three types of clay particles (kaolinite, illite, montmorillonite) and on sediments, suspended in media with salinities ranging between 0 and 34 per mill, with or without organic matters. Measurement of the radioactivity retained by the particles after 5 days' contact with the radionuclide made it possible to calculate the percentages retained and the distribution coefficients, and to follow their evolution versus salinity. Parallel experiments studied the behaviours of the 6 radionuclides as a function of experimental factors (wall effect, contact time..). An exhaustive bibliographic review gives the state-of-the-art of the knowledge. The following conclusions were derived: - the retention of all the radionuclides but chromium 51 decreased as soon as a low salinity appeared. Chromium (available as Cr 3+ ) precipitated quickly and strongly during fixation whatever the surfaces or the conditions: - as for the role of the clay type, illite showed a strong affinity for cesium 137; manganese 54 had a particular behaviour with montmorillonite that enhanced its precipitation into MnO 2 ; with cobalt, sodium and zinc, the percentages retained were always [fr

Studies on separation, conversion and transmutation of long-living radionuclides. A contribution to advanced disposal of high-level radioactive wastes

International Nuclear Information System (INIS)

Modolo, Giuseppe

2014-01-01

The future role and acceptance of nuclear energy will be decisively determined by the safe operation of existing and future facilities and by convincing solutions for nuclear waste management. With respect to the long half-lives of some radionuclides (actinides and fission products) and the related question as to whether the release of radionuclides from a repository can be prevented over very long periods of time, alternatives to the direct disposal of spent nuclear fuels are discussed internationally. As a potential complementary solution, the technological option with partitioning and transmutation (P and T) is considered. This method separates and converts the long-lived radionuclides into stable, short-lived nuclides via neutron reactions in dedicated facilities. Against this background, the first main chapter of the present work looks at the chemical separation of actinides from high-level reprocessing wastes. In order to achieve a better understanding of the processes at the molecular level, basic investigations were also performed on separating actinides(III) via liquid-liquid or liquid-solid extraction. At the same time, reversible processes were developed and tested on the laboratory scale with the aid of mixer-settlers and centrifugal extractors. The subsequent chapter focuses on separating the long-lived fission product iodine-129 from radioactive wastes as well as from process effluents arising from reprocessing. As part of this work, different simple chemical and physical techniques were developed for complete recovery with respect to transmutation or conditioning in host matrices that are sufficiently stable for final storage. Its high mobility and radiological properties make iodine-129 relevant for the long-term safety assessment of final repositories. In addition, transmutation experiments on iodine-127/129 targets were performed using high-energy protons (145-2600 MeV). Due to the expected low cross sections (<100 mb), transmutation with protons

The role of cobalt ferrite magnetic nanoparticles in medical science

International Nuclear Information System (INIS)

Amiri, S.; Shokrollahi, H.

2013-01-01

The nanotechnology industry is rapidly growing and promises that the substantial changes that will have significant economic and scientific impacts be applicable to a wide range of areas, such as aerospace engineering, nano-electronics, environmental remediation and medical healthcare. In this area, cobalt ferrite nanoparticles have been regarded as one of the competitive candidates because of their suitable physical, chemical and magnetic properties like the high anisotropy constant, high coercivity and high Curie temperature, moderate saturation magnetization and ease of synthesis. This paper introduces the magnetic properties, synthesis methods and some medical applications, including the hyperthermia, magnetic resonance imaging (MRI), magnetic separation and drug delivery of cobalt ferrite nanoparticles. Highlights: ► Cobalt ferrite nanoparticles are one of the most important materials for nanomedicine. ► They have high coercivity and moderate saturation magnetization. ► Cobalt ferrite nanoparticles are synthesized easily. ► They are a good candidate for hyperthermia and magnetic resonance imaging.

The role of cobalt ferrite magnetic nanoparticles in medical science

Energy Technology Data Exchange (ETDEWEB)

Amiri, S.; Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir

2013-01-01

The nanotechnology industry is rapidly growing and promises that the substantial changes that will have significant economic and scientific impacts be applicable to a wide range of areas, such as aerospace engineering, nano-electronics, environmental remediation and medical healthcare. In this area, cobalt ferrite nanoparticles have been regarded as one of the competitive candidates because of their suitable physical, chemical and magnetic properties like the high anisotropy constant, high coercivity and high Curie temperature, moderate saturation magnetization and ease of synthesis. This paper introduces the magnetic properties, synthesis methods and some medical applications, including the hyperthermia, magnetic resonance imaging (MRI), magnetic separation and drug delivery of cobalt ferrite nanoparticles. Highlights: Black-Right-Pointing-Pointer Cobalt ferrite nanoparticles are one of the most important materials for nanomedicine. Black-Right-Pointing-Pointer They have high coercivity and moderate saturation magnetization. Black-Right-Pointing-Pointer Cobalt ferrite nanoparticles are synthesized easily. Black-Right-Pointing-Pointer They are a good candidate for hyperthermia and magnetic resonance imaging.

Retention of Radionuclides in Halite and Anhydrite

DEFF Research Database (Denmark)

Carlsen, Lars; Platz, O.

1986-01-01

The interaction between a series of radionuclides, comprising **1**3**4Cs** plus , **8**5Sr**2** plus , **6**0Co**2** plus , **1**5**4Eu**3** plus , **2**4**1Am**3** plus , and **9**9Tc (as TcO//4** minus ) and halite (NaCl) and anhydrite (CaSO//4), respectively, has been investigated. It appears...... for europium and americium, respectively. Impuritites in the halite, such as hematite or anhydrite strongly increase the sorption efficiency. In these cases also cobalt, and to a minor extent cesium and strontium, was found to be sorbed. Anhydrite was found to sorb all metal cations studied. The sorption...

Cobalt release from inexpensive jewellery

DEFF Research Database (Denmark)

Thyssen, Jacob Pontoppidan; Jellesen, Morten Stendahl; Menné, Torkil

2010-01-01

. Conclusions: This study showed that only a minority of inexpensive jewellery purchased in Denmark released cobalt when analysed with the cobalt spot test. As fashion trends fluctuate and we found cobalt release from dark appearing jewellery, cobalt release from consumer items should be monitored in the future......Objectives: The aim was to study 354 consumer items using the cobalt spot test. Cobalt release was assessed to obtain a risk estimate of cobalt allergy and dermatitis in consumers who would wear the jewellery. Methods: The cobalt spot test was used to assess cobalt release from all items...

Observation of migrating superoxide species in YBa2Cu3(57Co)O7-δ

International Nuclear Information System (INIS)

Kopelev, N.; Chechersky, V.; Tian Jing; Homonnay, Z.; Wei Yen; Nath, A.

1992-01-01

The interaction of the migrating superoxide ion O 2 - with the central cobalt-57 atom of the four coordinate species at the chain site is probed with the help of emission Moessbauer spectroscopy. The bond formation between 57 Co and O 2 - requires some thermal activation, and consequently the five-coordinate species is stable only above ∝350 K. The equilibrium shifts in its favor at higher temperatures, and the interconversion between the two species is completely reversible. The O 2 - ion can either attach to cobalt end-on with one of the oxygen atoms or interact equivalently with both. The amount of the five-coordinate species formed seems to be limited by the availability of O 2 - . The interconversion ceases to occur after a prolonged thermal treatment of the YBa 2 Cu 3 ( 57 Co)O 7-δ pellet at 420degC under argon flow. All the interstitial oxygen species are presumably removed without any measurable loss of oxygen from the Cu-O chains. (orig.)

Self-powered in-core detectors of cobalt type

International Nuclear Information System (INIS)

Jonsson, Georg

1975-01-01

Testing and development of self-powered neutron detectors with a cobalt emitter is described. Long term irradiation at 400 deg C is expected to indicate insulation quality, change in calibration and 60 Co build-up. Dynamic tests to investigate possible transient effects due to temperature changes are being performed on a number of detectors up to about 600 deg C. A long term irradiation at low temperature has been terminated after 4.5 years. On completion, neutron dose was estimated to be 5.6 x 10 21 nvt and the 60 Co background was 9.3 % of the full flux signal. A recently introduced long term test is expected to provide data on instability effects due to 61 Co. For a BWR in-core detector installation, the main advantage of cobalt detectors, apart from the small size, appears to be long life. Development work is being done on detectors with vanadium-cobalt emitters, electronic separation of fast and delayed signals and reduction of gamma sensitivity. (O.T.)

Removal of some radionuclides from water by bioaccumulation

International Nuclear Information System (INIS)

Miskovic, D.; Conkic, L.; Dalmacija, B.; Gantar, M.

1992-01-01

First objective of this study was to investigate the application of biologically activated carbon (BAC) as well as its comparison to adsorption, with the aim of removing some radionuclides from water. The isotopes Cs 134 and Cs 137 were bioaccumulated by BAC up to 50%, while the I 131 isotope was only physicochemically adsorbed (about 40%). Also, the process of radionuclides (Cs 137 , Ce 139 , Co 57 , Co 60 ) fixation on blue-green algae (Nostoc sp.) was investigated. The kinetics of the removal of these radionuclides from water was recorded. It was found that after a contact period of about half an hour 40-70% of the activity was removed. (Author)

High performance liquid chromatographic determination of vanadium in crude oils and cobalt and iron in pharmaceutical preparations

International Nuclear Information System (INIS)

Khuhawar, M.Y.; Lanjwani, S.N.; Khaskhely, G.Q.

1993-01-01

High performance liquid Chromatographic (HPLC) method has ben developed for the determination of vanadium in crude oils, based on acid decomposition of oils, followed by complexation with bis (salicylaldehyde) tetramethyl ethylenediamine (H2SA2Ten). The complex is extracted in organic phase and is separated from copper and nickel using normal phase HPLC column. Detection is achieved using spectrophtmetric detector. The vanadium in oil is obtained at sub microgram/g level. Similarly cobalt(II), cobalt(III) and iron(II) are separated on reversed phase HPLC column. Pre column derivatization is used to develop HPLC method for the determination of cobalt and iron in pharmaceutical preparations. Finally results are compared using atomic absorption spectrometer. (author)

Uptake of cesium and cobalt radionuclides from simulated radioactive wastewater by Ludwigia stolonifera aquatic plant

Energy Technology Data Exchange (ETDEWEB)

Saleh, H.M., E-mail: hosamsaleh70@yahoo.com [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Bayoumi, T.A. [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Mahmoud, H.H. [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt); Central Laboratory for Elemental and Isotopic Analysis, Nuclear Research Center, Atomic Energy Authority (Egypt); Aglan, R.F. [Department of Analytical Chemistry, Hot Laboratories Center, Atomic Energy Authority, 13759 (Egypt)

2017-04-15

Highlights: • Radioactive contamination is a serious environmental problem. • Phytoremediation is a proper technique for soil and water decontamination. • Aquatic plant, Ludwigia stolonifera, for bioaccumulation of radionuclides. • Factors affecting uptake efficiency of {sup 137}Cs and {sup 60}Co radionuclides. - Abstract: The article reported herein was conducted as part of comprehensive study considered to evaluate the efficiency of Ludwigia stolonifera as a local aquatic plant located in the Egyptian environment for phytoremediation of hazardous toxic and radioactive elements dissolved in aqueous wastes dispersed from industrial and urban applications through the human activities. Ludwigia stolonifera was immersed in single and binary solution of {sup 60}Co and {sup 137}Cs. The specific uptake rate of plant was determined at various activity contents of radionuclides, multiplied masses of plant, lighting exposure and different pH values. Accumulation of {sup 60}Co and {sup 137}Cs in mixture was more than 95% and 65% respectively. pH was less effective than the other evaluated parameters.

Adsorption of Cesium, Strontium, and Rubidium radionuclides in the Mag-molecular process: The influence of important factors

Directory of Open Access Journals (Sweden)

Fatemeh Tangestani

2017-09-01

Full Text Available In this study, the adsorption of cesium, strontium, and rubidium radionuclides by ferritin magmolecules in a batch system was investigated under different experimental conditions. The experiments were conducted in a pilot plant that involved the contactor unit and the magnetic separator unit. The impact of the pollutant concentrations, adsorbent concentration, and pH on the efficiency of the process were investigated thoroughly. The maximum recovery of radionuclides in the studied domain were 57.05%, 85.42% and 71.82% for Cs+, Sr2+ and Rb+ ,respectively, in which the pollutant concentration was 363.63 mg/l, the adsorbent concentration was 0.011 g/l, and the pH was 7.5. The results showed that the ferritin adsorbent in the magmolecular process manifested a higher efficiency in adsorbing the bivalent ions of strontium compared to the univalent ions of cesium and rubidium. Furthermore, the results were statistically analyzed and the model and residual plots of each radionuclide were presented. The results also signified  relationships between the independent variables and recovery.

Speciation of radionuclides in the environment

International Nuclear Information System (INIS)

Gunten, H.R. von; Benes, P.

1994-02-01

Methods for the determination of the speciation of radionuclides in aerosols, in aquatic solutions, in sediments, soils and rocks are reviewed. At present, most of the results about speciation are deduced from model calculations, model experiments, and separation of species (forms) of radionuclides, e.g., by sequential extraction procedures. Methods of direct determination of speciation of radionuclides (e.g. by laser induced spectroscopy) are in general not yet sensitive enough for a measurement of the very low concentrations of radionuclides in the environment. The methodological part of this paper is followed by a review of the very abundant literature about speciation of important radionuclides in the environment, i.e. in the atmosphere, hydrosphere and lithosphere. The review does not include the biosphere. Literature up to spring 1993 is included (with a few more recent additions). (author)

Cobalt release from inexpensive jewellery: has the use of cobalt replaced nickel following regulatory intervention?

Science.gov (United States)

Thyssen, Jacob Pontoppidan; Jellesen, Morten S; Menné, Torkil; Lidén, Carola; Julander, Anneli; Møller, Per; Johansen, Jeanne Duus

2010-08-01

Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure. The aim was to study 354 consumer items using the cobalt spot test. Cobalt release was assessed to obtain a risk estimate of cobalt allergy and dermatitis in consumers who would wear the jewellery. The cobalt spot test was used to assess cobalt release from all items. Microstructural characterization was made using scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). Cobalt release was found in 4 (1.1%) of 354 items. All these had a dark appearance. SEM/EDS was performed on the four dark appearing items which showed tin-cobalt plating on these. This study showed that only a minority of inexpensive jewellery purchased in Denmark released cobalt when analysed with the cobalt spot test. As fashion trends fluctuate and we found cobalt release from dark appearing jewellery, cobalt release from consumer items should be monitored in the future. Industries may not be fully aware of the potential cobalt allergy problem.

Extracts from the 1995/96 European intercomparison of in vivo monitoring systems - a means of comparing the performance of Nal detectors with Ge detectors?

Energy Technology Data Exchange (ETDEWEB)

Hunt, E.L.; Thieme, M.; Koenig, K.; Schmitt-Hannig, A.; Goedde, R.; Ruehm, W. [Bundesamt fuer Strahlenschutz, Oberschleissheim (Germany). Inst. fuer Strahlenhygiene

1997-12-01

Between August 1995 and July 1996 a Europeanwide intercomparison of 44 whole body counters took place with a number of 42 participating institutions from 19 European countries. A tissue-equivalent whole body phantom containing the radionuclides potassium-40, cobalt-57, cobalt-60 and caesium-137 with activities between 1 to 4 kBq was transported by a representative of the Bundesamt fuer Strahlenschutz (German Federal Office of Radiation Protection) to each of the participating laboratories. The phantom was there treated like a human subject during routine measurement and the participants were asked to identify the incorporated radionuclides and quantify their respective activities. The paper describes the measurement programme and the phantom used. The results are discussed with respect to detector type. (orig.)

Labeled bleomycin as a tumor localizing agent

International Nuclear Information System (INIS)

Vos, C.M.

1982-01-01

The antitumor antibiotics bleomycins labeled with 57 Co are known to possess excellent tumor localizing properties but the rather long halflife of 57 Co prevents its use in clinical routine. It is therefore desirable to label cobalt-bleomycin with a more suitable radionuclide, e.g. 123 I. This thesis reports on further studies on cobalt-bleomycin. It appears from the studies on the structure of cobalt-bleomycin described in this thesis (Chapter B), that cobalt is able to form different complexes with bleomycin (the forms I and II). The difference in structure is not clear, but the biological behavior of both forms is studied (Chapter C). In Chapter D the iodination of cobalt-bleomycin is described. Iodination of free bleomycin yields a product with bad tumor localizing properties, and straight-on iodination of cobalt-bleomycin is prevented by the presence of cobalt. To retain the good tumor-localizing properties of cobalt-bleomycin, possibilities were explored to incorporate the iodine in the terminal amine (a side chain, not involved in complexation). Alkylation of cobalt-bleomycin demethyl A 2 with N-bromoacetyl-3-iodoaniline yielded a product; unfortunately this product possessed bad tumor localizing properties and moreover, was not stable in vivo. The structure of a possibly successful iodinated cobalt-bleomycin is outlined but could not be realized during this research. (Auth.)

Cobalt release from implants and consumer items and characteristics of cobalt sensitized patients with dermatitis

DEFF Research Database (Denmark)

Thyssen, Jacob Pontoppidan; Menne, Torkil; Liden, Carola

2012-01-01

-containing dental alloys and revised hip implant components.Results. Six of eight dental alloys and 10 of 98 revised hip implant components released cobalt in the cobalt spot test, whereas none of 50 mobile phones gave positive reactions. The clinical relevance of positive cobalt test reactions was difficult......-tested dermatitis patients in an attempt to better understand cobalt allergy.Materials and methods. 19 780 dermatitis patients aged 4-99 years were patch tested with nickel, chromium or cobalt between 1985 and 2010. The cobalt spot test was used to test for cobalt ion release from mobile phones as well as cobalt...

New radionuclide generator systems for use in nuclear medicine

International Nuclear Information System (INIS)

Atcher, R.W.

1979-01-01

A current emphasis in nuclear medicine is to better match the physical lifetime of the radionuclides used in vivo for diagnosis and treatment to the biological lifetime of the diagnostic procedure or to minimize radiation dose to areas other than those to be treated. In many cases the biological lifetime is on the order of minutes. Since the direct production of radionuclides with half lives of minutes requires the user to be near a suitable reactor or accelerator, this study was undertaken to produce short-lived radionuclides indirectly. If a long-lived radionuclide decays into a short-lived radionuclide, quick separation of the daughter activity from the parent enables the user to have a short-lived daughter while freeing him from the constraint of proximity to a cyclotron. Systems where a short-lived daughter is separated from a long-lived parent are called radionuclide generators. Two generator systems were developed for use in nuclear medicine, one in diagnostic work and the other for therapeutic work. The yield and breakthrough characteristics were within the limits required to minimize unnecessary radiation exposure in patients. Two parent radionuclides were produced using 4 He beams available from medium energy cyclotrons. The yield was high enough to produce generators that would be useful in clinical applications

Method for separation of Cs from acid solution dissolving radionuclides and microanalysis of solution with ICP-AES

International Nuclear Information System (INIS)

Kanazawa, Toru; Hidaka, Akihide; Kudo, Tamotsu; Nakamura, Takehiko; Fuketa, Toyoshi

2004-06-01

The VEGA (Verification Experiments of radionuclides Gas/Aerosol release) program is being performed at JAERI to understand mechanisms of radionuclides release from irradiated fuel during severe accidents. As a part of evaluation in the program, the mass balances of released and deposited FP (Fission Products) onto the test apparatus are estimated from gamma ray measurement for acid solution leached from the apparatus, but short-life nuclides are difficult to be measured because those in the VEGA fuel have been mostly depleted due to cooling for several years. Moreover, the radionuclides without emitting gamma rays and very small quantity of elements cannot be quantified by gamma ray measurement. Therefore, a microanalysis by ICP-AES (Inductively Coupled Plasma - Atomic Emission Spectrometry) for the acid solution leached from VEGA apparatuses is being applied to evaluate the released and deposited masses for those elements. Since Cs-134 and -137, which are major FP dissolved in the solution, have high intensity of gamma ray spectrum, they have to be removed from the solution before the microanalysis in order to avoid contamination of ICP system and to decrease exposure to gamma ray. In this report, methods for separation of Cs from acid solution were reviewed and the applicability of them to the ICP-AES analysis was discussed. The method for Cs separation using the inorganic ion exchanger, AMP (Ammonium Molybdate Phosphate) was applied to the solutions of cold and hot test and the effectiveness was examined. The results showed that more than 99.9% of Cs could be removed from the test solutions, and once removed Sb by AMP was recovered by using a complexing agent such as citric acid. Next, the method was applied to an acid solution leached from VEGA-3 apparatus, and ICP-AES analysis was performed for it. The analysis showed that amount of U, Sr and Zr were successfully quantified. Most of elements to be analyzed were measurable except for Sb, Ag and Sn, although

Radionuclides in radiation-induced bystander effect; may it share in radionuclide therapy?

Science.gov (United States)

Widel, M

2017-01-01

For many years in radiobiology and radiotherapy predominated the conviction that cellular DNA is the main target for ionizing radiation, however, the view has changed in the past 20 years. Nowadays, it is assumed that not only directed (targeted) radiation effect, but also an indirect (non-targeted) effect may contribute to the result of radiation treatment. Non-targeted effect is relatively well recognized after external beam irradiation in vitro and in vivo, and comprises such phenomena like radiation-induced bystander effect (RIBE), genomic instability, adaptive response and abscopal (out of field) effect. These stress-induced and molecular signaling mediated phenomena appear in non-targeted cells as variety responses resembling that observed in directly hit cells. Bystander effects can be both detrimental and beneficial in dependence on dose, dose-rate, cell type, genetic status and experimental condition. Less is known about radionuclide-induced non-targeted effects in radionuclide therapy, although, based on characteristics of the radionuclide radiation, on experiments in vitro utilizing classical and 3-D cell cultures, and preclinical study on animals it seems obvious that exposure to radionuclide is accompanied by various bystander effects, mostly damaging, less often protective. This review summarizes existing data on radionuclide induced bystander effects comprising radionuclides emitting beta- and alpha-particles and Auger electrons used in tumor radiotherapy and diagnostics. So far, separation of the direct effect of radionuclide decay from crossfire and bystander effects in clinical targeted radionuclide therapy is impossible because of the lack of methods to assess whether, and to what extent bystander effect is involved in human organism. Considerations on this topic are also included.

Experimental investigation of cobalt-60 accumulation and elimination in Cyprinus carpio (L.)

International Nuclear Information System (INIS)

Fritsch, A.F.

1985-11-01

When introduced in cation form, 60 Co showed a distinct tendency to form anion or neutral complexes (50% and 20%, respectively); this was favorized by a high biomass content per liter of water. The ionic evolution of the radionuclide did not affect its accumulation level in the fish. Direct contamination predominated (70%) and the concentration factor at equilibrium was 10. Nutritional transfer from Limnaea to carp, after ingestion of 45 contaminated rations in 63 days, resulted in a low radionuclide retention factor (3 x 10 -3 ) that was not subject to bioamplification. Cobalt-60 was primarily eliminated via urine (60%), while the fecal matter contained only 20% of the radioactive isotope ingested in the food. The 60 Co content of carp contaminated from the water increased proportionally with the temperature. However, the 60 Co concentration did not vary significantly with the thermal factor, and the radionuclide concentration factor ranged from 4 to 6 between 8 0 C and 25 0 C. Decontamination was generally a two-phase process characterized by a short biological half-life ( 60 Co contained in the fish. The high 60 Co content of the digestive tract may be explained by fecal excretion of the radioactive isotope (30-40% of the elimination). The kidneys act as radionuclide elimination regulators via the urinary system [fr

Removal of some radionuclides from water by bioaccumulation

Energy Technology Data Exchange (ETDEWEB)

Miskovic, D.; Conkic, L.; Dalmacija, B.; Gantar, M. (Trg D. Obradvica 3, Novi Sad (Yugoslavia). Faculty of Sciences)

1992-01-01

First objective of this study was to investigate the application of biologically activated carbon (BAC) as well as its comparison to adsorption, with the aim of removing some radionuclides from water. The isotopes Cs[sup 134] and Cs[sup 137] were bioaccumulated by BAC up to 50%, while the I[sup 131] isotope was only physicochemically adsorbed (about 40%). Also, the process of radionuclides (Cs[sup 137], Ce[sup 139], Co[sup 57], Co[sup 60]) fixation on blue-green algae (Nostoc sp.) was investigated. The kinetics of the removal of these radionuclides from water was recorded. It was found that after a contact period of about half an hour 40-70% of the activity was removed. (Author).

Separation and preconcentration of lead(II), cobalt(II), and nickel(II) on EDTA immobilized activated carbon cloth prior to flame atomic absorption spectrometric determination in environmental samples

OpenAIRE

ALOTHMAN, ZEID ABDULLAH; YILMAZ, ERKAN; HABİLA, MOHAMED; SOYLAK, MUSTAFA

2015-01-01

The synthesis and characterization of ethylenediaminetetraacetic acid immobilized activated carbon cloth was performed in the present work. It was used for preconcentration-separation of lead(II), cobalt(II), and nickel(II) at trace levels as an adsorbent. Factors including pH, concentration and volume of eluent, sample and eluent flow rates, sample volume, and effect of coexisting ions on the solid phase extraction of analytes were examined. The preconcentration factor was 50. The detection ...

Distribution of six radionuclides between soluble and particulate phase at the sea-freshwater interface

International Nuclear Information System (INIS)

Peres, J.M.

1984-01-01

The distribution of the soluble and particulate phases of radionuclides has been studied in water samples of various salinities (0 per mill; 3.8 per mill; 7.6 per mill; 15.2 per mill; 22.8 per mill; 30.4 per mill; 34 per mill). Cesium 137, cobalt 60, manganese 54, zinc 65, chromium 51 and sodium 22 were investigated. The results are expressed as retention percentages or distribution coefficients (Kd). Increased salinities resulted in decreased retention rates varying with the radionuclides; this appeared with the lowest salinities, and the evolution was small beyond 7 per mill. Other parameters were considered beside salinity, viz.: the suspended matter characteristics (mineralogy, particle size distribution); particulate load of water; organic content, whether associated to the soluble or particulate phase; physico-chemical forms of the radionuclides. To determine the particle size spectra of the suspended matter in the experimental samples, a laser granulometer was used [fr

A quality control exercise of radionuclide calibrators among Belgian hospitals

International Nuclear Information System (INIS)

Reher, D.F.G.; Merlo, P.

1990-01-01

On the initiative of the Belgian Association of Hospital Physicists, eleven Belgian hospitals participated in a quality control of radionuclide calibrators conducted in collaboration with the Central Bureau for Nuclear Measurements of the Commission of the European Communities. For practical reasons the nuclide 57 Co was chosen. The results from 20 different radionuclide calibrators show a fair agreement with a similar comparison carried out in 1980 in the UK. (orig.)

Solvent for the simultaneous recovery of radionuclides from liquid radioactive wastes

Science.gov (United States)

Romanovskiy, Valeriy Nicholiavich; Smirnov, Igor V.; Babain, Vasiliy A.; Todd, Terry A.; Brewer, Ken N.

2002-01-01

The present invention relates to solvents, and methods, for selectively extracting and recovering radionuclides, especially cesium and strontium, rare earths and actinides from liquid radioactive wastes. More specifically, the invention relates to extracting agent solvent compositions comprising complex organoboron compounds, substituted polyethylene glycols, and neutral organophosphorus compounds in a diluent. The preferred solvent comprises a chlorinated cobalt dicarbollide, diphenyl-dibutylmethylenecarbamoylphosphine oxide, PEG-400, and a diluent of phenylpolyfluoroalkyl sulfone. The invention also provides a method of using the invention extracting agents to recover cesium, strontium, rare earths and actinides from liquid radioactive waste.

Determination of long-lived radionuclides in environment

International Nuclear Information System (INIS)

Seki, Riki

2001-01-01

This review summarized the recent papers published after 1985, because Higuchi had written 'Radiometry in Environment' for Advanced Review in this journal, 1985. Separation, purification and measurement method of long-lived radionuclide without light elements are reported. To determine radionuclide in the environment, a pretreatment of sample such as enrichment and separation is need. An extraction chromatography and adsorbents, for example, active carbon and AMP, were developed for the above objects. For analysis of low level radionuclide, background was decreased. ICP-MS, RIMS (Resonance Ionization Mass Spectroscopy) and AMS were used to determine mass of long-lived ones. ICP-MS can measure 93 Zr, 99 Tc, 107 Pd, 129 I and 135 Cs in the radioactive waste without a chemical analysis. RIMS determined 41 Ca, 236-244 Pu, 90 Sr and 237 Np. AMS showed good results for pure beta emitter nuclides ad trace long-lived radionuclide, for example, 14 C, 10 Be, 26 Al, 36 Cl, 129 I and 236 U. Measurement method and results of 14 C, 10 Be, 26 Al, 36 Cl, 41 Ca, 63 Ni, 79 Se, 85 Kr, 99 Tc, 129 I, 237 Np and Pu were explained. (S.Y.)

Radionuclide table. Pt. 1

International Nuclear Information System (INIS)

Legrand, Jean; Perolat, J.-P.; Lagoutine, Frederic; Le Gallic, Yves.

The evaluation of the following 29 radionuclides is presented: 22 Na, 24 Na, sup(24m)Na, 51 Cr, 54 Mn, 57 Co, 58 Co, sup(58m)Co, 60 Co, sup(60m)Co, 75 Se, 103 Ru, sup(103m)Rh, sup(110m)Ag- 110 Ag, 109 Cd, 125 Sb, sup(125mTe), 125 I, 133 Xe, sup(133m)Xe, 131 Cs, 134 Cs, sup(134m)Cs, 139 Ce, 144 Ce- 144 Pr, 144 Pr, 169 Er, 186 Re, 203 Hg. The introduction contains a brief description of radioactive processes and the evaluation rules followed. The best values and associated uncertainties are given for each radionuclide for the major parameters of the decay scheme and the radiation intensities emitted, together with a decay table. Gamma, X-rays and sometimes conversion electron spectra are also provided [fr

Passivation and corrosion behaviours of cobalt and cobalt-chromium-molybdenum alloy

International Nuclear Information System (INIS)

Metikos-Hukovic, M.; Babic, R.

2007-01-01

Passivation and corrosion behaviour of the cobalt and cobalt-base alloy Co30Cr6Mo was studied in a simulated physiological solution containing chloride and bicarbonate ions and with pH of 6.8. The oxido-reduction processes included solid state transformations occurring at the cobalt/electrolyte interface are interpreted using theories of surface electrochemistry. The dissolution of cobalt is significantly suppressed by alloying it with chromium and molybdenum, since the alloy exhibited 'chromium like' passivity. The structural and protective properties of passive oxide films formed spontaneously at the open circuit potential or during the anodic polarization were studied using electrochemical impedance spectroscopy in the wide frequency range

Determination of C0-60 in Cobalt Slugs and Slabs and Radionuclides in Curium Sampler Slugs L-Reactor Disassembly Basin

International Nuclear Information System (INIS)

Casella, V.R.

2004-01-01

Co-60 was historically produced in the SRS reactors. Cobalt slugs were irradiated in the early 1970s. Post-production, remaining cobalt slugs (including slab form) were consolidated for storage. There are approximately nine hundred cobalt slugs currently stored awaiting final disposition. These slugs had historically incomplete documentation for activity rates; therefore, assaying was required in order to determine their activity levels. Since the gamma dose rate from these slugs is extremely high, the most cost effective way to shield a source of this magnitude from personnel and the radiation detector was to use the basin water in which the slugs are stored as the shield. A sodium iodide gamma detector was placed above a specially designed air collimator assembly, so that slug was at least eight feet from the detector and was shielded by the basin water. Using a sodium iodide detector and multichannel analyzer system and an underwater collimator assembly, Co-60 concentrations we re determined for Disassembly Basin cobalt slugs and slabs and 18 curium sampler slugs. The total activity of all of the assayed slugs summed to 31,783 curies. From the Co-60 concentrations of the curium sampler slugs, the irradiation flux was determined for the known irradiation time. The amounts of Pu-238, 239, 240, 241, 242; Am-241, 243; and Cm-242, 244 produced were then obtained based on the original amount of Pu-239 irradiated

Purification of radionuclides for nuclear medicine: The multicolumn selectivity inversion generator concept

International Nuclear Information System (INIS)

Horwitz, E.P.; Bond, A.H.

2003-01-01

A new radionuclide generator system has been developed and demonstrated for the production of 212 Bi from 224 Ra/ 212 Pb and for 90 Y from 90 Sr. The new concept, called a Multicolumn Selectivity Inversion Generator, involves the selective retention of the desired daughter radionuclide from a solution of the parent or parents by a primary separation column followed by stripping the daughter radionuclide from the primary column, and immediately without feed adjustment, passing the daughter through a secondary separation (guard) column that retains the parents while the daughter elutes unrestrained. The new generator system minimises the effects of radiation damage to the support material permitting the reliable production of nuclides of high chemical and radionuclidic purity. (author)

[Cost-benefit of the Schilling test using cobalt-57].

Science.gov (United States)

Arteaga de Murphy, C; Maisterrena, J; Labardini, J; Ruiz, A; Luviano, C

1991-01-01

Our purpose in the present publication is to determine the cost-benefit relation of the Schilling test used to measure the intestinal absorption of radioactive vitamin B12. The 60Co-B12 urinary excretion Schilling test was first reported in 1953, and five years later it was being performed at the National Institute of Nutrition (INNSZ) in Mexico City. It was performed in its original version until 1969 and from 1970 to 1980, the direct absorption was measured with a whole-body counter. For the last nine years we have used the Schilling test with 57Co labeled cyanocobalamin. From January 1981 through March 1990, 240 of these tests were carried out in 120 patients. The results were tabulated and compared with their clinical diagnosis. We analyzed our laboratory and labor costs. An oral dose of 0.5 micrograms of vitamin B12 labelled with 18.5 Bq of 57Co is taken by the fasting patients and two hours later one mg of standard B12 vitamin is injected. Urine is collected for 48 hours and the radioactivity is measured in a scintillation counter. Three days later the test is repeated with an additional oral dose of intrinsic factor (IF). The total expense is calculated using the following factors: the cost of the imported radioactive vitamin, IF capsules, parenteral B12 vitamin, syringes, equipment use and its depreciation, laboratory material, and salaries for the professional and administrative personnel.(ABSTRACT TRUNCATED AT 250 WORDS)

An application of clonal Japanese flounder, paralichthys olivaceus to the experiment on bioaccumulation of radionuclides

International Nuclear Information System (INIS)

Miyazaki, Taeko; Nakahara, Motokazu; Nakamura, Ryoichi; Hirano, Shigeki; Watabe, Teruhisa; Yamamoto, Eiichi

2000-01-01

A laboratory experiment of accumulation and excretion of radionuclides ( 125 I, 57 Co, 141 Ce, 103 Ru, 85 Sr, 137 Cs, 54 Mn) in juvenile Japanese flounder was carried out in order to elucidate the genetic factor intervening in the mineral balance, which possibly caused the fluctuation of so-called concentration factors. Fish originating from two populations, namely clone brood and hatchery-reared brood, were used in the present study. The variance of concentration of radionuclides was compared in terms of the radionuclides activity ratio, which was defined by radionuclide concentration in fish normalized by that in surrounding water. In general, narrower variations of concentration were observed in clone brood than in hatchery-reared brood, and significant differences were observed for 57 Co, 141 Ce and 137 Cs in the accumulation process and for five radionuclides other than 125 I and 103 Ru in excretion process. The present study suggested that a probability of application of clonal fish would be advantageous in experimental assessments of biological effects of environmental contaminants in the sea. (author)

Multi-column step-gradient chromatography system for automated ion exchange separations

International Nuclear Information System (INIS)

Rucker, T.L.

1985-01-01

A multi-column step-gradient chromatography system has been designed to perform automated sequential separations of radionuclides by ion exchange chromatography. The system consists of a digital programmer with automatic stream selection valve, two peristaltic pumps, ten columns, and a fraction collector. The automation allows complicated separations of radionuclides to be made with minimal analyst attention and allows for increased productivity and reduced cost of analyses. Results are reported for test separations on mixtures of radionuclides by the system

Moessbauer spectroscopic studies of the chemical effects associated with 57Co(electron capture)57Fe decay in tris-β-diketonatocobalt(III) compounds

International Nuclear Information System (INIS)

Sakai, Yoichi; Endo, Kazutoyo; Sano, Hirotoshi

1980-01-01

Magnetic hyperfine structures (hfs) were found in the absorption Moessbauer spectra at 78 K of a paramagnetic iron(III) complex diluted in a diamagnetic cobalt(III) or aluminium(III) complex such as 57 Fe(acac) 3 in Co(acac) 3 , 57 Fe(oxin) 3 in Al(oxin) 3 , and 57 Fe(dbm) 3 in Co(dbm) 3 (acac=acetylacetonato, oxin=8-quinolinolato, and dbm=dibenzoylmethanato), showing that the magnetic hfs is caused by the spin-spin relaxation through the surrounding diamagnetic species. In the emission Moessbauer experiments, magnetic hfs was observed at 78 K in 57 Co-labelled Co(dbm) 3 , Co(oxin) 3 , and polystyrene-diluted Co(acac) 3 , while it was not observed in 57 Co-labelled Co(acac) 3 and Co(dpm) 3 (dpm=dipivaloylmethanato). The former possess pi -conjugated systems to a greater extent than the latter, either in the ligands or in the vicinity of the 57 Co-labelled Co(III) species. These results were explained in terms of the radiolytic stabilities of the matrices as well as those of 57 Co-labelled compounds by showing that the paramagnetic radicals produced in a diamagnetic matrix quench the magnetic hfs because of the increased spin-spin interaction, as a consequence of the local radiolysis by EC-decay. (author)

Elicitation threshold of cobalt chloride

DEFF Research Database (Denmark)

Fischer, Louise A; Johansen, Jeanne D; Voelund, Aage

2016-01-01

: On the basis of five included studies, the ED10 values of aqueous cobalt chloride ranged between 0.0663 and 1.95 µg cobalt/cm(2), corresponding to 30.8-259 ppm. CONCLUSIONS: Our analysis provides an overview of the doses of cobalt that are required to elicit allergic cobalt contactdermatitis in sensitized...

Method of preparing radionuclide doses

International Nuclear Information System (INIS)

Kuperus, J.H.

1987-01-01

A method is described of preparing aliquot dosea of a tracer material useful in diagnostic nuclear medicine comprising: storing discrete quantities of a lyophilized radionuclide carrier in separate tubular containers from which air and moisture is excluded, selecting from the tubular containers a container in which is stored a carrier appropriate for a nuclear diagnostic test to be performed, interposing the selected container between the needle and the barrel of a hypodermic syringe, and drawing a predetermined amount of a liquid containing a radionuclide tracer in known concentration into the hypodermic syringe barrel through the hypodermic needle and through the selected container to dissolve the discrete quantity of lyophilized carrier therein to combine the carrier with the radionuclide tracer to form an aliquot dose of nuclear diagnostic tracer material, as needed

The separation of radionuclide migration by solution and particle transport in LLRW repository buffer material

International Nuclear Information System (INIS)

Torok, J.; Buckley, L.P.; Woods, B.L.

1989-01-01

Laboratory-scale lysimeter experiments were performed with simulated waste forms placed in candidate buffer materials which have been chosen for a low-level radioactive waste repository. Radionuclide releases into the effluent water and radionuclide capture by the buffer material were determined. The results could not be explained by traditional solution transport mechanisms, and transport by particles released from the waste form and/or transport by buffer particles were suspected as the dominant mechanism for radionuclide release from the lysimeters. To elucidate the relative contribution of particle and solution transport, the waste forms were replaced by a wafer of neutron-activated buffer soaked with selected soluble isotopes. Particle transport was determined by the movement of gamma-emitting neutron-activation products through the lysimeter. Solution transport was quantified by comparing the migration of soluble radionuclides relative to the transport of neutron activation products. The new approach for monitoring radionuclide migration in soil is presented. It facilitates the determination of most of the fundamental coefficients required to model the transport process

Thermodynamic equilibrium model to predict the cobalt distribution coefficient in the CoCl2--HCl--H2O--TBP liquid--liquid extraction system

International Nuclear Information System (INIS)

Nevarez, M.; Bautista, R.G.

1976-01-01

The development of a thermodynamic equilibrium model to predict the cobalt distribution coefficient in the CoCl 2 -HCl-H 2 O-TBP system is described. The model makes use of the various aqueous phase cobaltous chloride complexes stoichiometric stability constants expressed as their degree of formation, their mechanism of extraction into the organic phase, and the equilibrium constant for the extraction reaction. The model was verified by the good agreement between the calculated cobalt distribution coefficients and those obtained experimentally both in the present study and published by other investigators. The optimum extraction of cobalt by the TBP occurred at an HCl equilibrium aqueous place concentration between 8.5 and 9.5M. The development of efficient procedures for the separation and concentration of important industrial metals from their aqueous solutions by liquid-liquid extraction has recently been given impetus by the realization of an impending shortage of energy and mineral resources. Liquid-liquid extraction is one of the few methods by which it is possible to quantitatively separate elements which are similar in properties. The use of liquid-liquid extraction to separate cobalt and nickel, which very frequently occur in nature together, is an important separation problem in nonferrous metallurgy. There is some fundamental information available in the chemical literature regarding the mechanism and equilibrium thermodynamic properties of selected liquid-liquid extraction systems. This research effort shows how this available information can be utilized to improve existing separation and concentration theory and technique. The development and application of a thermodynamic equilibrium model for describing the liquid-liquid extraction of cobaltous chloride from aqueous HCl solutions by tributyl phosphate (TBP) using experimental data obtained in this investigation and from the literature are presented

The effect of organic amendment on mobility of cesium in tropical soils - The effect of organic amendment on sorption mechanisms for cesium and cobalt in tropical soils

Energy Technology Data Exchange (ETDEWEB)

Wasserman, M.A.V.; Santos-Oliveira, R. [Instituto de Engenharia nuclear/CNEN. Rua Helio de Almeida, 75. Cidade Universitaria - Ilha do Fundao, Rio de Janeiro, RJ. CEP 21941-906 (Brazil); Garcia, R.J.L.; Ferreira, A.C.M.; Rochedo, E.R.R.; Sobrinho, G.A.N. [Instituto de Radioprotecao e Dosimetria/CNEN. Av. Salvador Allende s /no. Rio de Janeiro, RJ. CEP: 22780-160 (Brazil); Perez, D.V. [Centro Nacional de Pesquisa de Solos/EMBRAPA. R. Jardim Botanico, 1024.Rio de Janeiro, RJ, CEP: 22460-000 (Brazil); Wasserman, J.C. [dUFF Network of Environment and Sustainable Development (REMADS-UFF), University Federal Fluminense, Niteroi, RJ (Brazil)

2014-07-01

This work aimed to investigate the mechanisms involved in the sorption of {sup 137}Cs and {sup 60}Co as a function of the physico-chemical properties of some types of Brazilian soils and the changes on the behavior of these radionuclides due to changes in soil properties promoted by organic amendment. The experimental study was conducted in a controlled area, where pots containing different types of soils (Ferralsol, Nitisol and Histosol) and different doses of organic amendment (no amendment; 2 kg.m{sup -2} and 4 kg.m{sup -2}) were spiked with {sup 137}Cs and {sup 60}Co. The organic amendment used in this experiment was obtained in the Unit of Compost of the Organic Material of Pinheiral (RJ, Brazil), where the compost is made up from the leaves swept from the streets of the Pinheiral city. The mobility of these radionuclides in the soil was assessed through sequential chemical extraction and desorption studies as a function of pH. The bioavailability was evaluated through the effective absorption of radionuclide by root crops (Raphanus sativus, L). This study evidenced that the organic amendment plays an important role in the desorption processes of cobalt and cesium, reducing desorption of both nuclides beneath higher organic amendment dose. This behavior was observed in acid conditions as well in alkaline. However extreme acid conditions may mobilize both radionuclides, although cobalt mobility was shown to be more sensitive to low pH than cesium. (authors)

Maternal transfer of anthropogenic radionuclides to eggs in a small shark

International Nuclear Information System (INIS)

Jeffree, Ross A.; Oberhansli, Francois; Teyssie, Jean-Louis; Fowler, Scott W.

2015-01-01

Maternal transfer of radionuclides to progeny is one of the least known sources of contamination in marine biota and more information is needed to assess its radiological significance. A radiotracer study on spotted dogfish, Scyliorhinus canicula, evaluated the hypothesis that four anthropogenic radionuclides (Cobalt-60, Zinc-65, Americium-241 and Cesium-134) could be maternally transferred to eggs and each of their major components during maternal ingestion of radiolabelled food. The linear regressions between cumulative radioactivity that had been maternally ingested and the level in subsequently laid eggs were used to derive maternal-to-egg transfer factors (mTFs). These maternal transfers varied over an order of magnitude and were ranked 134 Cs >  65 Zn >  60 Co >  241 Am. This ranking was the same as their relative assimilation efficiencies in radiolabelled food consumed by adults. Among these four radionuclides the potential radiological exposure of embryos is accentuated for 65 Zn and 134 Cs due to their predominant transfer to egg yolk where they are available for subsequent absorption by the embryo as it develops prior to hatching from the egg capsule. Thus, for cartilaginous fish like shark, the potential radioecological consequences of a pulsed release of these radionuclides into the marine environment may extend beyond the temporal duration of the release. - Highlights: • Dogfish maternally transfer anthropogenic radionuclides to eggs. • Transfers are ranked 134 Cs >  65 Zn >  60 Co >  241 Am. • Both 65 Zn and 60 Co are mainly deposited in yolk

Production and dosimetric aspects of the potent Auger emitter 58mCo for targeted radionuclide therapy of small tumors

International Nuclear Information System (INIS)

Thisgaard, H.; Elema, D.R.; Jensen, M.

2011-01-01

Purpose: Based on theoretical calculations, the Auger emitter 58m Co has been identified as a potent nuclide for targeted radionuclide therapy of small tumors. During the production of this isotope, the coproduction of the long-lived ground state 58g Co is unfortunately unavoidable, as is ingrowth of the ground state following the isomeric decay of 58m Co. The impact of 58g Co as a β + - and γ-emitting impurity should be included in the dosimetric analysis. The purpose of this study was to investigate this critical part of dosimetry based on experimentally determined production yields of 58m Co and 58g Co using a low-energy cyclotron. Also, the cellular S-values for 58m Co have been calculated and are presented here for the first time. Methods: 58m Co was produced via the 58 Fe(p,n) 58m Co nuclear reaction on highly enriched 58 Fe metal. In addition, radiochemical separations of produced radio-cobalt from nat Fe target material were performed. The theoretical subcellular dosimetry calculations for 58m Co and 58g Co were performed using the MIRD formalism, and the impact of the increasing ground state impurity on the tumor-to-normal-tissue dose ratios (TND) per disintegration as a function of time after end of bombardment (EOB) was calculated. Results: 192 ± 8 MBq of 58m Co was produced in the irradiation corresponding to a production yield of 10.7 MBq/μAh. The activity of 58g Co was measured to be 0.85% ± 0.04% of the produced 58m Co activity at EOB. The radio-cobalt yields in the rapid separations were measured to be >97% with no detectable iron contaminations in the cobalt fractions. Due to the unavoidable coproduction and ingrowth of the long-lived ground state 58g Co, the TND and the potency of the 58m Co decrease with time after EOB. If a future treatment with a 58m Co labeled compound is not initiated before, e.g., 21 h after EOB, the resulting TND will be approximately 50% of the TND of 'pure' 58m Co as a result of the increased normal tissue dose from

Studies of. gamma. -ray irradiation effects on tris(. beta. -diketonato)iron(III) and cobalt(III) coordination compounds by means of Moessbauer spectroscopy and magnetic susceptibility measurements

Energy Technology Data Exchange (ETDEWEB)

Sakai, Y.; Endo, K.; Sano, H. (Tokyo Metropolitan Univ. (Japan). Faculty of Science)

1981-06-01

Both absorption Moessbauer spectroscopy and magnetic susceptibility measurements on tris(..beta..-diketonato)iron(III) and cobalt(III) compounds indicate that ligands which have phenyl group as a substituent are more stable to ..gamma..-ray radiolysis, in accordance with previous results of emission Moessbauer spectroscopic studies of /sup 57/Co-labelled tris (..beta..-diketonato)cobalt(III) compounds.

Automated multi-radionuclide separation and analysis with combined detection capability

Science.gov (United States)

Plionis, Alexander Asterios

The radiological dispersal device (RDD) is a weapon of great concern to those agencies responsible for protecting the public from the modern age of terrorism. In order to effectively respond to an RDD event, these agencies need to possess the capability to rapidly identify the radiological agents involved in the incident and assess the uptake of each individual victim. Since medical treatment for internal radiation poisoning is radionuclide-specific, it is critical to identify and quantify the radiological uptake of each individual victim. This dissertation describes the development of automated analytical components that could be used to determine and quantify multiple radionuclides in human urine bioassays. This is accomplished through the use of extraction chromatography that is plumbed in-line with one of a variety of detection instruments. Flow scintillation analysis is used for 90Sr and 210Po determination, flow gamma analysis is used assess 60 Co and 137Cs, and inductively coupled plasma mass spectrometry is used to determine actinides. Detection limits for these analytes were determined for the appropriate technique and related to their implications for health physics.

Concentration and Separation of Scandium from Ni Laterite Ore Processing Streams

Directory of Open Access Journals (Sweden)

Şerif Kaya

2017-12-01

Full Text Available The presence of a considerable amount of scandium in lateritic nickel-cobalt ores necessitates the investigation of possible processing alternatives to recover scandium as a byproduct during nickel and cobalt production. Therefore, in this study, rather than interfering with the main nickel-cobalt production circuit, the precipitation-separation behavior of scandium during a pH-controlled precipitation process from a synthetically prepared solution was investigated to adopt the Sc recovery circuit into an already existing hydrometallurgical nickel-cobalt hydroxide processing plant. The composition of the synthetic solution was determined according to the hydrometallurgical nickel laterite ore processing streams obtained from a HPAL (high-pressure sulphuric acid leaching process. In order to selectively precipitate and concentrate scandium with minimum nickel and cobalt co-precipitation, the pH of the solution was adjusted by CaCO3, MgO, Na2CO3, and NaOH. It was found that precipitation with MgO or Na2CO3 is more advantageous to obtain a precipitate containing higher amounts of scandium with minimum mass when compared to the CaCO3 route, which makes further processing more viable. As a result of this study, it is proposed that by a simple pH-controlled precipitation process, scandium can be separated from the nickel and cobalt containing process solutions as a byproduct without affecting the conventional nickel-cobalt hydroxide production. By further processing this scandium-enriched residue by means of leaching, SX (solvent extraction, and precipitation, an intermediate (NH42NaScF6 product can be obtained.

Radionuclide Sensors for Water Monitoring

International Nuclear Information System (INIS)

Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

2004-01-01

Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem that requires monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to an analytical laboratory, where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90Sr, 99Tc, and various actinides of interest. The objective of this project is to investigate novel sensor concepts and materials for sensitive and selective determination of beta- and alpha-emitting radionuclide contaminants in water. To meet the requirements for loW--level, isotope-specific detection, the proposed sensors are based on radiometric detection. As a means to address the fundamental challenge of the short ranges of beta and alpha particle s in water, our overall approach is based on localization of preconcentration/separation chemistries directly on or within the active area of a radioactivity detector. Automated microfluidics is used for sample manipulation and sensor regeneration or renewal. The outcome of these investigations will be the knowledge necessary to choose appropriate chemistries for selective preconcentration of radionuclides from environmental samples, new materials that combine chemical selectivity with scintillating properties, new materials that add chemical selectivity to solid-state diode detectors, new preconcentrating column sensors, and improved instrumentation and signal processing for selective radionuclide sensors. New knowledge will provide the basis for designing effective probes and instrumentation for field and in situ measurements

Development of a relatively cheap and simple automated separation system for a routine separation procedure based on extraction chromatography

International Nuclear Information System (INIS)

Petro Zoriy; Reinhold Flucht; Mechthild Burow; Peter Ostapczuk; Reinhard Lennartz; Myroslav Zoriy

2010-01-01

A robust analytical method has been developed in our laboratory for the separation of radionuclides by means of extraction chromatography using an automated separation system. The proposed method is both cheap and simple and provides the advantageous, rapid and accurate separation of the element of interest. The automated separation system enables a shorter separation time by maintaining a constant flow rate of solution and by avoiding clogging or bubbling in the chromatographic column. The present separation method was tested with two types of samples (water and urine) using UTEVA-, TRU- and Sr-specific resins for the separation of U, Th, Am, Pu and Sr. The total separation time for one radionuclide ranged from 60 to 100 min with the separation yield ranging from 68 to 98% depending on the elements separated. We used ICP-QMS, multi-low-level counter and alpha spectroscopy to measure the corresponding elements. (author)

The role of microorganisms in the mobility of radionuclides in soil. I. Examination of resistance to strontium, cesium, cobalt and zinc

International Nuclear Information System (INIS)

Konyi, J.; Koska, P.; Berzsenyi, G.; Gazso, L.G.; Appanna, V.D.

1997-01-01

132 microorganisms were isolated from cultivated soils sampled near a nuclear power plant. Quantitative and qualitative analysis was made concerning the macro-morphology, micro-morphology and Gram staining. Resistance of microorganisms to strontium, cesium, cobalt and zinc was determined using agar plates containing metals. Cobalt and zinc proved to be toxic at a concentration of 100 mg/l, but strontium and cesium did not inhibit the growth even at the concentration up to 200 mg/l. Results of analyses of mechanisms of zinc resistance by photometry and spectral analysis also presented. (author)

Production of radionuclides with generators

International Nuclear Information System (INIS)

Khujaev, S.; Egamediev, S.Kh.

2004-01-01

(75-85%) independently of the 99 Mo activity (250 - 1000 mCi) at the beginning and the end (up to 15 days) of the period of use. 188 W- 188 Re generator. 188 Re (T 1/2 =16.9 hours, β - m ax=2.12 MeV; γ=155 keV, 15%) is currently attractive radionuclide for radiotherapeutic applications. Rhenium-188 is produced by decay of tungsten-188 (T 1/2 =69.4 d) which can be produced by double neutron capture on enriched 188 W targets with high neutron flux. The specific activity of 188 W is reached up to 2 Ci/g. The optimal conditions for separation of 188 Re from the parent nuclide 188 W are studied. It is shown that the optimal separation condition is using acid-treated aluminium-oxide column to adsorb 188 W as isopolytungstate at pH solution of 2-4. 188 Re is eluted with 0.9% NaCl solution. The characteristics of the sodium perrhenate obtained from our generator are: radiochemical purity is 99.8%; pH 4.0-6.0; yield of 188 Re is 70-75%; breakthrough of 188 W is less than 10 -3 %. 68 Ge- 68 Ga generator. The nuclide 68 Ga (T 1/2 =68.3 min) produced by the electron capture decay of 68 Ge (T 1/2 =288 d) is useful for calibrating positron emission tomography (PET) systems. The 68 Ge is normally produced by both 66 Zn(α,2n) 68 Ge and 69 Ga(p,2n) 68 Ge nuclear reactions. The separation of daughter 68 Ga from parent 68 Ge on both aluminium oxide and tin dioxide are studied. In case of tin dioxide the optimal separation of daughter 68 Ga from parent 68 Ge can be achieved by using 1 M HCl as the eluent. It is shown that the tin dioxide - 1 M HCl generator system provides high yields of 68 Ga (75-80%) with low levels of breakthrough of 68 Ge (2 · 10 -4 %). However, the obtained final product - 68 Ga eluate in 1 M HCl can not be used for direct preparation of radiopharmaceuticals. In case of aluminium oxide we have found that preliminary annealing of aluminium oxide at 1000 deg C provides the best conditions for separation of 68 Ge- 68 Ga radionuclide chain in 0.1 M hydrochloric acid

Raman analysis of cobalt blue pigment in blue and white porcelain: A reassessment

Science.gov (United States)

Jiang, Xiaochenyang; Ma, Yanying; Chen, Yue; Li, Yuanqiu; Ma, Qinglin; Zhang, Zhaoxia; Wang, Changsui; Yang, Yimin

2018-02-01

Cobalt blue is a famous pigment in human history. In the past decade it is widely reported that the cobalt aluminate has been detected in ancient ceramics as blue colorant in glaze, yet the acquired Raman spectra are incredibly different from that of synthesised references, necessitating a reassessment of such contradictory scenario with more accurate analytic strategies. In this study, micro-Raman spectroscopy (MRS) and scanning electron microscopy (SEM) in association with energy dispersive spectrometry (EDS) were performed on under-glaze cobalt pigments from one submerged blue and white porcelain shard dated from Wanli reign (1573-1620 CE) of Ming dynasty (1365-1644 CE) excavated at Nan'ao I shipwreck off the southern coast of China. The micro-structural inspection reveals that the pigment particles have characteristics of small account, tiny size, heterogeneously distribution, and more importantly, been completely enwrapped by well-developed anorthite crystals in the glaze, indicating that the signals recorded in previous publications are probably not from cobalt pigments themselves but from outside thickset anorthite shell. The further spectromicroscopic analyses confirm this presumption when the accurate spectra of cobalt aluminate pigment and surrounding anorthite were obtained separately with precise optical positioning. Accordingly, we reassess and clarify the previous Raman studies dedicated to cobalt blue pigment in ancient ceramics, e.g. cobalt blue in celadon glaze, and in turn demonstrate the superiority and necessity of coupling spectroscopic analysis with corresponding structure observation, especially in the characterization of pigments from complicated physico-chemical environment like antiquities. Thus, this study promotes a better understanding of Raman spectroscopy study of cobalt blue pigments in art and archaeology field.

Production and dosimetric aspects of the potent Auger emitter {sup 58m}Co for targeted radionuclide therapy of small tumors

Energy Technology Data Exchange (ETDEWEB)

Thisgaard, H.; Elema, D.R.; Jensen, M. [PET and Cyclotron Unit, Nuclear Medicine Department, Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense, Denmark and Institute of Clinical Research, University of Southern Denmark, Winsloewparken 19, DK-5000 Odense (Denmark); The Hevesy Laboratory, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, DK-4000 Roskilde (Denmark)

2011-08-15

Purpose: Based on theoretical calculations, the Auger emitter {sup 58m}Co has been identified as a potent nuclide for targeted radionuclide therapy of small tumors. During the production of this isotope, the coproduction of the long-lived ground state {sup 58g}Co is unfortunately unavoidable, as is ingrowth of the ground state following the isomeric decay of {sup 58m}Co. The impact of {sup 58g}Co as a {beta}{sup +}- and {gamma}-emitting impurity should be included in the dosimetric analysis. The purpose of this study was to investigate this critical part of dosimetry based on experimentally determined production yields of {sup 58m}Co and {sup 58g}Co using a low-energy cyclotron. Also, the cellular S-values for {sup 58m}Co have been calculated and are presented here for the first time. Methods: {sup 58m}Co was produced via the {sup 58}Fe(p,n){sup 58m}Co nuclear reaction on highly enriched {sup 58}Fe metal. In addition, radiochemical separations of produced radio-cobalt from {sup nat}Fe target material were performed. The theoretical subcellular dosimetry calculations for {sup 58m}Co and {sup 58g}Co were performed using the MIRD formalism, and the impact of the increasing ground state impurity on the tumor-to-normal-tissue dose ratios (TND) per disintegration as a function of time after end of bombardment (EOB) was calculated. Results: 192 {+-} 8 MBq of {sup 58m}Co was produced in the irradiation corresponding to a production yield of 10.7 MBq/{mu}Ah. The activity of {sup 58g}Co was measured to be 0.85% {+-} 0.04% of the produced {sup 58m}Co activity at EOB. The radio-cobalt yields in the rapid separations were measured to be >97% with no detectable iron contaminations in the cobalt fractions. Due to the unavoidable coproduction and ingrowth of the long-lived ground state {sup 58g}Co, the TND and the potency of the {sup 58m}Co decrease with time after EOB. If a future treatment with a {sup 58m}Co labeled compound is not initiated before, e.g., 21 h after EOB, the

Evaluation of nuclear reaction cross sections for optimization of production of the emerging diagnostic radionuclide "5"5Co

International Nuclear Information System (INIS)

Amjed, N.; Hussain, M.; Aslam, M.N.; Tárkányi, F.; Qaim, S.M.

2016-01-01

The excitation functions of the "5"4Fe(d,n)"5"5Co, "5"6Fe(p,2n)"5"5Co and "5"8Ni(p,α)"5"5Co reactions were analyzed with relevance to the production of the β"+-emitter "5"5Co (T_½=17.53 h), a promising cobalt radionuclide for PET imaging. The nuclear model codes ALICE-IPPE, EMPIRE and TALYS were used to check the consistency of the experimental data. The statistically fitted excitation function was employed to calculate the integral yield of the product. The amounts of the radioactive impurities "5"6Co and "5"7Co were assessed. A comparison of the three investigated production routes is given. - Highlights: • Evaluation of "5"4Fe(d,n)"5"5Co, "5"6Fe(p,2n)"5"5Co and "5"8Ni(p,α)"5"5Co reactions. • Detailed nuclear model calculations (TALYS and EMPIRE) and statistical fitting of the selected data. • Estimation of integral yield and impurity level in the production of "5"5Co. • Comparison of major production routes of "5"5Co.

Spin-dependent transport in cobalt nanocontacts

Energy Technology Data Exchange (ETDEWEB)

Sarau, G.

2007-04-16

The magnetoresistance response of cobalt nanocontacts with varying geometries formed between two extended electrodes has been experimentally investigated and linked to micromagnetic simulations. The contribution of the nanoconstriction to the measured magnetoresistance signal has been separated from that of the electrode bulk. The different nanocontact geometries exhibit different shape anisotropies resulting in a characteristic behavior of the magnetization at each nanocontact. The magnetization reversal processes are explained on the basis of the anisotropic magnetoresistance and domain wall scattering effects. The domain wall resistance takes positive values, which is in agreement with models based on the spin mistracking inside the domain wall. The 4 K MR measurements are found to be influenced by the exchange bias effect between the ferromagnetic cobalt electrodes and the antiferromagnetic oxidized Co surface. When cooling down in an applied magnetic field, the uniform biased Co layer behaves as if it possesses a unidirectional anisotropy axis along the field cooling direction. In the zero field cooling case, the exchange bias varies locally throughout the sample giving rise to non-reproducible successive MR traces. (orig.)

Accumulation of radionuclides by lichen symbionts

Energy Technology Data Exchange (ETDEWEB)

Nifontova, M G; Kulikov, N V [AN SSSR, Sverdlovsk. Inst. Ehkologii Rastenij i Zhivotnykh

1983-01-01

The aim of investigation is the quantitative estimation of ability and role of separate symbionts in the accumulation of radionuclides. As investigation volumes, durably cultivated green lichen alga Trebouxia erici and lichen fungi extracted from Cladonia rangiferina, Parmelia caperata and Acarospora fuscata are used. The accumulation of radioactive isotopes with fungi and seaweeds is estimated according to accumulation coefficients (AC) which are the ratio of radiation concentration in plants and agarized medium. Radionuclide content (/sup 90/Sr and /sup 137/Cs) is determined radiometrically. A special series of experiments is done to investigate radionuclide accumulation dependences with lichen seaweed and fungi on light conditions. It is shown that both symbionts of lichen-seaweed and fungus take part in the accumulation of radionuclide from outer medium (atmospheric fall-out and soil). However fungus component constituting the base of structural organization of thallus provides the greater part of radionuclides accumulated by the plant. Along with this the violation of viability of seaweed symbionts particularly in the case of light deficiency brings about the reduction of /sup 137/Cs sorption by seaweeds and tells on the total content of radiocesium in plant thallus.

Flotation separation of uranium from contaminated soils

International Nuclear Information System (INIS)

Misra, M.; Mehta, R.; Garcia, H.; Chai, C.D.; Smith, R.W.

1995-01-01

The volume of low-level contaminated soil at the Department of Energy's Nuclear Weapon Sites are in the order of several million tons. Most of the contaminants are uranium, plutonium, other heavy metals and organic compounds. Selected physical separation processes have shown demonstrated potential in concentrating the radionuclides in a small fraction of the soil. Depending upon the size, nature of bonding and distributions of radionuclides, more than 90% of the radionuclide activity can be concentrated in a small volume of fraction of the soil. The physico-chemical separation processes such as flotation in a mechanical and microbubble tall column cell have shown promising applications in cleaning up the high volume contaminated soil

Influence of Reduction Promoters on Stability of Cobalt/g-Alumina Fischer-Tropsch Synthesis Catalysts

Directory of Open Access Journals (Sweden)

Gary Jacobs

2014-03-01

Full Text Available This focused review article underscores how metal reduction promoters can impact deactivation phenomena associated with cobalt Fischer-Tropsch synthesis catalysts. Promoters can exacerbate sintering if the additional cobalt metal clusters, formed as a result of the promoting effect, are in close proximity at the nanoscale to other cobalt particles on the surface. Recent efforts have shown that when promoters are used to facilitate the reduction of small crystallites with the aim of increasing surface Co0 site densities (e.g., in research catalysts, ultra-small crystallites (e.g., <2–4.4 nm formed are more susceptible to oxidation at high conversion relative to larger ones. The choice of promoter is important, as certain metals (e.g., Au that promote cobalt oxide reduction can separate from cobalt during oxidation-reduction (regeneration cycles. Finally, some elements have been identified to promote reduction but either poison the surface of Co0 (e.g., Cu, or produce excessive light gas selectivity (e.g., Cu and Pd, or Au at high loading. Computational studies indicate that certain promoters may inhibit polymeric C formation by hindering C-C coupling.

Radionuclide inventory and source terms for the surplus production reactors at Hanford

International Nuclear Information System (INIS)

Miller, R.L.; Steffes, J.M.

1987-01-01

Radionuclide inventories have been estimated for the eight surplus production reactors at Hanford. The inventories listed represent more than 95% of the total curie burden; the remaining 5% is distributed in piping, tunnels, and various other locations within the reactor building and unaccounted for inventories within the reactors or fuel storage basins. Estimates are conservative as the methodology was designed to overestimate the radionuclide inventories in the facilities. The estimated inventory per reactor facility ranges from 13,000 curies to 58,000 curies. The majority of the present inventory consists of tritium, carbon-14, cobalt-60, and nickel-63. The information in this document combines data from past characterization efforts and introduces adjustments for added information and refinement. The inventory of hazardous materials in the reactor facilities is also addressed. This document has been revised to include new reduced inventory figures for chlorine-36. The new figures were derived from recent analysis of irradiated graphite from the 105-kW reactor

A vector Wiener filter for dual-radionuclide imaging

International Nuclear Information System (INIS)

Links, J.M.; Prince, J.L.; Gupta, S.N.

1996-01-01

The routine use of a single radionuclide for patient imaging in nuclear medicine can be complemented by studies employing two tracers to examine two different processes in a single organ, most frequently by simultaneous imaging of both radionuclides in two different energy windows. In addition, simultaneous transmission/emission imaging with dual-radionuclides has been described, with one radionuclide used for the transmission study and a second for the emission study. There is thus currently considerable interest in dual-radionuclide imaging. A major problem with all dual-radionuclide imaging is the crosstalk between the two radionuclides. Such crosstalk frequently occurs, because scattered radiation from the higher energy radionuclide is detected in the lower energy window, and because the lower energy radionuclide may have higher energy emissions which are detected in the higher energy window. The authors have previously described the use of Fourier-based restoration filtering in single photon emission computed tomography (SPECT) and positron emission tomography (PET) to improve quantitative accuracy by designing a Wiener or other Fourier filter to partially restore the loss of contrast due to scatter and finite spatial resolution effects. The authors describe here the derivation and initial validation of an extension of such filtering for dual-radionuclide imaging that simultaneously (1) improves contrast in each radionuclide's direct image, (2) reduces image noise, and (3) reduces the crosstalk contribution from the other radionuclide. This filter is based on a vector version of the Wiener filter, which is shown to be superior [in the minimum mean square error (MMSE) sense] to the sequential application of separate crosstalk and restoration filters

Characteristics of radionuclide accumulation in benthic organisms and fish of the Barents and Kara Seas

International Nuclear Information System (INIS)

Matishov, G.G.; Matishov, D.G.; Rissanen, C.

1995-01-01

Artificial radionuclides play a specific role in the hydrochemical, geochemical, and hydrobiological processes that are currently occurring in the western Arctic. The existing data on radioactive contamination of different plant and animal species inhabiting the sea shelf are fragmentary. Hence, it was difficult to follow the transformation of radionuclides during their transmission along food chains, from phyto- and zoo-plankton to benthos, fish, birds, and marine mammals. In 1990-1994, the Murmansk Institute of Marine Biology organized expeditions to collect samples of residues on the sea floor and also of benthos, benthic fish, macrophytes, and other organisms inhabiting the shelf of the Barents and Kara Seas. These samples were tested for cesium-137, cesium-134, strontium-90, plutonium-239, plutonium-240, americium-241, and cobalt-60 in Rovaniemi (Finland) by the regional radiation administration of the Finnish Centre for Radiation and Nuclear Safety. Over 1000 tests were made. Their results provided new data on the content and distribution of these radionuclides among different components of marine ecosystems. 7 refs

Cobalt metabolism and toxicology—A brief update

International Nuclear Information System (INIS)

Simonsen, Lars Ole; Harbak, Henrik; Bennekou, Poul

2012-01-01

Cobalt metabolism and toxicology are summarized. The biological functions of cobalt are updated in the light of recent understanding of cobalt interference with the sensing in almost all animal cells of oxygen deficiency (hypoxia). Cobalt (Co 2+ ) stabilizes the transcriptional activator hypoxia-inducible factor (HIF) and thus mimics hypoxia and stimulates erythropoietin (Epo) production, but probably also by the same mechanism induces a coordinated up-regulation of a number of adaptive responses to hypoxia, many with potential carcinogenic effects. This means on the other hand that cobalt (Co 2+ ) also may have beneficial effects under conditions of tissue hypoxia, and possibly can represent an alternative to hypoxic preconditioning. Cobalt is acutely toxic in larger doses, and in mammalian in vitro test systems cobalt ions and cobalt metal are cytotoxic and induce apoptosis and at higher concentrations necrosis with inflammatory response. Cobalt metal and salts are also genotoxic, mainly caused by oxidative DNA damage by reactive oxygen species, perhaps combined with inhibition of DNA repair. Of note, the evidence for carcinogenicity of cobalt metal and cobalt sulfate is considered sufficient in experimental animals, but is as yet considered inadequate in humans. Interestingly, some of the toxic effects of cobalt (Co 2+ ) have recently been proposed to be due to putative inhibition of Ca 2+ entry and Ca 2+ -signaling and competition with Ca 2+ for intracellular Ca 2+ -binding proteins. The tissue partitioning of cobalt (Co 2+ ) and its time-dependence after administration of a single dose have been studied in man, but mainly in laboratory animals. Cobalt is accumulated primarily in liver, kidney, pancreas, and heart, with the relative content in skeleton and skeletal muscle increasing with time after cobalt administration. In man the renal excretion is initially rapid but decreasing over the first days, followed by a second, slow phase lasting several weeks, and

Initial Radionuclide Inventories

Energy Technology Data Exchange (ETDEWEB)

H. Miller

2004-09-19

The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only. Bounding waste stream information and data were collected that capture probable limits. For commercially generated waste, this analysis considers alternative waste stream projections to bound the characteristics of wastes likely to be encountered using arrival scenarios that potentially impact the commercial spent nuclear fuel (CSNF) waste stream. For TSPA-LA, this radionuclide inventory analysis considers U.S. Department of Energy (DOE) high-level radioactive waste (DHLW) glass and two types of spent nuclear fuel (SNF): CSNF and DOE-owned (DSNF). These wastes are placed in two groups of waste packages: the CSNF waste package and the codisposal waste package (CDSP), which are designated to contain DHLW glass and DSNF, or DHLW glass only. The radionuclide inventory for naval SNF is provided separately in the classified ''Naval Nuclear Propulsion Program Technical Support Document'' for the License Application. As noted previously, the radionuclide inventory data presented here is intended only for TSPA-LA postclosure calculations. It is not applicable to preclosure safety calculations. Safe storage, transportation, and ultimate disposal of these wastes require safety analyses to support the design and licensing of repository equipment and facilities. These analyses will require radionuclide inventories to represent the radioactive source term that must be accommodated during handling, storage and disposition of these wastes. This analysis uses the best available information to identify the radionuclide inventory that is expected at the last year of last emplacement

High temperature H2/CO2 separation using cobalt oxide silica membranes

Energy Technology Data Exchange (ETDEWEB)

Smart, S.; Diniz da Costa, J.C. [The University of Queensland, FIMLab - Films and Inorganic Membrane Laboratory, School of Chemical Engineering, Brisbane, Qld 4072 (Australia); Vente, J.F. [Energy research Centre of the Netherlands ECN, P.O. Box 1, 1755 ZG Petten (Netherlands)

2012-09-15

In this work high quality cobalt oxide silica membranes were synthesized on alumina supports using a sol-gel, dip coating method. The membranes were subsequently connected into a steel module using a graphite based proprietary sealing method. The sealed membranes were tested for single gas permeance of He, H2, N2 and CO2 at temperatures up to 600C and feed pressures up to 600 kPa. Pressure tests confirmed that the sealing system was effective as no gas leaks were observed during testing. A H2 permeance of 1.9 x 10{sup -7} mol m{sup -2} s{sup -1} Pa-1 was measured in conjunction with a H2/CO2 permselectivity of more than 1500, suggesting that the membranes had a very narrow pore size distribution and an average pore diameter of approximately 3 Angstrom. The high temperature testing demonstrated that the incorporation of cobalt oxide into the silica matrix produced a structure with a higher thermal stability, able to resist thermally induced densification up to at least 600C. Furthermore, the membranes were tested for H2/CO2 binary feed mixtures between 400 and 600C. At these conditions, the reverse of the water gas shift reaction occurred, inadvertently generating CO and water which increased as a function of CO2 feed concentration. The purity of H2 in the permeate stream significantly decreased for CO2 feed concentrations in excess of 50 vol%. However, the gas mixtures (H2, CO2, CO and water) had a more profound effect on the H2 permeate flow rates which significantly decreased, almost exponentially as the CO2 feed concentration increased.

Chemistry and analysis of radionuclides

CERN Document Server

Lehto, Jukka

2010-01-01

Written by chemists for chemists, this is a comprehensive guide to the important radionuclides as well as techniques for their separation and analysis. It introduces readers to the important laboratory techniques and methodologies in the field, providing practical instructions on how to handle nuclear waste and radioactivity in the environment.

Cobalt metabolism and toxicology-A brief update

Energy Technology Data Exchange (ETDEWEB)

Simonsen, Lars Ole, E-mail: LOSimonsen@dadlnet.dk; Harbak, Henrik; Bennekou, Poul

2012-08-15

Cobalt metabolism and toxicology are summarized. The biological functions of cobalt are updated in the light of recent understanding of cobalt interference with the sensing in almost all animal cells of oxygen deficiency (hypoxia). Cobalt (Co{sup 2+}) stabilizes the transcriptional activator hypoxia-inducible factor (HIF) and thus mimics hypoxia and stimulates erythropoietin (Epo) production, but probably also by the same mechanism induces a coordinated up-regulation of a number of adaptive responses to hypoxia, many with potential carcinogenic effects. This means on the other hand that cobalt (Co{sup 2+}) also may have beneficial effects under conditions of tissue hypoxia, and possibly can represent an alternative to hypoxic preconditioning. Cobalt is acutely toxic in larger doses, and in mammalian in vitro test systems cobalt ions and cobalt metal are cytotoxic and induce apoptosis and at higher concentrations necrosis with inflammatory response. Cobalt metal and salts are also genotoxic, mainly caused by oxidative DNA damage by reactive oxygen species, perhaps combined with inhibition of DNA repair. Of note, the evidence for carcinogenicity of cobalt metal and cobalt sulfate is considered sufficient in experimental animals, but is as yet considered inadequate in humans. Interestingly, some of the toxic effects of cobalt (Co{sup 2+}) have recently been proposed to be due to putative inhibition of Ca{sup 2+} entry and Ca{sup 2+}-signaling and competition with Ca{sup 2+} for intracellular Ca{sup 2+}-binding proteins. The tissue partitioning of cobalt (Co{sup 2+}) and its time-dependence after administration of a single dose have been studied in man, but mainly in laboratory animals. Cobalt is accumulated primarily in liver, kidney, pancreas, and heart, with the relative content in skeleton and skeletal muscle increasing with time after cobalt administration. In man the renal excretion is initially rapid but decreasing over the first days, followed by a second, slow

Cobalt Fischer-Tropsch catalysts: influence of cobalt dispersion and titanium oxides promotion

Energy Technology Data Exchange (ETDEWEB)

Azib, H

1996-04-10

The aim of this work is to study the effect of Sol-Gel preparation parameters which occur in silica supported cobalt catalysts synthesis. These catalysts are particularly used for the waxes production in natural gas processing. The solids have been characterized by several techniques: transmission electron microscopy (TEM), X-ray absorption near edge spectroscopy (XANES), programmed temperature reduction (TPR), infrared spectroscopy (IR), ultraviolet spectroscopy (UV), Magnetism, thermodesorption of H{sub 2} (TPD). The results indicate that the control of the cobalt dispersion and oxide phases nature is possible by modifying Sol-Gel parameters. The catalytic tests in Fischer-Tropsch synthesis were conducted on a pilot unit under pressure (20 atm) and suggested that turnover rates were independent of Co crystallite size, Co phases in the solids (Co deg., cobalt silicate) and titanium oxide promotion. On the other methane, the C{sub 3}{sup +} hydrocarbon selectivity is increased with increasing crystallite size. Inversely, the methane production is favoured by very small crystallites, cobalt silicate increase and titanium addition. However, the latter, used as a cobalt promoter, has a benefic effect on the active phase stability during the synthesis. (author). 149 refs., 102 figs., 71 tabs.

Evaluation of obstructive uropathy in children: radionuclide renography vs. the Whitaker test

International Nuclear Information System (INIS)

Senac, M.O. Jr.; Miller, J.H.; Stanley, P.

1984-01-01

Differentiation of obstructed from dilated, nonobstructed urinary systems in the postoperative child is a difficult diagnostic problem. A comparison study was performed in 21 children with hydroureteronephrosis using the Whitaker test in combination with conventional radionuclide renography and/or diuretic (furosemide)-augmented radionuclide renography. The results of each method were corelated with the clinical assessment and surgical findings. Conventional renography was found to be an unreliable study, with a clinical correctness of only 57%. Results were more favorable for both the Whitaker test and diurectic-augmented radionuclide renography, with clinical correctness in 86% and 85%, respectively. Due to the noninvasive nature of the study, diuretic-augmented radionuclide renography should be the initial procedure once hydroureteronephrosis is established. A recommended algorithm of the child with postoperative hydroureteronephrosis is suggested

Method for the simultaneous recovery of radionuclides from liquid radioactive wastes using a solvent

Science.gov (United States)

Romanovskiy, Valeriy Nicholiavich; Smirnov, Igor V.; Babain, Vasiliy A.; Todd, Terry A.; Brewer, Ken N.

2001-01-01

The present invention relates to solvents, and methods, for selectively extracting and recovering radionuclides, especially cesium and strontium, rare earths and actinides from liquid radioactive wastes. More specifically, the invention relates to extracting agent solvent compositions comprising complex organoboron compounds, substituted polyethylene glycols, and neutral organophosphorus compounds in a diluent. The preferred solvent comprises a chlorinated cobalt dicarbollide, diphenyl-dibutylmethylenecarbamoylphosphine oxide, PEG-400, and a diluent of phenylpolyfluoroalkyl sulfone. The invention also provides a method of using the invention extracting agents to recover cesium, strontium, rare earths and actinides from liquid radioactive waste.

Cobalt-60 production in CANDU power reactors

International Nuclear Information System (INIS)

Slack, J.; Norton, J.L.; Malkoske, G.R.

2003-01-01

MDS Nordion has been supplying cobalt-60 sources to industry for industrial and medical purposes since 1946. These cobalt-60 sources are used in many market and product segments. The major application is in the health care industry where irradiators are used to sterilize single use medical products. These irradiators are designed and built by MDS Nordion and are used by manufacturers of surgical kits, gloves, gowns, drapes and other medical products. The irradiator is a large shielded room with a storage pool for the cobalt-60 sources. The medical products are circulated through the shielded room and exposed to the cobalt-60 sources. This treatment sterilizes the medical products which can then be shipped to hospitals for immediate use. Other applications for this irradiation technology include sanitisation of cosmetics, microbial reduction of pharmaceutical raw materials and food irradiation. The cobalt-60 sources are manufactured by MDS Nordion in their Cobalt Operations Facility in Kanata. More than 75,000 cobalt-60 sources for use in irradiators have been manufactured by MDS Nordion. The cobalt-60 sources are double encapsulated in stainless steel capsules, seal welded and helium leak tested. Each source may contain up to 14,000 curies. These sources are shipped to over 170 industrial irradiators around the world. This paper will focus on the MDS Nordion proprietary technology used to produce the cobalt-60 isotope in CANDU reactors. Almost 55 years ago MDS Nordion and Atomic Energy of Canada developed the process for manufacturing cobalt-60 at the Chalk River Labs, in Ontario, Canada. A cobalt-59 target was introduced into a research reactor where the cobalt-59 atom absorbed one neutron to become cobalt-60. Once the cobalt-60 material was removed from the research reactor it was encapsulated in stainless steel and seal welded using a Tungsten Inert Gas weld. The first cobalt-60 sources manufactured using material from the Chalk River Labs were used in cancer

Catalytic Activity of Cobalt Grafted on Ordered Mesoporous Silica Materials in N2O Decomposition and CO Oxidation.

Czech Academy of Sciences Publication Activity Database

Kuboňová, L.; Peikertová, P.; Mamulová Kutláková, K.; Jirátová, Květa; Słowik, G.; Obalová, L.; Cool, P.

2017-01-01

Roč. 437, AUG 2017 (2017), s. 57-72 ISSN 2468-8231 R&D Projects: GA ČR GA14-13750S Institutional support: RVO:67985858 Keywords : mesoporous ordered silica * cobalt * N2O decomposition Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering

Electroplated zinc-cobalt alloy

International Nuclear Information System (INIS)

Carpenter, D.E.O.S.; Farr, J.P.G.

2005-01-01

Recent work on the deposition and use of ectrodeposited zinc-cobalt alloys is surveyed. Alloys containing lower of Nuclear quantities of cobalt are potentially more useful. The structures of the deposits is related to their chemical and mechanical properties. The inclusion of oxide and its role in the deposition mechanism may be significant. Chemical and engineering properties relate to the metallurgical structure of the alloys, which derives from the mechanism of deposition. The inclusion of oxides and hydroxides in the electroplate may provide evidence for this mechanism. Electrochemical impedance measurements have been made at significant deposition potentials, in alkaline electrolytes. These reveal a complex electrode behaviour which depends not only on the electrode potential but on the Co content of the electrolyte. For the relevant range of cathodic potential zinc-cobalt alloy electrodeposition occurs through a stratified interface. The formation of an absorbed layer ZnOH/sup +/ is the initial step, this inhibits the deposition of cobalt at low cathodic potentials, so explaining its 'anomalous deposition'. A porous layer of zinc forms on the adsorbed ZnOH/sup +/ at underpotential. As the potential becomes more cathodic, cobalt co- deposits from its electrolytic complex forming a metallic solid solution of Co in Zn. In electrolytes containing a high concentration of cobalt a mixed entity (ZnCo)/sub +/ is assumed to adsorb at the cathode from which a CoZn intermetallic deposits. (author)

Radionuclide transport in a single fissure

International Nuclear Information System (INIS)

Eriksen, T.E.

1988-12-01

The study of radionuclide migration through rock is currently of great interest due to its relevance to the possible escape paths into the biosphere of radionuclides released from high level radioactive wastes burried in deep geological repositories. While water will provide the vehicle for transportation, interaction with geological material may greatly influence the radionuclide movement relative that of water. A flow system for laboratory studies of radionuclide transport in natural fissures in granitic rock under reducing conditions is described. The system based on the use of synthetic ground water equilibrated with granitic rock in a well sealed system, allow experiments to be carried out at -240 mV reduction potential. In flow experiments with technetium the retardation was found to be dependent on the method used for reducing TcO 4 - . The preparation of the tracer solutions is crucial, as some of the redox-reactions may be very slow. The dynamics of the Tc(VII) reduction and also speciation need to be carried out in separate experiments. (4 illustrations, 5 tables)

Cobalt allergy in hard metal workers

Energy Technology Data Exchange (ETDEWEB)

Fischer, T; Rystedt, I

1983-03-01

Hard metal contains about 10% cobalt. 853 hard metal workers were examined and patch tested with substances from their environment. Initial patch tests with 1% cobalt chloride showed 62 positive reactions. By means of secondary serial dilution tests, allergic reactions to cobalt were reproduced in 9 men and 30 women. Weak reactions could not normally be reproduced. A history of hand eczema was found in 36 of the 39 individuals with reproducible positive test reactions to cobalt, while 21 of 23 with a positive initial patch test but negative serial dilution test had never had any skin problems. Hand etching and hand grinding, mainly female activities and traumatic to the hands, were found to involve the greatest risk of cobalt sensitization. 24 individuals had an isolated cobalt allergy. They had probably been sensitized by hard metal work, while the individuals, all women, who had simultaneous nickel allergy had probably been sensitized to nickel before their employment and then became sensitized to cobalt by hard metal work. A traumatic occupation, which causes irritant contact dermatitis and/or a previous contact allergy or atopy is probably a prerequisite for the development of cobalt allergy.

Separation of ionic solutes

International Nuclear Information System (INIS)

1986-01-01

The conference proceedings contain 44 papers of which 19 were incorporated in INIS. The subject of these is the use of solvent extraction or emulsion membrane extraction for separation of fission products, rare earth compounds and actinide compunds; the sorption of radionuclides; and the use of adsorbents and chelating agents in separation processes. (J.P.)

Pharmacokinetics of inorganic cobalt and a vitamin B12 supplement in the Thoroughbred horse: Differentiating cobalt abuse from supplementation.

Science.gov (United States)

Hillyer, L L; Ridd, Z; Fenwick, S; Hincks, P; Paine, S W

2018-05-01

While cobalt is an essential micronutrient for vitamin B 12 synthesis in the horse, at supraphysiological concentrations, it has been shown to enhance performance in human subjects and rats, and there is evidence that its administration in high doses to horses poses a welfare threat. Animal sport regulators currently control cobalt abuse via international race day thresholds, but this work was initiated to explore means of potentially adding to application of those thresholds since cobalt may be present in physiological concentrations. To devise a scientific basis for differentiation between presence of cobalt from bona fide supplementation and cobalt doping through the use of ratios. Six Thoroughbred horses were given 10 mL vitamin B 12 /cobalt supplement (Hemo-15 ® ; Vetoquinol, Buckingham, Buckinghamshire, UK., 1.5 mg B 12 , 7 mg cobalt gluconate = 983 μg total Co) as an i.v. bolus then an i.v. infusion (15 min) of 100 mg cobalt chloride (45.39 mg Co) 6 weeks later. Pre-and post-administration plasma and urine samples were analysed for cobalt and vitamin B 12 . Urine and plasma samples were analysed for vitamin B 12 using an immunoassay and cobalt concentrations were measured via ICP-MS. Baseline concentrations of cobalt in urine and plasma for each horse were subtracted from their cobalt concentrations post-administration for the PK analysis. Compartmental analysis was used for the determination of plasma PK parameters for cobalt using commercially available software. On administration of a vitamin B 12 /cobalt supplement, the ratio of cobalt to vitamin B 12 in plasma rapidly increased to approximately 3 and then rapidly declined below a ratio of 1 and then back to near baseline over the next week. On administration of 100 mg cobalt chloride, the ratio initially exceeded 10 in plasma and then declined with the lower 95% confidence interval remaining above a ratio of 1 for 7 days. For two horses with extended sampling, the plasma ratio remained above one for

COBALT SALTS PRODUCTION BY USING SOLVENT EXTRACTION

Directory of Open Access Journals (Sweden)

Liudmila V. Dyakova

2010-06-01

Full Text Available The paper deals with the extracting cobalt salts by using mixtures on the basis of tertiary amine from multicomponent solutions from the process of hydrochloride leaching of cobalt concentrate. The optimal composition for the extraction mixture, the relationship between the cobalt distribution coefficients and modifier’s nature and concentration, and the saltingout agent type have been determined. A hydrochloride extraction technology of cobalt concentrate yielding a purified concentrated cobalt solution for the production of pure cobalt salts has been developed and introduced at Severonikel combine.

Calcium-assisted reduction of cobalt ferrite nanoparticles for nanostructured iron cobalt with enhanced magnetic performance

International Nuclear Information System (INIS)

Qi, B.; Andrew, J. S.; Arnold, D. P.

2017-01-01

This paper demonstrates the potential of a calcium-assisted reduction process for synthesizing fine-grain (~100 nm) metal alloys from metal oxide nanoparticles. To demonstrate the process, an iron cobalt alloy (Fe_6_6Co_3_4) is obtained by hydrogen annealing 7-nm cobalt ferrite (CoFe_2O_4) nanoparticles in the presence of calcium granules. The calcium serves as a strong reducing agent, promoting the phase transition from cobalt ferrite to a metallic iron cobalt alloy, while maintaining high crystallinity. Magnetic measurements demonstrate the annealing temperature is the dominant factor of tuning the grain size and magnetic properties. Annealing at 700 °C for 1 h maximizes the magnetic saturation, up to 2.4 T (235 emu/g), which matches that of bulk iron cobalt.

Calcium-assisted reduction of cobalt ferrite nanoparticles for nanostructured iron cobalt with enhanced magnetic performance

Energy Technology Data Exchange (ETDEWEB)

Qi, B. [University of Florida, Interdisciplinary Microsystems Group, Department of Electrical and Computer Engineering (United States); Andrew, J. S. [University of Florida, Department of Materials Science and Engineering (United States); Arnold, D. P., E-mail: darnold@ufl.edu [University of Florida, Interdisciplinary Microsystems Group, Department of Electrical and Computer Engineering (United States)

2017-03-15

This paper demonstrates the potential of a calcium-assisted reduction process for synthesizing fine-grain (~100 nm) metal alloys from metal oxide nanoparticles. To demonstrate the process, an iron cobalt alloy (Fe{sub 66}Co{sub 34}) is obtained by hydrogen annealing 7-nm cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles in the presence of calcium granules. The calcium serves as a strong reducing agent, promoting the phase transition from cobalt ferrite to a metallic iron cobalt alloy, while maintaining high crystallinity. Magnetic measurements demonstrate the annealing temperature is the dominant factor of tuning the grain size and magnetic properties. Annealing at 700 °C for 1 h maximizes the magnetic saturation, up to 2.4 T (235 emu/g), which matches that of bulk iron cobalt.

Uptake of γ-emitting radionuclides by aquatic biota exposed to contaminated water before and after passage through the ground

International Nuclear Information System (INIS)

Cushing, C.E.; Rickard, W.H.; Watson, D.G.

1984-01-01

Three experimental systems were designed to investigate the differential accumulation of radionuclides by biota from low-level aqueous effluents after passage through the ground. One system received river water (control), one received dilute low-level radioactive effluents (trench), and the third received the low-level effluents after it had percolated through about 260 m or porous gravel (springs). Biota studied included filamentous green algae, clams (Corbicula), goldfish (Carassius auratus), carp (Cyprinus carpio), and Veronica. Trophic level differences in accumulation of the various radionuclides from the diluted trench water were not consistent but generally followed the pattern algae > goldfish > molluscs > carp. Cobalt-60 was accumulated to the highest level of any radionuclide, and accumulation levels at the three sites were directly related to the concentration of 60 Co in the water. Manganese-54, 59 Fe, and 106 Ru were also accumulated to measurable levels in biota at the springs site indicating their bioavailability after passage through the ground

Nickel acts as an adjuvant during cobalt sensitization

DEFF Research Database (Denmark)

Bonefeld, Charlotte Menne; Nielsen, Morten Milek; Vennegaard, Marie T.

2015-01-01

Metal allergy is the most frequent form of contact allergy with nickel and cobalt being the main culprits. Typically, exposure comes from metal-alloys where nickel and cobalt co-exist. Importantly, very little is known about how co-exposure to nickel and cobalt affects the immune system. We...... investigated these effects by using a recently developed mouse model. Mice were epicutaneously sensitized with i) nickel alone, ii) nickel in the presence of cobalt, iii) cobalt alone, or iv) cobalt in the presence of nickel, and then followed by challenge with either nickel or cobalt alone. We found...... that sensitization with nickel alone induced more local inflammation than cobalt alone as measured by increased ear-swelling. Furthermore, the presence of nickel during sensitization to cobalt led to a stronger challenge response to cobalt as seen by increased ear-swelling and increased B and T cell responses...

Study the effect of calcination temperature on physical and magnetic properties of bare Cobalt nanoparticles and that coated with silica shell

International Nuclear Information System (INIS)

Arabi, H.; Pourarian, F.; Chahkandinejad, R.

2012-01-01

In this paper, in order to investigate the effect of calcination temperature on the structural and magnetic properties of cobalt nanoparticles, samples have been prepared by Co-precipitation method at different calcination temperature. Cobalt nanoparticles have been prepared by Co-precipitation method at room temperature using hydrazine as reducing in ethanol hydrazine alkaline environment. This agent reduces cobalt salts to Cobalt nanoparticles in FCC and HCP phases. Phase analysis and investigation of Structural properties of the samples using X-ray diffraction patterns (XRD) confirm the formation of hexagonal phases of Co nanoparticles. Transmission electron microscopy was used for determining the size and shape morphology of nanoparticles. Magnetic properties of these nanoparticles have been investigated using a Vibrating sample magnetometer. The results indicate that these nanoparticles are ferromagnetic at room temperature. In addition, in this paper Co nanoparticles coated with silica shell have been prepared by the wet chemical method. Transmission electron microscopy images showed the cobalt core with average diameter of 17-20 nm coated by a silica shell with thickness of 5-7 nm. Hysteresis Loop of these Co nanoparticles coated by silica shell illustrates 16.9 emu/gr for saturation magnetization at 10000 (Oe), which is much less than that of Cobalt nanoparticles

Removal of cobalt from lubricant oil by the use of bentonite: equilibrium, kinetic and adsorption preliminary studies

Energy Technology Data Exchange (ETDEWEB)

Cuccia, Valeria; Seles, Sandro R.N.; Ladeira, Ana Cláudia Queiroz, E-mail: vc@cdtn.br, E-mail: seless@cdtn.br, E-mail: acql@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-11-01

Radionuclides may contaminate lubricant oils in nuclear power plants. In Brazil, this kind of waste has been stored in the generator's facilities, awaiting treatment alternatives. This work intends to investigate a process to treat it for final deposition, using bentonite as sorbent material. This process will result in decontaminated oil, free from radiological control, and radioactive loaded sorbent, with considerable volume reduction of the radioactive waste. The study focuses in cobalt removal from a simulated oil waste (non-active). The production of the simulated waste is described. Bentonite was used for equilibrium time determination, kinetic and adsorption studies. Cobalt adsorption equilibrium was rapidly attained after 30 minutes. The data was used for modelling the system's kinetic, applying the pseudo first and pseudo second order equation models. Experimental data fitted to pseudo second order model, supporting the assumption that the adsorption is due to chemisorption. Batch sorption tests were conducted and the results fitted to Langmuir and Freundlich sorption models. Both isotherm models chosen for this work did not fit to the experimental data. Thus, these are preliminary results and the studies must be repeated to evaluate data variability and better statistical inference. Other isotherm models must be evaluated to choose the best fitted one and describe the sorption of cobalt on bentonite in oil matrix. Even though, bentonite has considerable potential as sorbent for the removal of cobalt from lubricant oil. Finally, the results might be extended to other kinds of radioactive oils and radioactive organic wastes. (author)

Cobalt-60 production in CANDU reactors

International Nuclear Information System (INIS)

Ross, Michel; Lemire, Christian

2002-01-01

CANDU reactors can produce cobalt-60 very efficiently and with an interesting return on investment. This paper discusses what is needed to convert a CANDU reactor into a cobalt-60 producer: what are the different phases, the safety studies required, the physical modifications needed, and what is the minimum involvement of the utility owning the plant. The past ten years of experience of Hydro-Quebec as a cobalt-60 producer will be reviewed, including the management of the risk of both incident and electricity generation loss, and including the benefits for the utility and its personnel. Originally a simple metal used for centuries as a pigment, cobalt-59 today is transformed into cobalt-60, a radioactive element of unprecedented value. Well known in medicine for cancer treatment, cobalt-60 is also used to sterilize a wide range of disposable medical products used in hospitals and to sanitize pharmaceutical and cosmetic products. Cobalt-60 is proving to be a new and effective solution, in the food sector, for preserving harvests and controlling food-borne diseases, or to advantageously replace certain gases and chemical products which are suspected of being harmful or carcinogenic. There are also other applications, such as: hardening of some plastics, treatment of sewage sludge and elimination of harmful insect populations. With a half-life of 5,3 years, cobalt-60 is a metal not found in nature. It is a radioactive isotope produced by exposing stable nuclei of cobalt-59 to neutrons. One of the best places to find such an important neutron source is a nuclear reactor. High energy gamma rays are then emitted during the process of radioactive decay, where cobalt-60 seeks again its stable state

Evaluation and selection of aqueous-based technology for partitioning radionuclides from ICPP calcine

International Nuclear Information System (INIS)

Olson, A.L.; Schulz, W.W.; Burchfield, L.A.; Carlson, C.D.; Swanson, J.L.; Thompson, M.C.

1993-02-01

Early in 1993 Westinghouse Idaho Nuclear Company (WINCO) chartered a Panel of Nuclear Separations Experts. The purpose of this Panel was to assist WINCO scientists and engineers in selecting, evaluating, and ranking candidate aqueous-based processes and technologies for potential use in partitioning selected radionuclides from nitric acid solutions of retrieved Idaho Chemical Processing Plant (ICPP) calcine. Radionuclides of interest are all transuranium elements, 90 Sr, 99 Tc, 129 I, and 137 Cs. The six man Panel met for 4 days (February 16--19, 1993) on the campus of the Idaho State University in Pocatello, Idaho. Principal topics addressed included: Available radionuclide removal technology; applicability of separations technology and processes to ICPP calcine; and potential integrated radionuclide partitioning schemes. This report, prepared from contributions from all Panel members, presents a comprehensive account of the proceedings and significant findings of the February, 1993 meeting in Pocatello

Sequential determination of important ecotoxic radionuclides in nuclear waste samples

International Nuclear Information System (INIS)

Bilohuscin, J.

2016-01-01

In the dissertation thesis we focused on the development and optimization of a sequential determination method for radionuclides 93 Zr, 94 Nb, 99 Tc and 126 Sn, employing extraction chromatography sorbents TEVA (R) Resin and Anion Exchange Resin, supplied by Eichrom Industries. Prior to the attestation of sequential separation of these proposed radionuclides from radioactive waste samples, a unique sequential procedure of 90 Sr, 239 Pu, 241 Am separation from urine matrices was tried, using molecular recognition sorbents of AnaLig (R) series and extraction chromatography sorbent DGA (R) Resin. On these experiments, four various sorbents were continually used for separation, including PreFilter Resin sorbent, which removes interfering organic materials present in raw urine. After the acquisition of positive results of this sequential procedure followed experiments with a 126 Sn separation using TEVA (R) Resin and Anion Exchange Resin sorbents. Radiochemical recoveries obtained from samples of radioactive evaporate concentrates and sludge showed high efficiency of the separation, while values of 126 Sn were under the minimum detectable activities MDA. Activity of 126 Sn was determined after ingrowth of daughter nuclide 126m Sb on HPGe gamma detector, with minimal contamination of gamma interfering radionuclides with decontamination factors (D f ) higher then 1400 for 60 Co and 47000 for 137 Cs. Based on the acquired experiments and results of these separation procedures, a complex method of sequential separation of 93 Zr, 94 Nb, 99 Tc and 126 Sn was proposed, which included optimization steps similar to those used in previous parts of the dissertation work. Application of the sequential separation method for sorbents TEVA (R) Resin and Anion Exchange Resin on real samples of radioactive wastes provided satisfactory results and an economical, time sparing, efficient method. (author)

Preparation of modified polymer- Alumino silicate composite and their application in removal of some radionuclides from aqueous solutions

International Nuclear Information System (INIS)

El- Masry, E.H.

2012-01-01

Ion exchange is one of the most common and effective treatment methods for radioactive liquid waste. This technique is well developed and has been employed for many years in both the nuclear industry and in other industries. In this thesis polyacrylamide- zeolite and polyacrylamide- bentonite composites were prepared and characterized using advanced analytical techniques. The prepared materials were used as composite ion exchangers for removal of Cesium, Cobalt and Strontium ions from simulated waste solution. Effect of ph of the medium on the removal of aforementioned ions was investigated. The sorption kinetic was studied and the data were analyzed by different kinetic models which rivaled that the mechanism of the sorption processes is mainly controlled by pseudo-second order reaction, and particle diffusion might be involved in the sorption processes. The values of diffusion coefficient of the three metal ions were calculated and suggested that chemisorption was the predominated sorption mechanism. Several isotherm models were applied for the sorption, and thermodynamic parameters were determined. The positive values of enthalpy change, δH, for the three metal ions confirmed the endothermic nature of the sorption processes. The results indicated that the prepared materials can be used as efficient ion exchange materials for the removal of cesium, cobalt and strontium ions from simulated waste solution. In the present study, immobilization of polyacrylamide- zeolite and/ or polyacrylamide- bentonite composites loaded with cesium, cobalt and/or strontium radionuclides with Ordinary Portland Cement (OPC) has been carried out. Several factors affecting the characteristics of the final solidified waste product towards safe disposal such as mechanical strength and leaching behavior of the radioisotopes have been studied. The obtained results showed that the presence of polyacrylamide- zeolite and/ or polyacrylamide- bentonite composites in the cemented wastes

Disciplinary reinforcement of separation and immobilization of radionuclides. Survey of present and required knowledge

International Nuclear Information System (INIS)

Comans, R.N.J.; Prij, J.; Konings, R.J.M.; Woittiez, J.R.W.

1996-11-01

An overview of the knowledge and technical possibilities within the units Nuclear Energy, Radiation Technology, and Fossil Fuels of the Netherlands Energy Research Foundation (ECN) in the fields of separation and immobilization, including the geochemical behavior, of radionuclides, is given. The aim of the survey is to maintain the competence at ECN in this field, to better serve the present market in the future, and to explore potential, new markets, all by means of a disciplinary-oriented development. From the results of the survey it appears that the present knowledge and technical know-how at the three units is complementary and that there are good options to strengthen the position of ECN, in particular in the working areas back-end of the nuclear fuel cycle, and the post trajectory of the decontamination activities (actinide migration in the geosphere and the biosphere, assessment of the effectiveness of immobilization of fissionable materials with respect to recycling, leaching performance of waste containers and natural radioisotopes in solid waste, produced by the group Decontamination and Radioactive Waste Processing (DRA, abbreviated in Dutch) and a modelled description, health effects of radiation. Recommendations are given how the required knowledge reinforcement can be realized. 59 refs

Half-lives of some radionuclides

International Nuclear Information System (INIS)

Lagoutine, F.; Legrand, J.; Bac, C.

1978-01-01

The half-lives of nine radionuclides have been determined, and the results are as follows: 56 Co:77.12 +- 0.20 days: 67 Ga: 78.33 +- 0.10 hr; 90 Sr: 28.15 +- 0.10 years; sup(103m)Rh: 56.112 +- 0.028mn; 111 In: 2.802 +- 0.003 days; sup(125m)Te: 57.40 +- 0.15 days; 131 I: 8.020 +- 0.003 days; 139 Ce: 137.59 +- 0.12 days; 152 Eu: 13.10 +- 0.15 years. The results are compared with the most recent values in the literature. (author)

Electrocatalytic performance evaluation of cobalt hydroxide and cobalt oxide thin films for oxygen evolution reaction

Science.gov (United States)

Babar, P. T.; Lokhande, A. C.; Pawar, B. S.; Gang, M. G.; Jo, Eunjin; Go, Changsik; Suryawanshi, M. P.; Pawar, S. M.; Kim, Jin Hyeok

2018-01-01

The development of an inexpensive, stable, and highly active electrocatalyst for oxygen evolution reaction (OER) is essential for the practical application of water splitting. Herein, we have synthesized an electrodeposited cobalt hydroxide on nickel foam and subsequently annealed in an air atmosphere at 400 °C for 2 h. In-depth characterization of all the films using X-ray diffraction (XRD), X-ray photoelectron emission spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV) techniques, which reveals major changes for their structural, morphological, compositional and electrochemical properties, respectively. The cobalt hydroxide nanosheet film shows high catalytic activity with 290 mV overpotential at 10 mA cm-2 and 91 mV dec-1 Tafel slope and robust stability (24 h) for OER in 1 M KOH electrolyte compared to cobalt oxide (340 mV). The better OER activity of cobalt hydroxide in comparison to cobalt oxide originated from high active sites, enhanced surface, and charge transport capability.

Sol-gel preparation of cobalt manganese mixed oxides for their use as electrode materials in lithium cells

International Nuclear Information System (INIS)

Lavela, P.; Tirado, J.L.; Vidal-Abarca, C.

2007-01-01

An ethanol dehydration procedure has been used to precipitate gel-like citrate precursors containing cobalt and manganese transition metal ions. Further annealing led to the Mn x Co 3-x O 4 spinel oxide series (x: 1, 1.5, 2, 3). Annealing temperature and treatment time were also evaluated to optimize the performance of the oxides as active electrode materials in lithium cells. The manganese-cobalt mixed oxides obtained by this procedure were cubic or tetragonal phases depending on the cobalt content. SEM images showed spherical macroporous aggregates for MnCo 2 O 4 and hollow spheres for manganese oxides. The galvanostatic cycling of lithium cells assembled with these materials demonstrated a simultaneous reduction of cobalt and manganese during the first discharge and separation of cobalt- and manganese-based products on further cycling. As compared with binary manganese oxides, a notorious electrochemical improvement was observed in the mixed oxides. This behavior is a consequence of the synergistic effect of both transition metal elements, associated with the in-situ formation of a nanocomposite electrode material when cobalt is introduced in the manganese oxide composition. Values higher than 400 mAh/g were sustained after 50 cycles for MnCo 2 O 4

Rapid instrumental and separation methods for monitoring radionuclides in food and environmental samples. Final report on an IAEA co-ordinated research programme

International Nuclear Information System (INIS)

1995-01-01

The Co-ordinated Research Programme (CRP) on Rapid Instrumental and Separation Methods for Monitoring Radionuclides in Food and Environmental Samples was established by the Agency following a Consultants' Meeting on the same topic, which was held 5-9 September 1988 in Vienna. It was completed in 1992. At various times during its course it encompassed 15 participants from 14 countries. The scope of work and objectives of the CRP were established at the Consultants' Meeting. It was agreed that the CRP should focus on the development of rapid methods for the determination of radionuclides in food and environmental samples during the intermediate and late post-accident phases. The rapid methods developed during the course of the CRP were intended to permit a timely and accurate determination of radionuclides at concentrations at least one order of magnitude below those specified for Derived Intervention Levels (DILs) for food by the WHO/FAO and the IAEA. Research Co-ordination meetings were held in Warsaw, Poland in September 1989 and in Vienna, Austria in 1991. Reports of the meetings are available from the Agency on Request. This document comprises copies of final reports from the participants and selected contributions presented by the participants at the meetings. The contributions were selected on the basis of being able to stand alone, without further explanation. Where there was an overlap in the information presented by a participant at both meetings, the most complete contribution was selected

Rapid instrumental and separation methods for monitoring radionuclides in food and environmental samples. Final report on an IAEA co-ordinated research programme

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

The Co-ordinated Research Programme (CRP) on Rapid Instrumental and Separation Methods for Monitoring Radionuclides in Food and Environmental Samples was established by the Agency following a Consultants' Meeting on the same topic, which was held 5-9 September 1988 in Vienna. It was completed in 1992. At various times during its course it encompassed 15 participants from 14 countries. The scope of work and objectives of the CRP were established at the Consultants' Meeting. It was agreed that the CRP should focus on the development of rapid methods for the determination of radionuclides in food and environmental samples during the intermediate and late post-accident phases. The rapid methods developed during the course of the CRP were intended to permit a timely and accurate determination of radionuclides at concentrations at least one order of magnitude below those specified for Derived Intervention Levels (DILs) for food by the WHO/FAO and the IAEA. Research Co-ordination meetings were held in Warsaw, Poland in September 1989 and in Vienna, Austria in 1991. Reports of the meetings are available from the Agency on Request. This document comprises copies of final reports from the participants and selected contributions presented by the participants at the meetings. The contributions were selected on the basis of being able to stand alone, without further explanation. Where there was an overlap in the information presented by a participant at both meetings, the most complete contribution was selected.

Cobalt sensitization and dermatitis

DEFF Research Database (Denmark)

Thyssen, Jacob P

2012-01-01

: This clinical review article presents clinical and scientific data on cobalt sensitization and dermatitis. It is concluded that cobalt despite being a strong sensitizer and a prevalent contact allergen to come up on patch testing should be regarded as a very complex metal to test with. Exposure...

Radionuclide distributions and migration mechanisms at shallow land burial sites. 1982 annual report of research investigations on the distribution, migration and containment of radionuclides at Maxey Flats, Kentucky

International Nuclear Information System (INIS)

Kirby, L.J.

1984-02-01

Subsurface waters at Maxey Flats are anoxic, have a high alkalinity and contain high concentrations of ferrous, sulfide and ammonium ions and organic carbon. The trench leachates are extremely variable in composition. Prominent radionuclides include 3 H, 60 Co, 90 Sr, 137 Cs, 238 239 240 Pu and 241 Am. A wide spectrum of dissolved organic compounds is present in the leachates, including EDTA, polar organics and decomposition products from the waste forms. Cobalt-60 and plutonium are present as EDTA complexes and 90 Sr and 137 Cs are associated with carboxylic acid type compounds. The chemistry of these waters changes drastically as they become oxic and plutonium becomes less mobile under these new conditions. Water enters the trenches by infiltration through the trench caps, through subsidence areas, and through interfaces between new landfill and the original soil. Lateral flow is very complex and slow, and apparently occurs mainly by fracture flow. The plastic infiltration barrier installed in 1981 to 1982 has been effective in reducing soil moisture if cracks and leaks are eliminated. To date, no direct evidence of radionuclide transport to offsite locations by subsurface flow has been confirmed. The offsite distribution of radionuclides, except for tritium, is comparable to the ambient fallout from nuclear weapons testing. Tritium concentrations in water offsite are orders of magnitude below MPC levels. 24 figures, 31 tables

Cobalt 60 availability for radiation processing

International Nuclear Information System (INIS)

Fraser, F.M.

1986-01-01

In the last 20 years, the steady and significant growth in the application of radiation processing to industrial sterilization has been seen. The principal application of this technology is the sterilization of disposable medical products, food irradiation, the irradiation of personal care goods and so on. At present, more than 70 million curies of cobalt-60 supplied by Atomic Energy of Canada Ltd. have been used for gamma processing in these applications. This is estimated to be more than 80 % of the total cobalt-60 in service in the world. Commercial food irradiation has an exciting future, and as to the impact of food irradiation on the availability of cobalt-60 over the next ten years, two principal factors must be examined, namely, the anticipated demand for cobalt-60 in all radiation processing applications, and the supply of cobalt-60 to reliably meet the expected demand. As for the cobalt-60 in service today, 90 % is used for the sterilization of disposable medical products, 5 % for food irradiation, and 5 % for other application. The demand for up to 30 million curies of cobalt-60 is expected over the next 10 years. Today, it is estimated that over 150,000 tons of spices, fruit and fish are irradiated. The potential cobalt-60 production could exceed 110 million curies per year. Gamma processing application will demand nearly 50 million curies in 1990. (Kako, I.)

Diagnostic Value of the Cobalt (58Co) Excretion Test in Iron Deficiency Anemia

International Nuclear Information System (INIS)

Sihn, Hyun Chung; Hong, Kee Suck; Cho, Kyung Sam; Song, In Kyung; Koh, Chang Soon; Lee, Mun Ho

1976-01-01

The diagnosis of iron deficiency rests upon the correct evaluation of body iron stores. Morphological interpretation of blood film and the red cell indices are not reliable and often absent in mild iron deficiency. Serum iron levels and iron-binding capacity are more sensitive indices of iron deficiency, but they are often normal in iron depletion and mild iron deficiency anemia. They are also subject ro many variables which may introduce substantial errors and influenced by many pathologic and physiologic states. Examination of the bone marrow aspirate for stainable iron has been regarded as one of the most sensitive and reliable diagnostic method for detecting iron deficiency, but this also has limitations. Thus, there is still need for a more practical, but sensitive and reliable substitute as a screening test of iron deficiency. Pollack et al. (1965) observed that the intestinal absorption of cobalt was raised in iron, deficient rats and Valberg et al. (1969) found that cobalt absorption was elevated in patients with iron deficiency. A direct correlation was demonstrated between the amounts of radioiron and radiocobalt absorbed. Unlike iron, excess cobalt was excreted by the kidney, the percentage of radioactivity in the urine being directly related to the percentage absorbed from the gastro-intestinal tract. Recently a test based on the urinary excretion of an oral dose of 57 Co has been proposed as a method for detecting iron deficiency. To assess the diagnostic value of urinary cobalt excretion test cobaltous chloride labelled with 1 μCi of 58 Co was given by mouth and the percentage of the test dose excreted in the urine was measured by a gamma counter. The mean 24 hour urinary cobalt excretion in control subjects with normal iron stores was 6.1%(1.9-15.2%). Cobalt excretion was markedly increased in patients with iron deficiency and excreted more than 29% of the dose. In contrast, patients with anemia due to causes other than iron deficiency excreted less

Creep fatigue of low-cobalt superalloys: Waspalloy, PM U 700 and wrought U 700

Science.gov (United States)

Leis, B. N.; Rungta, R.; Hopper, A. T.

1983-01-01

The influence of cobalt content on the high temperature creep fatigue crack initiation resistance of three primary alloys was evaluated. These were Waspalloy, Powder U 700, and Cast U 700, with cobalt contents ranging from 0 up to 17 percent. Waspalloy was studied at 538 C whereas the U 700 was studied at 760 C. Constraints of the program required investigation at a single strain range using diametral strain control. The approach was phenomenological, using standard low cycle fatigue tests involving continuous cycling tension hold cycling, compression hold cycling, and symmetric hold cycling. Cycling in the absence of or between holds was done at 0.5 Hz, whereas holds when introduced lasted 1 minute. The plan was to allocate two specimens to the continuous cycling, and one specimen to each of the hold time conditions. Data was taken to document the nature of the cracking process, the deformation response, and the resistance to cyclic loading to the formation of small cracks and to specimen separation. The influence of cobalt content on creep fatigue resistance was not judged to be very significant based on the results generated. Specific conclusions were that the hold time history dependence of the resistance is as significant as the influence of cobalt content and increased cobalt content does not produce increased creep fatigue resistance on a one to one basis.

Development and implementation of the waste diversion program at MDS Nordion's Cobalt Operations Facility

International Nuclear Information System (INIS)

Wasiak, T.

2004-01-01

Historically, the MDS Nordion (MDSN) Cobalt Operations Facility sent solid waste for disposal to Atomic Energy of Canada Ltd.'s Chalk River Laboratories (AECL-CRL). A large portion of this waste was not contaminated. Because this non-contaminated waste originated in the 'active area' of the MDSN facility, it was routinely disposed of as low-level active waste. In 2002, MDSN undertook an initiative to develop and implement a more sophisticated and more economical waste management program. The Waste Diversion Program (WDP) ensures continued environmental and public protection, and reduces the demand on Canada's limited capacity for storage of radioactive material and the associated operating costs. The goal of the WDP is to reduce the volume of waste currently being shipped to AECL-CRL's Waste Management Operation as low-level active waste. The presentation discusses key elements of both the development and the implementation of WDP. It focuses on the following areas: the regulatory environment surrounding the waste disposal issues in Canada and abroad. Methods used by MDSN for determination of radionuclides, which could be present in the facility. Choice of equipment and calculation of individual alarm levels for each identified radionuclide. Key elements of the practical implementation of the program. CNSC Regulatory approval process. The bottom line - dollars and cents. The primary objective of the WDP is to ensure that only waste, which meets regulatory requirements, is diverted from the solid active waste stream. This has been successfully accomplished in MDSN's Cobalt Operations Facility. The objective of the presentation is to share the knowledge and experience obtained in the development process, and thus provide a guideline for other nuclear facilities interested in establishing similar proactive and cost effective programs. (author)

Speciation and transport of radionuclides in ground water

International Nuclear Information System (INIS)

Robertson, D.E.; Toste, A.P.; Abel, K.H.; Cowan, C.E.; Jenne, E.A.; Thomas, C.W.

1984-01-01

Studies of the chemical speciation of a number of radionuclides migrating in a slightly contaminated ground water plume are identifying the most mobile species and providing an opportunity to test and/or validate geochemical models of radionuclide transport in ground waters. Results to date have shown that most of the migrating radionuclides are present in anionic or nonionic forms. These include anionic forms of 55 Fe, 60 Co, /sup 99m/Tc, 106 Ru, 131 I, and nonionic forms of 63 Ni and 125 Sb. Strontium-70 and a small fraction of the mobile 60 Co are the only cationic radionuclides which have been detected moving in the ground water plume beyond 30 meters from the source. A comparison of the observed chemical forms with the predicted species calculated from modeling thermodynamic data and ground water chemical parameters has indicated a good agreement for most of the radioelements in the system, including Tc, Np, Cs, Sr, Ce, Ru, Sb, Zn, and Mn. The discrepancies between observed and calculated solutions species were noted for Fe, Co, Ni and I. Traces of Fe, Co, and Ni were observed to migrate in anionic or nonionic forms which the calculations failed to predict. These anionic/nonionic species may be organic complexes having enhanced mobility in ground waters. The radioiodine, for example, was shown to behave totally as an anion but further investigation revealed that 49-57% of this anionic iodine was organically bound. The ground water and aqueous extracts of trench sediments contain a wide variety of organic compounds, some of which could serve as complexing agents for the radionuclides. These results indicate the need for further research at a variety of field sites in defining precisely the chemical forms of the mobile radionuclide species, and in better understanding the role of dissolved organic materials in ground water transport of radionuclides

Purification of radionuclides for nuclear medicine

International Nuclear Information System (INIS)

Horwitz, E.P.; Bond, A.H.

2002-01-01

Novel systems for the rapid separation of 67 Cu, 90 Y, 188 Re, 212 Bi, 213 Bi, and 223 Ra are described. To achieve the high levels of decontamination required of radionuclides used in radioimmunotherapy, we have utilised combinations of ion exchange (IX) and novel extraction chromatographic (EXC) resins. The objective of each separation system is to remove by many orders of magnitude the parent isotopes and to reduce the concentrations of stable, sometimes adventitious impurities, to low levels. The latter objective is particularly important to achieve a high degree of bonding of radionuclide onto a monoclonal antibody. The purification of 212 Bi (60.6 min half-life) furnishes a good example of the level of purity that we have achieved using tandem combinations of EXC and IX resins. Bismuth-212 was separated from its daughters, 212 Pb, 224 Ra, 228 Th and 232 U at the 50 mCi level. The resultant 212 Bi decayed to background in a few days indicative of high purity. Another example of extraordinary removal of parent nuclide from daughter nuclide and subsequent purification of daughter from stable elements is the preparation of 90 Y. Strontium-90 was removed from 90 Y by > 10 9 . The purified 90 Y uptake by monoclonal antibodies was close to 100%

Remedial action of matrices contaminated by cobalt with supercritical CO_2: contribution to the understanding of the complex formation mechanisms and to the diphasic transfers

International Nuclear Information System (INIS)

Gervais, Florence

2001-01-01

Soils rehabilitation using supercritical CO_2 seems an interesting alternative way to existing techniques. No effluents are generated during the supercritical fluid extraction, which is the main advantage of this process. In order to be extracted by this techniques, metals or radionuclides have to be complexed by suitable chelating agents. Beta-diketones and dithiocarbamates (fluorinated or not) have been chosen. The first part of this work deals with chemical equilibria mechanisms study in an aqueous phase. Experiments show a very weak cobalt complexation kinetics with acetylacetone. Moreover, this complex exhibit a hydrophilic behaviour. On the other hand, cobalt and dithiocarbamate instantaneously from a chelate which is very hydrophobic. Mass transfer between extracting and aqueous phases (hexane and SC CO_2) are also investigated. Supercritical CO_2 seems to have a greater affinity towards fluorinated beta-diketones than hexane. This tendency is confirmed by in situ commercial chelates (fluorinates or not) solubility measurements using X-ray absorption spectroscopy. However, cobalt-beta-diketonates are hydrophilic because of their partial hydration. This kind of chelating agents is not suitable to cobalt supercritical fluid extraction from an aqueous phase. Inversely, distribution coefficients of hydrophobic dithiocarbamates are higher than beta-diketonates, whatever the extracting solvent is. Metals extraction from an aqueous matrix seems possible with these chelating agents. (author) [fr

Nitrogen-doped carbon-supported cobalt-iron oxygen reduction catalyst

Science.gov (United States)

Zelenay, Piotr; Wu, Gang

2014-04-29

A Fe--Co hybrid catalyst for oxygen reaction reduction was prepared by a two part process. The first part involves reacting an ethyleneamine with a cobalt-containing precursor to form a cobalt-containing complex, combining the cobalt-containing complex with an electroconductive carbon supporting material, heating the cobalt-containing complex and carbon supporting material under conditions suitable to convert the cobalt-containing complex and carbon supporting material into a cobalt-containing catalyst support. The second part of the process involves polymerizing an aniline in the presence of said cobalt-containing catalyst support and an iron-containing compound under conditions suitable to form a supported, cobalt-containing, iron-bound polyaniline species, and subjecting said supported, cobalt-containing, iron bound polyaniline species to conditions suitable for producing a Fe--Co hybrid catalyst.

Reappraisal of radionuclide liver scans for preoperative gastric cancer patients

Energy Technology Data Exchange (ETDEWEB)

Kondo, Makoto; Yonahara, Yoshio; Yamashita, Shoji; Ando, Yutaka; Mohri, Makoto [National Second Hospital of Tokyo (Japan)

1983-04-01

Radionuclide liver scans were obtained in 89 preoperative patients with gastric cancer. Eight showed definite defects on liver scans. At laparotomy, 14 patients were found to have liver involvement secondary to gastric cancer. The sensitivity of liver scans to predict liver involvement is 57% (8/14), and the specificity is 100% (75/75). The patients with definite defects on liver scans had a lower rate of palliative resection of the primary tumors (2/8) than the patients with liver involvement and no scan abnormality (4/6). The patients with advanced lesions but without liver involvement had the highest probability of resecting the primary tumors (57/63 : 47 radical, and 10 palliative). Normal serum levels of liver chemistries did not preclude the presence of defects on liver scans. Additional three patients were found to have cirrhosis of the liver solely based on liver scans, which was confirmed at laparotomy. Radionuclide liver scans can predict liver involvement with very few false positives, and may discriminate patients unsuitable for laparotomy even with palliative intent.

Effect of fluoride and cobalt on forming enamel: scanning electron microscope and X-ray microanalysis study

International Nuclear Information System (INIS)

Ashrafi, S.H.; Eisenmann, D.R.; Zaki, A.E.; Liss, R.

1988-01-01

The forming surfaces of enamel of rat incisors were examined by scanning electron microscope one hour after injection of either 5 mg/100 g body weight of sodium fluoride or 12 mg/100 g body weight of cobalt chloride. The cell debris from the surfaces of the separated incisors was either gently wiped off with soft facial tissues or chemically removed by treating with NaOH, NaOCl or trypsin. Best results to remove cell debris were obtained from 0.25% trypsin treatment. SEM studies revealed that the surface of the normal secretory enamel was characteristic in appearance with well-developed smooth prism outlines. In fluoride specimens the prism outlines were feathery in appearance, laced with protruding spine-shaped clusters of mineral crystals. In the case of cobalt treatment, prism outlines were less uniform and in some areas they were incomplete. The calcium concentration of surface enamel was significantly lower in the cobalt-treated specimens than those from control and fluoride-treated animals. The Ca:Mg ratio was also lower in cobalt-treated specimens as compared to control and fluoride-treated ones

Synthesis of new cobalt aluminophosphate framework by opening a cobalt methylphosphonate layered material

Czech Academy of Sciences Publication Activity Database

Zaarour, M.; Pérez, O.; Boullay, P.; Martens, J.; Mihailova, B.; Karaghiosoff, K.; Palatinus, Lukáš; Mintova, S.

2017-01-01

Roč. 19, č. 34 (2017), s. 5100-5105 ISSN 1466-8033 Institutional support: RVO:68378271 Keywords : cobalt aluminophosphate * cobalt methylphosphonate * layered materials * crystallic structure * X-ray diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.474, year: 2016

Radio cobalt in French rivers

International Nuclear Information System (INIS)

Lambrechts, A.; Baudin-Jaulent, Y.

1996-01-01

The isotopes 58 and 60 of cobalt present in liquid wastes from nuclear plants or from fuel reprocessing plant of Marcoule are fixed in the different compartments of French rivers. The activity levels of radio-cobalt vary according to the sampled compartments nature (bryophyta > immersed plants > sediment > fish). Elsewhere, laboratory experimentations show that the contamination of fish occurs essentially from the water way rather than from food. Cobalt is mainly fixed by kidneys; muscles is no more than 30 % of the total fish activity. (author)

Molecular mechanics calculations on cobalt phthalocyanine dimers

NARCIS (Netherlands)

Heuts, J.P.A.; Schipper, E.T.W.M.; Piet, P.; German, A.L.

1995-01-01

In order to obtain insight into the structure of cobalt phthalocyanine dimers, molecular mechanics calculations were performed on dimeric cobalt phthalocyanine species. Molecular mechanics calculations are first presented on monomeric cobalt(II) phthalocyanine. Using the Tripos force field for the

UNDERWATER ANALYSIS OF IRRADIATED REACTOR SLUGS FOR Co-60 AND OTHER RADIONUCLIDES AT THE SAVANNAH RIVER SITE

International Nuclear Information System (INIS)

CASELLA, VITO

2004-01-01

Co-60 was produced in the Savannah River Site (SRS) reactors in the 1970s, and the irradiated cobalt reactor slugs were stored in a reactor basin at SRS. Since the activity rates of these slugs were not accurately known, assaying was required. A sodium iodide gamma detector was placed above a specially designed air collimator assembly, so that the slug was eight to nine feet from the detector and was shielded by the basin water. Also, 18 curium sampler slugs, used to produce Cm-244 from Pu-239, were to be disposed of with the cobalt slugs. The curium slugs were also analyzed with a High Purity Germanium (HPGE) detector in an attempt to identify any additional radionuclides produced from the irradiation. Co-60 concentrations were determined for reactor disassembly basin cobalt slugs and the 18 curium sampler slugs. The total Co-60 activity of all of the assayed slugs in this work summed to 31,783 curies on 9/15/03. From the Co-60 concentrations of the curium sampler slugs, the irradiation flux was determined for the known irradiation time. The amounts of Pu-238,-239,-240,-241,-242; Am-241,-243; and Cm-242,-244 produced were then obtained based on the original amount of Pu-239 irradiated

Extraction of cobalt ion from textile using a complexing macromolecular surfactant in supercritical carbon dioxide

International Nuclear Information System (INIS)

Chirat, Mathieu; Ribaut, Tiphaine; Clerc, Sebastien; Lacroix-Desmazes, Patrick; Charton, Frederic; Fournel, Bruno

2013-01-01

Cobalt ion under the form of cobalt nitrate is removed from a textile lab coat using supercritical carbon dioxide extraction. The process involves a macromolecular additive of well-defined architecture, acting both as a surfactant and a complexing agent. The extraction efficiency of cobalt reaches 66% when using a poly(1,1,2,2-tetrahydroperfluoro-decyl-acrylate-co-vinyl-benzylphosphonic diacid) gradient copolymer in the presence of water at 160 bar and 40 C. The synergy of the two additives, namely the copolymer and water which are useless if used separately, is pointed out. The potential of the supercritical carbon dioxide process using complexing macromolecular surfactant lies in the ability to modulate the complexing unit as a function of the metal as well as the architecture of the surface-active agent for applications ranging for instance from nuclear decontamination to the recovery of strategic metals. (authors)

AN ELECTROPLATING METHOD OF FORMING PLATINGS OF NICKEL, COBALT, NICKEL ALLOYS OR COBALT ALLOYS

DEFF Research Database (Denmark)

1997-01-01

An electroplating method of forming platings of nickel, cobalt, nickel alloys or cobalt alloys with reduced stresses in an electrodepositing bath of the type: Watt's bath, chloride bath or a combination thereof, by employing pulse plating with periodic reverse pulse and a sulfonated naphthalene...

Hydrology and Radionuclide Migration Program, 1985--1986 progress report

International Nuclear Information System (INIS)

Buddemeier, R.W.

1988-09-01

This report presents results from the Lawrence Livermore National Laboratory's participation in the Hydrology and Radionuclide Migration Program (formerly the Radionuclide Migration Project) at the Nevada Test Site (NTS) during fiscal years 1985 and 1986. The report discusses studies of the partitioning and movement of dissolved and colloidal radionuclides at the Cheshire (U20n) site; tracer studies of shallow recharge and of plant-water uptake at the Cambric-site ditch carrying the effluent water pumped from well RNM-2; development of a rapid and sensitive assay for 99 Tc in groundwater and its application to a survey of technetium activities at a variety of test wells; and a series of methodological studies directed toward calibration, understanding, and improving our low-level radionuclide determinations. Groundwater sampled from the Cheshire cavity and from adjacent aquifers contains substantial concentrations (mg/L) of colloids that appear to consist primarily of natural minerals. These colloids were found to contain detectable amounts of strongly sorbed radionuclides, leading to the hypothesis that radionuclides are being transported by the groundwater in colloidal form. The RNM ditch at the Cambric site has provided a unique tritium-labeled, irrigated test plot in the desert. One study at this site continued earlier investigations of water and tritium migration in the shallow vadose (unsaturated-soil) zone adjacent to the ditch and extended that study to include using a tracer to determine the velocity of vertical water flow in the recharge zone directly below the ditch. 57 refs., 15 figs., 23 tabs

Preparation of high purity cobalt

International Nuclear Information System (INIS)

Isshiki, M.; Fukuda, Y.; Igaki, K.

1985-01-01

A combination of anion exchange separation, electrolytic extraction, floating zone refining and dry hydrogen treatment was used to purify cobalt. The effectiveness of each purification process was confirmed by measurements of the residual resistivity ratio (RRR) and activation analyses. Proton activation analysis revealed that all the main metallic impurities except iron were effectively removed by a combination of these processes. The effective removal of oxygen, nitrogen and carbon by dry hydrogen treatment was confirmed by activation analyses using 3 He ion beams, proton beams and γ rays. It was found that the rate-controlling step in the decarburization process was a surface reaction. The maximum RRR obtained for the purified specimen was 334, which is higher than previously reported values. (Auth.)

Study of complex formation of cobalt (II) and cobalt (III) in acrylamide aqueous solutions and in the phase of acrylamide hydrogel

International Nuclear Information System (INIS)

Ismailova, M.M.; Egorova, L.A.; Khamidov, B.O.

1993-01-01

Present article is devoted to study of complex formation of cobalt (II) and cobalt (III) in acrylamide aqueous solutions and in the phase of acrylamide hydrogel. The condition of cobalt in various rate of oxidation in acrylamide aqueous solutions was studied. The concentration conditions of stability of system Co(II)-Co(III) were defined. The composition of coordination compounds of cobalt (II) and cobalt (III) in acrylamide aqueous solutions and in the phase of acrylamide hydrogel was determined.

Applications of extraction chromatography in the development of radionuclide generator systems for nuclear medicine

International Nuclear Information System (INIS)

Dietz, M.L.; Horwitz, E.P.

2000-01-01

Numerous methods have been described for the separation and purification of radionuclides for application in diagnostic and therapeutic nuclear medicine, among them ion exchange, solvent extraction, and various forms of chromatography. Although extraction chromatography has previously been shown to provide a means of performing a number of separations of potential use in radionuclide generator systems, the application of the technique to generator development has thus far been limited. Recent work directed at improved methods for the determination of radionuclides in biological and environmental samples has led to the development of a series of novel extraction chromatographic resins exhibiting enhanced metal ion retention from strongly acidic media and excellent selectivity, among them materials suitable for the isolation of 212 Bi, 90 Y, and 213 Bi. These resins, along with extraction chromatographic materials employing functionalized supports to improve their physical stability or metal ion retention properties, are shown to offer promise in the development of improved radionuclide generators

Granulometric analysis of sediments containing transuranic radionuclides

International Nuclear Information System (INIS)

Smith, R.M.; Additon, M.K.

1980-11-01

A dry sieving technique using a sonic sifter was selected for the granulometric analysis of sediment samples containing radionuclide contamination. A sieve facility was established in the 234-5Z building for this purpose. Fifty-two contaminated sediment samples from the 216-Z-1A crib were sieved in the facility at a rate of two to four samples per day with no major problems. A comparison of particle size and radionuclide concentration indicated that there is no obvious benefit to particle size separation as a means of sediment decontamination, though an economic analysis will have to be conducted before a final decision can be made

Recovery of lithium and cobalt from waste lithium ion batteries of mobile phone

Energy Technology Data Exchange (ETDEWEB)

Jha, Manis Kumar, E-mail: mkjha@nmlindia.org; Kumari, Anjan; Jha, Amrita Kumari; Kumar, Vinay; Hait, Jhumki; Pandey, Banshi Dhar

2013-09-15

Graphical abstract: Recovery of valuable metals from scrap batteries of mobile phone. - Highlights: • Recovery of Co and Li from spent LIBs was performed by hydrometallurgical route. • Under the optimum condition, 99.1% of lithium and 70.0% of cobalt were leached. • The mechanism of the dissolution of lithium and cobalt was studied. • Activation energy for lithium and cobalt were found to be 32.4 kJ/mol and 59.81 kJ/mol, respectively. • After metal recovery, residue was washed before disposal to the environment. - Abstract: In view of the stringent environmental regulations, availability of limited natural resources and ever increasing need of alternative energy critical elements, an environmental eco-friendly leaching process is reported for the recovery of lithium and cobalt from the cathode active materials of spent lithium-ion batteries of mobile phones. The experiments were carried out to optimize the process parameters for the recovery of lithium and cobalt by varying the concentration of leachant, pulp density, reductant volume and temperature. Leaching with 2 M sulfuric acid with the addition of 5% H{sub 2}O{sub 2} (v/v) at a pulp density of 100 g/L and 75 °C resulted in the recovery of 99.1% lithium and 70.0% cobalt in 60 min. H{sub 2}O{sub 2} in sulfuric acid solution acts as an effective reducing agent, which enhance the percentage leaching of metals. Leaching kinetics of lithium in sulfuric acid fitted well to the chemical controlled reaction model i.e. 1 − (1 − X){sup 1/3} = k{sub c}t. Leaching kinetics of cobalt fitted well to the model ‘ash diffusion control dense constant sizes spherical particles’ i.e. 1 − 3(1 − X){sup 2/3} + 2(1 − X) = k{sub c}t. Metals could subsequently be separated selectively from the leach liquor by solvent extraction process to produce their salts by crystallization process from the purified solution.

Particle size and radionuclide levels in some west Cumbrian soils

International Nuclear Information System (INIS)

Livens, F.R.

1988-01-01

Four west Cumbrian soils of contrasting types, together with an estuarine silt sample, were separated into different particle size fractions by a combination of sieving and settling techniques. These sub-samples were analysed by quantitative gamma-ray spectrometry for several nuclides, principally 137 Cs, 106 Ru and 241 Am, followed by chemical separation and alpha spectrometric determination of 238,239,240 Pu. A simple empirical method of correction for differing sample sizes, and hence counting geometries, was developed for gamma spectrometry and found to give good results. The radionuclides were concentrated into the finer size fractions, with clay-sized ( 137 Cs from 3 to 35 times. The enhancement was greatest for all radionuclides in a sandy soil with a very low clay content (0.2% by weight) and it was found that, as the abundance of fine particles increased, so the concentration effect decreased. No evidence was found for a simple relationship between organic content and radionuclide activity, although the organic matter does have some effect. 17 refs.; 3 figs.; 6 tabs

Separation and quantitation of radionuclides in Hanford environmental and waste tank samples using IC-ICP/MS techniques

International Nuclear Information System (INIS)

Farmer, O.T. III; Smith, M.R.; Wyse, E.J.; Barinage, C.J.; Koppenaal, D.W.

1996-01-01

The use of shielded ICP/MS instrumentation to characterize radioactive material has seen marked growth over the past few years. With a lower limit detection now in the fg/mL range for newer units, ICP/MS has become the method of choice for many studies requiring rapid, isotopic analysis of both stable elements and radionuclides with half-lives greater than 102-103 years. However, despite its sensitivity and versatility, ICP/MS has heretofore had some notable limitations in certain radiological applications. For example, Hanford waste tank samples contain a variety of nuclides with altered isotopic abundances, which complicate identification of these nuclides. Even if a nuclide can be identified, conventional quantitation using vendor-supplied software assumes natural, or knowledge of, isotopic abundance. Difficult sample matrices like those obtained from the Hanford tanks can further complicate interpretation and quantitation. On-line ion chromatography (IC) has been recently employed to mitigate some these problems. By sequentially separating elements, isobars can be resolved, thereby permitting the unequivocal determination of isotopic abundances. But even though the technique resolves isobaric interferences and is effective in reducing matrix problems, IC does not easily lend itself to quantitation. Internal standards, which are crucial for quantitation during a prolonged ICP/MS analysis with varying eluant matrices, are separated or affected as any indigenous element is using standard IC methodology

Phosphorus introduction mechanism in electrodeposited cobalt films

International Nuclear Information System (INIS)

Kravtchenko, Jean-Francois

1973-01-01

The cathodic reduction of hypophosphite, phosphite and phosphate ions was studied using chrono-potentiometry and voltammetry. Then cobalt was deposited at constant current from a bath containing one of these three compounds. The current, while giving an electrodeposition of cobalt, also enhances at the same time a chemical deposition of cobalt. It is shown that high coercive forces in cobalt films are much more related to this chemical deposition than to the simple fact that the films contain some phosphorus. (author) [fr

Cobalt reduction of NSSS valve hardfacings for ALARA

Energy Technology Data Exchange (ETDEWEB)

Kim, Joo Hak; Lee, Sang Sub [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-07-01

This report informs NSSS designer that replacement of materials is one of the major means of ALARA implementation, and describes that NSSS valves with high-cobalt hardfacing are significant contributors to post-shutdown radiation fields caused by activation of cobalt-59 to cobalt-60. Generic procedures for implementing cobalt reduction programs for valves are presented. Discussions are presented of the general and specific design requirements for valve hardfacing in nuclear service. The nuclear safety issues involved with changing valve hardfacing materials are discussed. The common methods used to deposit hardfacing materials are described together with an explanation of the wear measurements. Wear resistance, corrosion resistance, friction coefficient, and mechanical properties of candidate hardfacing alloys are given. World-wide nuclear utility experience with cobalt-free hardfacing alloys is described. The use of low-cobalt or cobalt-free alloys in other nuclear plant components is described. 17 figs., 38 tabs., 18 refs. (Author).

Cobalt reduction of NSSS valve hardfacings for ALARA

International Nuclear Information System (INIS)

Kim, Joo Hak; Lee, Sang Sub

1994-07-01

This report informs NSSS designer that replacement of materials is one of the major means of ALARA implementation, and describes that NSSS valves with high-cobalt hardfacing are significant contributors to post-shutdown radiation fields caused by activation of cobalt-59 to cobalt-60. Generic procedures for implementing cobalt reduction programs for valves are presented. Discussions are presented of the general and specific design requirements for valve hardfacing in nuclear service. The nuclear safety issues involved with changing valve hardfacing materials are discussed. The common methods used to deposit hardfacing materials are described together with an explanation of the wear measurements. Wear resistance, corrosion resistance, friction coefficient, and mechanical properties of candidate hardfacing alloys are given. World-wide nuclear utility experience with cobalt-free hardfacing alloys is described. The use of low-cobalt or cobalt-free alloys in other nuclear plant components is described. 17 figs., 38 tabs., 18 refs. (Author)

Waste treatment

International Nuclear Information System (INIS)

Davies, D.; Hooper, E.W.

1981-01-01

In the treatment of wastes, such as liquid radioactive effluents, it is known to remove radionuclides by successive in situ precipitation of cobalt sulphide, an hydroxide, barium sulphate and a transition element ferrocyanide, followed by separation of the thereby decontaminated effluent. In this invention, use is made of precipitates such as obtained above in the treatment of further fresh liquid radioactive effluent, when it is found that the precipitates have additional capacity for extracting radionuclides. The resulting supernatant liquor may then be subjected to a further precipitation treatment such as above. Decontamination factors for radionuclides of Ce, Ru, Sr and Cs have been considerably enhanced. (author)

The Role of External Inputs and Internal Cycling in Shaping the Global Ocean Cobalt Distribution: Insights From the First Cobalt Biogeochemical Model

Science.gov (United States)

Tagliabue, Alessandro; Hawco, Nicholas J.; Bundy, Randelle M.; Landing, William M.; Milne, Angela; Morton, Peter L.; Saito, Mak A.

2018-04-01

Cobalt is an important micronutrient for ocean microbes as it is present in vitamin B12 and is a co-factor in various metalloenzymes that catalyze cellular processes. Moreover, when seawater availability of cobalt is compared to biological demands, cobalt emerges as being depleted in seawater, pointing to a potentially important limiting role. To properly account for the potential biological role for cobalt, there is therefore a need to understand the processes driving the biogeochemical cycling of cobalt and, in particular, the balance between external inputs and internal cycling. To do so, we developed the first cobalt model within a state-of-the-art three-dimensional global ocean biogeochemical model. Overall, our model does a good job in reproducing measurements with a correlation coefficient of >0.7 in the surface and >0.5 at depth. We find that continental margins are the dominant source of cobalt, with a crucial role played by supply under low bottom-water oxygen conditions. The basin-scale distribution of cobalt supplied from margins is facilitated by the activity of manganese-oxidizing bacteria being suppressed under low oxygen and low temperatures, which extends the residence time of cobalt. Overall, we find a residence time of 7 and 250 years in the upper 250 m and global ocean, respectively. Importantly, we find that the dominant internal resupply process switches from regeneration and recycling of particulate cobalt to dissolution of scavenged cobalt between the upper ocean and the ocean interior. Our model highlights key regions of the ocean where biological activity may be most sensitive to cobalt availability.

Radionuclide Generator ^{111}In\\to^{111m}Cd

CERN Document Server

Filossofov, D V; Lebedev, N A; Starodub, G Ya; Novgorodov, A F

2001-01-01

Radionuclide generator ^{111}In\\to^{111m}Cd with chemical yield > 95 % and contamination of the ^{111m}Cd by parent isotope (^{111}In) less than 0.6 % (of ^{111m}Cd activity) is developed. Extraction chromatography with di-2-ethylhexyl-phosphoric acid as an extragent is used for the radiochemical separation of the parent and the daughter radionuclides. Probability of the electron capture on the isomeric level 396 keV (^{111m}Cd) in the ^{111}In decay process is determinated to be (6.01\\pm 0.14_{stat}\\pm0.18_{syst})\\cdot10^{-5}.

Accumulation of cobalt by cephalopods

International Nuclear Information System (INIS)

Nakahara, Motokazu

1981-01-01

Accumulation of cobalt by cephalopod mollusca was investigated by radiotracer experiments and elemental analysis. In the radiotracer experiments, Octopus vulgaris took up cobalt-60 from seawater fairly well and the concentration of the nuclide in whole body attained about 150 times the level of seawater at 25th day at 20 0 C. Among the tissues and organs measured, branchial heart which is the specific organ of cephalopods showed the highest affinity for the nuclide. The organ accumulated about 50% of the radioactivity in whole body in spite of its little mass as 0.2% of total body weight. On the other hand, more than 90% of the radioactivity taken up from food (soft parts of Gomphina melanaegis labelled with cobalt-60 previously in an aquarium) was accumulated in liver at 3rd day after the single administration and then the radioactivity in the liver seemed to be distributed to other organs and tissues. The characteristic elution profiles of cobalt-60 was observed for each of the organs and tissues in Sephadex gel-filtration experiment. It was confirmed by the gel-filtration that most of cobalt-60 in the branchial heart was combined with the constituents of low molecular weights. The average concentration of stable cobalt in muscle of several species of cephalopods was 5.3 +- 3.0 μg/kg wet and it was almost comparable to the fish muscle. On the basis of soft parts, concentration of the nuclide closed association among bivalve, gastropod and cephalopod except squid that gave lower values than the others. (author)

Cobalt-free nickel-base superalloys

International Nuclear Information System (INIS)

Koizumi, Yutaka; Yamazaki, Michio; Harada, Hiroshi

1979-01-01

Cobalt-free nickel-base cast superalloys have been developed. Cobalt is considered to be a beneficial element to strengthen the alloys but should be eliminated in alloys to be used for direct cycle helium turbine driven by helium gas from HTGR (high temp. gas reactor). The elimination of cobalt is required to avoid the formation of radioactive 60 Co from the debris or scales of the alloys. Cobalt-free alloys are also desirable from another viewpoint, i.e. recently the shortage of the element has become a serious problem in industry. Cobalt-free Mar-M200 type alloys modified by the additions of 0.15 - 0.2 wt% B and 1 - 1.5 wt% Hf were found to have a creep rupture strength superior or comparable to that of the original Mar-M200 alloy bearing cobalt. The ductility in tensile test at 800 0 C, as cast or after prolonged heating at 900 0 C (the tensile test was done without removing the surface layer affected by the heating), was also improved by the additions of 0.15 - 0.2% B and 1 - 1.5% Hf. The morphology of grain boundaries became intricated by the additions of 0.15 - 0.2% B and 1 - 1.5% Hf, to such a degree that one can hardly distinguish grain boundaries by microscopes. The change in the grain boundary morphology was considered, as suggested previously by one of the authors (M.Y.), to be the reason for the improvements in the creep rupture strength and tensile ductility. (author)

Acidified seawater increases accumulation of cobalt but not cesium in manila clam Ruditapes philippinarum.

Science.gov (United States)

Sezer, Narin; Kocaoğlan, Hasan Oğuz; Kılıç, Önder; Lacoue-Labarthe, Thomas; Belivermiş, Murat

2018-04-01

The pH of seawater around the world is expected to continue its decline in the near future in response to ocean acidification that is driven by heightened atmospheric CO 2 emissions. Concomitantly, economically-important molluscs that live in coastal waters including estuaries and embayments, may be exposed to a wide assortment of contaminants, including trace metals and radionuclides. Seawater acidification may alter both the chemical speciation of select elements as well as the physiology of organisms, and may thus pose at risk to many shellfish species, including the manila clam Ruditapes philippinarum. The bioconcentration efficiency of two common radionuclides associated with the nuclear fuel cycle, 134 Cs and 57 Co, were investigated by exposing live clams to dissolved 134 Cs and 57 Co at control (pH = 8.1) and two lowered pH (pH = 7.8 and 7.5) levels using controlled aquaria. The uptake and depuration kinetics of the two radionuclides in the whole-body clam were followed for 21 and 35 days, respectively. At steady-state equilibrium, the concentration factor (CF ss ) for 57 Co increased as the pH decreased (i.e. 130 ± 5, 194 ± 6, and 258 ± 10 at pH levels 8.1, 7.8 and 7.5, respectively), whereas the 134 Cs uptake was not influenced by a change in pH conditions. During depuration, the lowest depuration rate constant of 57 Co by the manila clam was observed at the intermediate pH of 7.8. An increase in the accumulation of 57 Co at the intermediate pH value was thought to be caused mainly by the aragonitic shell of the clam, as well as the low salinity and alkalinity of seawater used in the experiment. Considering that accumulation consists of uptake and depuration, among the three pH conditions moderately acidified seawater enhanced most the accumulation of 57 Co. Accumulation of 134 Cs was not strongly influenced by a reduced pH condition, as represented by an analogous uptake constant rate and CF ss in each treatment. Such results suggest that

Distribution of uranium series radionuclides in upland vegetation of northern Saskatchewan

International Nuclear Information System (INIS)

Sheard, J.W.

1986-01-01

Multivariate methods are used to explore patterns of accumulation of radionuclides and stable elements among 10 plant species at four localities in northern Saskatchewan. Principal components analysis and canonical correlation analysis of the radionuclides and stable elements showed that lead-210 and polonium-210 are correlated with crustal elements distributed in the atmoshpere and therefore are accumulated more abundantly by lichen and moss species than by vascular plants. Uranium showed a similar trend. Neither these radionuclides nor radium-226 showed strong correlations with other stable elements. The highest accumulation of uranium was in the Wollaston Lake region, especially for the nonvascular plants, where the soil levels are lowest. This tends to substantiate previous suggestions that uranium available for uptake by vascular plants is associated with groundwater rather than soil particles. Canonical variates analysis on radionuclide levels in vegetation by species group shows that trees, shrubs, lichens, and moss all have significantly different patterns of accumulation. The vascular and nonvascular groups are separated primarily by lead-210 and polonium- 210 accumulation. The trees and shrubs are separated by radium-226 levels. A similar analysis by locality showed significant differences in radionuclide accumulation by vegetation in all possible pairs of localities, except between the two Wollaston Lake localities. The largest distances were between regions and were based primarily on uranium accumulation in the nonvascular plants. Differences in radium-226 levels among the shrub species are responsible for the significant difference between the two localities in the Churchill River region

Mössbauer spectroscopic study of cobalt hexacyanoferrate nanoparticles: Effect of hydrogenation

Science.gov (United States)

Kumar, Asheesh; Kanagare, A. B.; Meena, Sher Singh; Banerjee, S.; Kumar, P.; Sudarsan, V.

2018-04-01

This paper reports Mössbauer study of cobalt hexacyanoferrate (CoHCF) before and after hydrogenation. The CoHCF was synthesised by chemical precipitation method. The sample was characterized by using various techniques (XRD, TG, EDX and FTIR). The CoHCF paricles show fcc structure. The hydrogen storage property was measured at different temperature. The COHCF shows maximum 0.93 wt% hydrogen storage capacity at 223K. 57Fe Mössbauer spectroscopic study shows the effect of hydrogenation on the electronic structure in terms of electronic charge distribution and volume expansion. Isomer shift and quadrupole splitting values were found to be increased after hydrogenation.

Natural radionuclide distribution in phosphate fertilizer and superphosphate production technology

Energy Technology Data Exchange (ETDEWEB)

Lisachenko, Eh P; Ponikarova, T M; Lisitsyna, Yu Z

1987-01-01

The obtained data on the natural radionuclide distribution by phosphate fertilizer and superphosphate production process stages testify to phosphate fertilizer enrichment 2-4 times in relation to initial ore, depending in the raw material used. In this case uranium and thorium series element concentration value (in equilibrium with their decomposition products), proposed as a regulating one in phosphorus-containing fertilizers, is not achieved. However, the fact of lurichment as it is and the enrichment factor, stated in the course of the work, should be taken into account for evaluation of phosphorite new deposit raw material with higher concentrations of natural radionuclides. Natural radionuclide separation in the enrichment process and superphosphate production is not revealed.

Radioprotective effect of microelements at the territories contaminated by radionuclides

International Nuclear Information System (INIS)

Gudkov, I.N.

2007-01-01

The most radioactively contaminated region of Ukrainian and Byelorussian Palesse belongs to a biogeochemical province where soils, plants, and, accordingly, forage for animals and food stuffs are poor with biologically important microelements - iodine, zinc, copper, cobalt, fluorine, manganese, lithium, boron. It is a cause of specific diseases of plants, animals and people known as hypomicroelementhoses. Carrying out the radioprotective measures (countermeasures), particularly liming of soils and applying the heightened doses of phosphoric fertilizers, reduces transfer of radionuclides from soil to plants and also elements of mineral nutrition included the microelements. It aggravates the deficiency of microelements following the decrease of productivity and quality of production in plant and animal breeding and exacerbation of the mentioned diseases. It is known, that many microelements have radioprotective properties, and same of them can influence on uptake of other elements in plants. Therefore, considering the situation with microelements, we can expect of their role in radiation protection of living organisms in a zone affected by accident in Chernobyl NPP. It was shown the applying (root injection) of zinc, manganese, cobalt, copper in the sulfates and chlorides (4-6 kg of metal per hectare) on soddy-podsolic soil, reduced the Sr 90 and Cs 137 transfer factor. Zinc was the most effective: the content of both radionuclides in grain of oats and lupine decreased in 1,5-2 times. Lesser efficiency was observed with manganese and cobalt, much less - with copper. Moreover, in some cases the increase of Sr 90 accumulation was observed. Influence of microelements was stronger in variants without fertilizers, than with their heightened doses. It happened because, firstly, fertilizers contain some various microelements. And, secondly, in favorable conditions for growth and development of plants provided by fertilizers, the action of both factors, positive, and

Cobalt-60 production in CANDU power reactors

International Nuclear Information System (INIS)

Malkoske, G.R.; Norton, J.L.; Slack, J.

2002-01-01

MDS Nordion has been supplying cobalt-60 sources to industry for industrial and medical purposes since 1946. These cobalt-60 sources are used in many market and product segments, but are primarily used to sterilize single-use medical products including; surgical kits, gloves, gowns, drapes, and cotton swabs. Other applications include sanitization of cosmetics, microbial reduction of pharmaceutical raw materials, and food irradiation. The technology for producing the cobalt-60 isotope was developed by MDS Nordion and Atomic Energy of Canada Limited (AECL) almost 55 years ago using research reactors at the AECL Chalk River Laboratories in Ontario, Canada. The first cobalt-60 source produced for medical applications was manufactured by MDS Nordion and used in cancer therapy. The benefits of cobalt-60 as applied to medical product manufacturing, were quickly realized and the demand for this radioisotope quickly grew. The same technology for producing cobalt-60 in research reactors was then designed and packaged such that it could be conveniently transferred to a utility/power reactor. In the early 1970's, in co-operation with Ontario Power Generation (formerly Ontario Hydro), bulk cobalt-60 production for industrial irradiation applications was initiated in the four Pickering A CANDU reactors. As the demand and acceptance of sterilization of medical products grew, MDS Nordion expanded its bulk supply by installing the proprietary Canadian technology for producing cobalt-60 in additional CANDU reactors. CANDU is unique among the power reactors of the world, being heavy water moderated and fuelled with natural uranium. They are also designed and supplied with stainless steel adjusters, the primary function of which is to shape the neutron flux to optimize reactor power and fuel bum-up, and to provide excess reactivity needed to overcome xenon-135 poisoning following a reduction of power. The reactor is designed to develop full power output with all of the adjuster

Project 57 Air Monitoring Report: October 1, 2013, through December 31, 2014

Energy Technology Data Exchange (ETDEWEB)

Mizell, Steve A. [Desert Research Inst. (DRI), Las Vegas, NV (United States); Nikolich, George [Desert Research Inst. (DRI), Las Vegas, NV (United States); McCurdy, Greg [Desert Research Inst. (DRI), Reno, NV (United States); Shadel, Craig [Desert Research Inst. (DRI), Las Vegas, NV (United States); Miller, Julianne J. [Desert Research Inst. (DRI), Las Vegas, NV (United States)

2016-02-01

On April 24, 1957, the Atomic Energy Commission (AEC, now the Department of Energy [DOE]) conducted the Project 57 safety experiment in western Emigrant Valley north east of the Nevada National Security Site (NNSS, formerly the Nevada Test Site) on lands withdrawn by the Department of Defense (DoD) for the Nevada Test and Training Range (NTTR). The test was undertaken to develop (1) a means of estimating plutonium distribution resulting from a nonnuclear detonation; (2) biomedical evaluation techniques for use in plutonium-laden environments; (3) methods of surface decontamination; and (4) instruments and field procedures for prompt estimation of alpha contamination (Shreve, 1958). Although the test did not result in the fission of nuclear materials, it did disseminate plutonium across the land surface. Following the experiment, the AEC fenced the contaminated area and returned control of the surrounding land to the DoD. Various radiological surveys have been performed in the area and in 2007, the DOE expanded the demarked contamination area by posting signs 200 to 400 feet (60 to 120 meters) outside of the original fence. Plutonium in soil is thought to attach preferentially to smaller particles. Therefore, redistribution of soil particulates by wind (dust) is the mechanism most likely to transport plutonium beyond the boundary of the Project 57 contamination area. In 2011, DRI installed two instrumentation towers to measure radiological, meteorological, and dust conditions. The monitoring activity was implemented to determine if radionuclide contamination was detectable in samples of airborne dust and characterize meteorological and environmental parameters that influence dust transport. Collected data also permits comparison of radiological conditions at the Project 57 monitoring stations to conditions observed at Community Environmental Monitoring Program (CEMP) stations around the NTTR. Biweekly samples of airborne particulates are submitted for laboratory

Experimental evidence for cobalt(III)-carbene radicals: key intermediates in cobalt(II)-based metalloradical cyclopropanation

NARCIS (Netherlands)

Lu, H.; Dzik, W.I.; Xu, X.; Wojtas, L.; de Bruin, B.; Zhang, X.P.

2011-01-01

New and conclusive evidence has been obtained for the existence of cobalt(III)-carbene radicals that have been previously proposed as the key intermediates in the underlying mechanism of metalloradical cyclopropanation by cobalt(II) complexes of porphyrins. In the absence of olefin substrates,

Palladium-cobalt particles as oxygen-reduction electrocatalysts

Science.gov (United States)

Adzic, Radoslav [East Setauket, NY; Huang, Tao [Manorville, NY

2009-12-15

The present invention relates to palladium-cobalt particles useful as oxygen-reducing electrocatalysts. The invention also relates to oxygen-reducing cathodes and fuel cells containing these palladium-cobalt particles. The invention additionally relates to methods for the production of electrical energy by using the palladium-cobalt particles of the invention.

Removal of Cobalt Ions by Precipitate Foam Flotation

Energy Technology Data Exchange (ETDEWEB)

Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

1998-09-30

Simulated waste liquid containing 50 ppm cobalt ion was tested by precipitate flotation using a sodium lauryl sulfate as a collector. The effects of initial cobalt ion concentration, pH, surfactant concentration, flotation time, gas flow rate and foreign ions on removal efficiency of cobalt ion were studied. Pretreatment of the waste liquid with 35% H{sub 2}O{sub 2} prior to precipitate flotation made shift of optimal flotation pH from the strong alkalinity to weak alkaline range and made a favorable flotation of cobalt ion in wide range of pH. For the result of this experiment, 99.8% removal efficiency was obtained on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, flotation time 30 min. The simulate ion was formed to be the most harmful ion against removal of cobalt by precipitate flotation of the species which were tested. The presence of 0.1 M of SO{sub 4}{sup 2-} ion decreased removal efficiency of cobalt to 90% while the cobalt were almost entirely removed in the absence of sulfate ion. (author). 11 refs., 8 figs.

Nuclear Wastes: Technologies for Separations and Transmutation

National Research Council Canada - National Science Library

.... The committee examines the currently used "once-through" fuel cycle versus different alternatives of separations and transmutation technology systems, by which hazardous radionuclides are converted...

Natural radionuclides in Italian diet and their annual intake

International Nuclear Information System (INIS)

Donatella Desideri; Maria Assunta Meli; Carla Roselli; Laura Feduzi; Nevio Forini; Alba Rongoni

2014-01-01

This study was dedicated to the evaluation of the background activity concentration of natural radionuclides as 228 Ra and 228 Th of 232 Th family, 226 Ra of 238 U family and 40 K in the Italian daily diet. These radionuclides were determined by gamma spectrometry. 40 K activity concentration, in the samples taken into account in the present paper, ranged between 70.5 (milk) and 181.1 Bq kg ww -1 (pasta), 226 Ra activity concentration ranged between 1.1 (milk) and 5.7 Bq kg ww -1 (pasta), 228 Ra and 228 Th activity concentration, in the same samples, ranged between 0.7 (milk) and 3.7 Bq kg ww -1 (pasta) and between 1.4 (milk) and 6.1 Bq kg ww -1 (flours) respectively. The annual intake of every radionuclide from foodstuffs ingestion was also calculated. The 94-95 % of the total intake comes from 40 K. For adults and children, the highest activity intake of all radioisotopes was from grain products, for infants it was from milk products. (author)

Cobalt: for strength and color

Science.gov (United States)

Boland, Maeve A.; Kropschot, S.J.

2011-01-01

Cobalt is a shiny, gray, brittle metal that is best known for creating an intense blue color in glass and paints. It is frequently used in the manufacture of rechargeable batteries and to create alloys that maintain their strength at high temperatures. It is also one of the essential trace elements (or "micronutrients") that humans and many other living creatures require for good health. Cobalt is an important component in many aerospace, defense, and medical applications and is a key element in many clean energy technologies. The name cobalt comes from the German word kobold, meaning goblin. It was given this name by medieval miners who believed that troublesome goblins replaced the valuable metals in their ore with a substance that emitted poisonous fumes when smelted. The Swedish chemist Georg Brandt isolated metallic cobalt-the first new metal to be discovered since ancient times-in about 1735 and identified some of its valuable properties.

Complex magnetic differentiation of cobalts in Na x CoO2 with 22 K Néel temperature

Science.gov (United States)

Mukhamedshin, I. R.; Gilmutdinov, I. F.; Salosin, M. A.; Alloul, H.

2014-06-01

Single crystals of sodium cobaltates Na x CoO2 with x ≈ 0.8 were grown by the floating zone technique. Using electrochemical Na de-intercalation method we reduced the sodium content in the as-grown crystals down to pure phase with 22 K Néel temperature and x ≈ 0.77. The 59Co NMR study in the paramagnetic state of the T N = 22 K phase permitted us to evidence that at least 6 Co sites are differentiated. They could be separated by their magnetic behavior into three types: a single site with cobalt close to non-magnetic Co3+, two sites with the most magnetic cobalts in the system, and the remaining three sites displaying an intermediate behavior. This unusual magnetic differentiation calls for more detailed NMR experiments on our well characterized samples.

Influence of natural organic matter on the speciation of radionuclides in a geochemistry context

International Nuclear Information System (INIS)

Marang, L.

2007-09-01

The principal aim of this work is the study of the influence of natural organic matter, in particularly humic substances (HS), on the speciation of radionuclides (RN). The studied radionuclides are cobalt (II), europium (III) and uranium (VI). It has been shown that mobility and bioavailability of a metal are related to its speciation. The NICA-Donnan model describes metal ion binding to NOM: it accounts for NOM chemical heterogeneity, competition during binding and ionic strength effects. However the model has been calibrated with a limited number of experimental data for the RN. Indeed there is only a few speciation technique available for the study of the interactions RN-HS. Within the framework of this study, we have developed and optimised speciation technique (Flux Donnan Membrane Technique and the use of an un-solubilized humic acid) in order to acquire new experimental data, we have also studied the effect of the competition on RN speciation and finally we have tested the model capacity to predict the RN behavior in laboratory or in situ. (author)

Influence of natural organic matter on the speciation of radionuclides in a geochemistry context

International Nuclear Information System (INIS)

Marang, L.

2007-09-01

The principal aim of this work is the study of the influence of natural organic matter, in particularly humic substances (HS), on the speciation of radionuclides (RN). The studied radionuclides are cobalt (II), europium (III) and uranium (VI). It has been shown that mobility and bioavailability of a metal are related to its speciation. The NICA-Donnan model describes metal ion binding to NOM: it accounts for NOM chemical heterogeneity, competition during binding and ionic strength effects. However the model has been calibrated with a limited number of experimental data for the RN. Indeed there is only a few speciation techniques available for the study of the interactions RN-HS. Within the framework of this study, we have developed and optimised speciation technique (Flux Donnan Membrane Technique and the use of an insolubilized humic acid) in order to acquire new experimental data, we have also studied the effect of the competition on RN speciation and finally we have tested the model capacity to predict the RN behavior in laboratory or in situ. (author)

Short-lived radionuclides produced on the ORNL 86-inch cyclotron and High-Flux Isotope Reactor

International Nuclear Information System (INIS)

Lamb, E.

1985-01-01

The production of short-lived radionuclides at ORNL includes the preparation of target materials, irradiation on the 86-in. cyclotron and in the High Flux Isotope Reactor (HFIR), and chemical processing to recover and purify the product radionuclides. In some cases the target materials are highly enriched stable isotopes separated on the ORNL calutrons. High-purity 123 I has been produced on the 86-in. cyclotron by irradiating an enriched target of 123 Te in a proton beam. Research on calutron separations has led to a 123 Te product with lower concentrations of 124 Te and 126 Te and, consequently to lower concentrations of the unwanted radionuclides, 124 I and 126 I, in the 123 I product. The 86-in. cyclotron accelerates a beam of protons only but is unique in providing the highest available beam current of 1500 μA at 21 MeV. This beam current produces relatively large quantities of radionuclides such as 123 I and 67 Ga

Radionuclide toxicity

International Nuclear Information System (INIS)

Galle, P.

1982-01-01

The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

Speciation Analysis of Radionuclides in the Environment - NSK-B SPECIATION project report 2009

DEFF Research Database (Denmark)

Hou, Xiaolin; Aldahan, Ala; Possnert, Göran

. Speciation of radionuclides in soils and sediments includes: Sequential extraction of radionuclides in sediments and of trace elements in soil samples. Sequential extraction of radionuclides in aerosols and particles has also been performed. Further-more, sorption experiments have been performed......, sediments, particles); and (3) Intercomparison excise for speciation analysis of radionu-clides in soil and sediment. This report summarizes the work completed in the project partners’ laboratories, Method developments include: Development of an rapid and in-suit separation method for the speciation...... analysis of 129I in seawater samples; Development of a simple method for the speciation analysis of 129I in fresh water and seawater samples; Development of an on-line HPLC-ICP-MS method for the direct speciation analysis of 127I in water and leachate samples; Speciation of radionuclides in water includes...

Effects of cobalt in nickel-base superalloys

Science.gov (United States)

Tien, J. K.; Jarrett, R. N.

1983-01-01

The role of cobalt in a representative wrought nickel-base superalloy was determined. The results show cobalt affecting the solubility of elements in the gamma matrix, resulting in enhanced gamma' volume fraction, in the stabilization of MC-type carbides, and in the stabilization of sigma phase. In the particular alloy studied, these microstructural and microchemistry changes are insufficient in extent to impact on tensile strength, yield strength, and in the ductilities. Depending on the heat treatment, creep and stress rupture resistance can be cobalt sensitive. In the coarse grain, fully solutioned and aged condition, all of the alloy's 17% cobalt can be replaced by nickel without deleteriously affecting this resistance. In the fine grain, partially solutioned and aged condition, this resistance is deleteriously affected only when one-half or more of the initial cobalt content is removed. The structure and property results are discussed with respect to existing theories and with respect to other recent and earlier findings on the impact of cobalt, if any, on the performance of nickel-base superalloys.

Cobalt: A vital element in the aircraft engine industry

Science.gov (United States)

Stephens, J. R.

1981-01-01

Recent trends in the United States consumption of cobalt indicate that superalloys for aircraft engine manufacture require increasing amounts of this strategic element. Superalloys consume a lion's share of total U.S. cobalt usage which was about 16 million pounds in 1980. In excess of 90 percent of the cobalt used in this country was imported, principally from the African countries of Zaire and Zambia. Early studies on the roles of cobalt as an alloying element in high temperature alloys concentrated on the simple Ni-Cr and Nimonic alloy series. The role of cobalt in current complex nickel base superalloys is not well defined and indeed, the need for the high concentration of cobalt in widely used nickel base superalloys is not firmly established. The current cobalt situation is reviewed as it applies to superalloys and the opportunities for research to reduce the consumption of cobalt in the aircraft engine industry are described.

Recovery and Separation of Valuable Metals from Spent Nickel-Metal Hydride Batteries using some Organophosphorus Extractants

International Nuclear Information System (INIS)

Aly, M.I.; Daoud, J.A.; ALy, H.F.

2012-01-01

The separation of cobalt, nickel, and rare earth elements from NiMH battery residues is evaluated in this paper. A hydrometallurgical process is developed for the recovery of metals from spent batteries and a selective separation of RE by precipitation of sodium RE double sulfate is performed. The methodology used benefits the solubility of the battery electrode materials in sulfuric or hydrochloric acids. The results obtained show that sulfuric acid is slightly less powerful in leaching (NiMH) compared to HCl acid. However, sulfuric acid was used on economic basis. Leaching solution was obtained by using 3 M H 2 SO 4 at 70 +1 degree C + 3% wt. H 2 O 2 for 5 hours. It has been shown that it is possible to recover about 98 % of the RE contained in spent NiMH batteries. The maximum recovery of nickel and cobalt metals was 99.9% and 99.4%, respectively. The effects of the main operating variables of both leaching and solvent extraction steps of nickel (II) and cobalt (II) from the leach solution using HDEHP (di-2-ethylhexyl phosphoric acid) and CYANEX 272 (di-(2,4,4 trimethyl pentyl) phosphinic acid) in kerosene were investigated aiming to maximize metal separation for recycling purposes. The developed process for the recovery and separation of nickel (II) , cobalt (II), and rare earth from spent NiMH batteries is tested and the obtained sulfate salts CoSO 4 and NiSO 4 have a high purity, suggesting that these recovered products could be used as chemical materials without further purification

Feasibility Study for Cobalt Bundle Loading to CANDU Reactor Core

International Nuclear Information System (INIS)

Park, Donghwan; Kim, Youngae; Kim, Sungmin

2016-01-01

CANDU units are generally used to produce cobalt-60 at Bruce and Point Lepreau in Canada and Embalse in Argentina. China has started production of cobalt-60 using its CANDU 6 Qinshan Phase III nuclear power plant in 2009. For cobalt-60 production, the reactor’s full complement of stainless steel adjusters is replaced with neutronically equivalent cobalt-59 adjusters, which are essentially invisible to reactor operation. With its very high neutron flux and optimized fuel burn-up, the CANDU has a very high cobalt-60 production rate in a relatively short time. This makes CANDU an excellent vehicle for bulk cobalt-60 production. Several studies have been performed to produce cobalt-60 using adjuster rod at Wolsong nuclear power plant. This study proposed new concept for producing cobalt-60 and performed the feasibility study. Bundle typed cobalt loading concept is proposed and evaluated the feasibility to fuel management without physics and system design change. The requirement to load cobalt bundle to the core was considered and several channels are nominated. The production of cobalt-60 source is very depend on the flux level and burnup directly. But the neutron absorption characteristic of cobalt bundle is too high, so optimizing design study is needed in the future

Feasibility Study for Cobalt Bundle Loading to CANDU Reactor Core

Energy Technology Data Exchange (ETDEWEB)

Park, Donghwan; Kim, Youngae; Kim, Sungmin [KHNP Central Research Institute, Daejeon (Korea, Republic of)

2016-10-15

CANDU units are generally used to produce cobalt-60 at Bruce and Point Lepreau in Canada and Embalse in Argentina. China has started production of cobalt-60 using its CANDU 6 Qinshan Phase III nuclear power plant in 2009. For cobalt-60 production, the reactor’s full complement of stainless steel adjusters is replaced with neutronically equivalent cobalt-59 adjusters, which are essentially invisible to reactor operation. With its very high neutron flux and optimized fuel burn-up, the CANDU has a very high cobalt-60 production rate in a relatively short time. This makes CANDU an excellent vehicle for bulk cobalt-60 production. Several studies have been performed to produce cobalt-60 using adjuster rod at Wolsong nuclear power plant. This study proposed new concept for producing cobalt-60 and performed the feasibility study. Bundle typed cobalt loading concept is proposed and evaluated the feasibility to fuel management without physics and system design change. The requirement to load cobalt bundle to the core was considered and several channels are nominated. The production of cobalt-60 source is very depend on the flux level and burnup directly. But the neutron absorption characteristic of cobalt bundle is too high, so optimizing design study is needed in the future.

Nickel, cobalt, and their alloys

CERN Document Server

2000-01-01

This book is a comprehensive guide to the compositions, properties, processing, performance, and applications of nickel, cobalt, and their alloys. It includes all of the essential information contained in the ASM Handbook series, as well as new or updated coverage in many areas in the nickel, cobalt, and related industries.

Cobalt sorption onto Savannah River Plant soils

International Nuclear Information System (INIS)

Hoeffner, S.L.

1985-06-01

A laboratory study of cobalt-60 sorption was conducted using Savannah River Plant soil and groundwater from the low-level waste burial ground. Systematic variation of soil and water composition indicates that cobalt sorption is most strongly a function of pH. Over a pH range of 2 to 9, the distribution coefficient ranged from 2 to more than 10,000 mL/g. Changes in clay content and in K + , Ca 2+ , or Mg 2+ concentrations influence cobalt sorption indirectly through the slight pH changes which result. The ions Na + , Cl - , and NO 3 - have no effect on cobalt sorption. Ferrous ion, added to groundwater to simulate the condition of water at the bottom of the waste trenches, accounts for part of the decrease in cobalt sorption observed with trench waters. 17 refs., 3 figs., 4 tabs

Manipulating radicals: Using cobalt to steer radical reactions

OpenAIRE

Chirilă, A.

2017-01-01

This thesis describes research aimed at understanding and exploiting metallo-radical reactivity and explores reactions mediated by square planar, low-spin cobalt(II) complexes. A primary goal was to uncover novel reactivity of discrete cobalt(III)-bound carbene radicals generated upon reaction of the cobalt(II) catalysts with carbene precursors. Another important goal was to replace cobalt(II)-porphyrin catalysts with cheaper and easier to prepare metallo-radical analogues. Therefore the cata...

Production cross-sections of radionuclides from α-induced reactions on natural copper up to 50 MeV

International Nuclear Information System (INIS)

Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Murakami, Masashi; Komori, Yukiko

2016-01-01

The excitation functions were measured for the "n"a"tCu(α,x)"6"6","6"7Ga,"6"5Zn,"5"7","5"8","6"0Co reactions in the energy range of 16.5 −50 MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications. - Highlights: • New measurements of gallium radionuclides for monitor reactions. • Production of cobalt radionuclides via alpha route on natural Copper. • Extensive critical review of earlier reported cross-sections.

The separation and determination of trace elements in iron ore

International Nuclear Information System (INIS)

Jones, E.A.

1977-01-01

The separation, concentration, and determination of trace elements in iron ores are described. After the sample has been dissolved, the iron is separated by liquid-liquid extraction with a liquid cation-exchanger, di-(2-ethylhexyl) phosphoric acid. The trace elements aluminium, cadmium, calcium, chromium, cobalt, copper, lead, magnesium, manganese, mercury, potassium, sodium, vanadium, and zinc are determined in the aqueous phase by atomic-absorption spectrophotometry

Radionuclides and heavy metal uptake by lolium italicum plant as affected by saline water irrigation

International Nuclear Information System (INIS)

Ramadan, A.A.; Aly, A.I.; Helal, M.H.

2001-01-01

The use of saline waters to grow crops on increasingly metal polluted soils is becoming a common practice in the arid regions. Nevertheless, the effects of soil and water salinity on radionuclides and heavy metal fluxes in polluted areas are not well understood. The aim of this study was to evaluate in pot experiments the plant uptake of cesium-137, Co-60, Mn-54, Zinc, cadmium and copper from a polluted alluvial aridisol as affected by salt water irrigation. Fertilized soil material was planted in pots with L. Italicum for 18 weeks under greenhouse conditions. The plants were irrigated either with water or with salt solution of variable variable Na/Ca ratio and harvested every 5-7 weeks. In addition to elemental analysis of plants and soil extracts root length was determined by a gridline intersect method and the viable part of the roots was estimated by a root protein inex. Saline (Na) water irrigation increased cobalt-60, manganese-54 and heavy metal solubility in soil, reduced root viability and enhanced the uptake of Co-60, Mn-54, Cd, Cu, Zn and Na by L.italicum and reduced the uptake of Cs-137. Ca counteracted these effects partly. The presented results demonstrated a dual effect of salinity on radiouclides and heavy metal availability to plants and suggest a relationship between root mortality and the enhanced Co-60, Mn-54, and heavy metake ny salt stressed plants

Radionuclide migration in fractured rock: hydrological investigations at an experimental site in the Carnmennellis granite, Cornwall

International Nuclear Information System (INIS)

Heath, M.J.; Durrance, E.M.

1985-01-01

The objectives, methods and results of hydrological investigation of the granite at an experimental site in Cornwall are described and discussed. Constant head injection tests and radioactive tracer experiments have revealed a fracture permeability in which water movement is confined to discrete fractures separated by rock of very low permeability. Data on flow path frequency, orientation and effective hydraulic aperture, required for network modelling, are presented for a 700 m borehole, with additional hydraulic data from three other boreholes. In addition to fractures of average hydraulic conductivity a small number of major hydraulic features (''main drains'') with major implications for radionuclide migration have been identified. A mean hydraulic conductivity for the granite investigated of 1.57x10 -7 ms -1 has been obtained, 2.11x10 -8 ms -1 if the major hydraulic features are excluded

Transport of cobalt-60 industrial radiation sources

Science.gov (United States)

Kunstadt, Peter; Gibson, Wayne

This paper will deal with safety aspects of the handling of Cobalt-60, the most widely used industrial radio-isotope. Cobalt-60 is a man-made radioisotope of Cobalt-59, a naturally occurring non radioactive element, that is made to order for radiation therapy and a wide range of industrial processing applications including sterilization of medical disposables, food irradiation, etc.

Daily intakes of radionuclides in Japanese standard diets

International Nuclear Information System (INIS)

Terada, H.; Sugiyama, H.; Iijima, I.; Isomura, K.; Kobayashi, J.

2005-01-01

Daily intakes of radionuclides in Japanese standard diets were investigated. Food samples were collected from 9 cities of Japan using the market basket method according to the reports of National Nutrition Study in Japan (2000). These samples were categorized the following 14 groups; Group l: rice, rice products; Group 2: grain, seeds, potato; Group 3: sugar, confectionery; Group 4: oils and fats; Group 5: beans; Group 6: fruits; Group 7: green and yellow vegetables; Group 8: other vegetables; mushrooms, seaweed; Group 9: seasoning, drinks; Group 10: fish and shellfish; Group 11: meat, eggs; Group 12: milk, milk products; Group 13: other foods; and Group 14 was drinking water. Each group was homogenized separately after cooking the food materials. Determination of radioactivity was performed by gamma ray spectrometry. The only artificial radionuclide detected from gamma ray spectrometry was 137 CS, and its concentrations of each sample were almost less than 0.1 Bq/kg. Strontium-90 and 238 U concentrations of the total diet samples were analyzed with chemical separation. The concentrations of 90 Sr and 238 U were in the range of 0.013-0.031 Bq/kg, 0.0039-0.014 Bq/kg respectively, and a large difference was not found among the concentrations of each nuclide in 9 cities. We would like to estimate internal radiation dose to Japanese population from the dietary intakes of these radionuclides.

Handbook of parameter values for the prediction of radionuclide transfer in temperate environments

International Nuclear Information System (INIS)

1994-01-01

This Handbook has been prepared in response to a widely expressed interest in having a convenient and authoritative reference for radionuclide transfer parameter values used in biospheric assessment models. It draws on data from North America and Europe, much of which was collected through projects of the International Union of Radioecologists (IUR) and the Commission of European Communities (CEC) over the last decade. It is intended to supplement existing IAEA publications on environmental assessment methodology, primarily Generic Models and Parameters for Assessing the Environmental Transfer of Radionuclides from Routine Releases, IAEA Safety Series No. 57 (1982). 219 refs, 3 figs, 32 tabs

Determination of radionuclides present in the relation of waste plant storage of El Cabril

International Nuclear Information System (INIS)

Suarez, J.A.; Rodriguez Alcala, M.; Estartero, A.G.; Pina, G.; Gascon, J.L.

1997-03-01

Different waste streams of low and medium level radioactive are generated from the operation of Nuclear Power Plants with light water reactors. The most important waste streams are: spent ion exchange resin, used to purify the water of the reactor coolant and the evaporator concentrates produced in the evaporation of some liquid radioactive waste. In this paper are show the improvement and development of the analytical methods of all these radionuclides, performed in the CIEMAT project about Characterization of Radioactive Wastes and Materials. The alpha, beta and low energy gamma-emitting radionuclides are analyzed after the separation procedure by alpha-spectrometry, liquid scintillation counting and low-energy gamma spectrometry. The high energy gamma-emitting radionuclides (>50 keV) are analyzed by gamma spectrometry without separation. This work has been developed within the framework of the CIEMAT-ENRESA Association Agreement. (Author) 12 refs

The physiological effect of cobalt on watermelon cultivation

International Nuclear Information System (INIS)

Yao Naihua; Jin Yafang; Sun Yaochen; Huang Yiming

1993-01-01

Cobalt has essential physiological action on both animals and plants. For the latter it can raise plant's nitrogen-fixing ability and saccharine content. Spray of cobalt mixed with other nutritive elements can improve the germinatit of seeds and the yield of fruit. For specifying the nutritive function of cobalt upon watermelon, isotope 60 Co was mixed into a complex leaf nutritive aqua and the regularity of transferring and absorbing cobalt in the watermelon's body was investigated

Relaxation resistance of heat resisting alloys with cobalt

International Nuclear Information System (INIS)

Borzdyka, A.M.

1977-01-01

Relaxation resistance of refractory nickel-chromium alloys containing 5 to 14 % cobalt is under study. The tests involve the use of circular samples at 800 deg to 850 deg C. It is shown that an alloy containing 14% cobalt possesses the best relaxation resistance exceeding that of nickel-chromium alloys without any cobalt by a factor of 1.5 to 2. The relaxation resistance of an alloy with 5% cobalt can be increased by hardening at repeated loading

Developing role of short-lived radionuclides in nuclear medical practice. DOE symposium series; 56

International Nuclear Information System (INIS)

Paras, P.; Thiessen, J.W.

1985-01-01

The purpose was to define the developing role and state-of-the-art development of short-lived radionuclides (SLR's) in current nuclear medical practice. Special emphasis was placed on radionuclides with general-purpose labeling capabilities. The need for high-purity labeling-grade iodine-123 was emphasized in the program. Papers have been separately abstracted for the data base

Heating-induced inner-sphere substitution and reduction-oxidation reactions of the solid phenanthroline containing cobalt (2) and cobalt (3) complexes

International Nuclear Information System (INIS)

Palade, D.M.

1996-01-01

The results of the differential thermal and thermogravimetric analyses of solid phenanthroline-containing complexes of cobalt (2) and cobalt (3) in the atmosphere of the air have been analyzed. Mechanism of redox reactions occurring when cobalt (3) complexes are heated has been discussed. It is shown that some of gaseous products of the redox processes appear as a result of secondary reactions and not the processes of the ligands oxidation by Co 3+ . The influence of certain inner-sphere and coordinated anions (of I, inclusively) on cobalt (3) complexes behaviour during heating has been considered

Control of carbon nanotube growth using cobalt nanoparticles as catalyst

International Nuclear Information System (INIS)

Huh, Yoon; Green, Malcolm L.H.; Kim, Young Heon; Lee, Jeong Yong; Lee, Cheol Jin

2005-01-01

We have controllably grown carbon nanotubes using uniformly distributed cobalt nanoparticles as catalyst. Cobalt nanoparticles with a uniform size were synthesized by chemical reaction and colloidal solutions including the cobalt nanoparticles were prepared. The cobalt nanoparticles were uniformly distributed on silicon substrates by a spin-coating method. Carbon nanotubes with a uniform diameter were synthesized on the cobalt nanoparticles by thermal chemical vapor deposition of acetylene gas. The density and vertical alignment of carbon nanotubes could be controlled by adjusting the density of cobalt (Co) nanoparticles

Influence of speciation on the geospheric migration of radionuclides

International Nuclear Information System (INIS)

Hadermann, J.; Schweingruber, M.

1982-01-01

For geosphere transport calculations in safety analyses of waste repositories it is generally assumed that the retardation of a migrating radionuclide is characterized by a single retention factor. However, in groundwater, radionuclides exist in various chemical forms with strongly differing sorption properties. We consider the effect of pseudo first order chemical reactions in liquid phase on migration. Conditions are derived under which local equilibrium in liquid phase is well fulfilled and migration is governed by a single effective retention factor. It is argued that in geosphere transport, equilibrium is likely to exist even when laboratory measurements show chromatographic separations. (author)

Multitracer study on absorption of radionuclides in atmosphere-plant system

International Nuclear Information System (INIS)

Ambe, Shizuko; Shinonaga, Taeko; Watanabe, Tadakazu; Yamaguchi, Isamu

1996-01-01

Direct absorption of atmospheric radionuclides by soybean plants was studied using a radioactive multitracer consisting of radionuclides of Sc, Mn, Co, As, Se, Rb, Sr, Y, Eu, Gd, Yb, Hf, Re, and Ir. Soybean seedlings were cultivated at 23degC in a box where multitracer-adsorbed cellulose powders were floating in air. After 28-49 day-cultivation, the plants were harvested and divided into beans (seeds and pods), leaves, stems (inside and outside), and roots. Beans or leaves originating from the same node were collected together. After washing with dilute HCl solution and distilled water, they were dried and then subjected to γ-ray measurement. It was estimated that about 0.2 % of the multitracer was absorbed by the soybean plant, of which 80 % was found in the leaves, and 10 % each in beans and stems. The relative amounts of elements in the beans, leaves, and stems markedly differed depending on the element. Among the elements, Se * was greatly accumulated in the beans, leaves, and stems. Cobalt * , Se * , and Rb * were dominant in the beans, especially in the edible part of seeds. Relative amounts of Mn * , As * , Sr * , and Re * in the seeds were very small. It is noticeable that these nuclides were found in the seeds, though they were not physically exposed to the multitracer-adsorbed cellulose powders during growth. The radioactivities of Sc * , Mn * , Co * , As * , Se * , Rb * , Sr * , Y * , Eu * , Gd * , Yb * , Hf * , Re * , and Ir * were observed for the leaves. Brown leaves accumulated greater amounts of radionuclides than green ones. Main nuclides found in the stem were Sc * , Co * , Se * , Y * , Eu * , Gd * , Yb * , Hf * , and Ir * , a larger part of them on the outside. Trace amounts of Co * , Se * , and Rb * were detected in the roots. Little leakage of the multitracer into the soil was observed. These results indicate that various radionuclides in the atmosphere were directly absorbed through soybean leaves and then transported to the edible part

Recovery of lithium and cobalt from waste lithium ion batteries of mobile phone.

Science.gov (United States)

Jha, Manis Kumar; Kumari, Anjan; Jha, Amrita Kumari; Kumar, Vinay; Hait, Jhumki; Pandey, Banshi Dhar

2013-09-01

In view of the stringent environmental regulations, availability of limited natural resources and ever increasing need of alternative energy critical elements, an environmental eco-friendly leaching process is reported for the recovery of lithium and cobalt from the cathode active materials of spent lithium-ion batteries of mobile phones. The experiments were carried out to optimize the process parameters for the recovery of lithium and cobalt by varying the concentration of leachant, pulp density, reductant volume and temperature. Leaching with 2M sulfuric acid with the addition of 5% H(2)O(2) (v/v) at a pulp density of 100 g/L and 75°C resulted in the recovery of 99.1% lithium and 70.0% cobalt in 60 min. H(2)O(2) in sulfuric acid solution acts as an effective reducing agent, which enhance the percentage leaching of metals. Leaching kinetics of lithium in sulfuric acid fitted well to the chemical controlled reaction model i.e. 1-(1-X)(1/3)=k(c)t. Leaching kinetics of cobalt fitted well to the model 'ash diffusion control dense constant sizes spherical particles' i.e. 1-3(1-X)(2/3)+2(1-X)=k(c)t. Metals could subsequently be separated selectively from the leach liquor by solvent extraction process to produce their salts by crystallization process from the purified solution. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dosing of anaerobic granular sludge bioreactors with cobalt: Impact of cobalt retention on methanogenic activity

KAUST Repository

Fermoso, Fernando G.

2010-12-01

The effect of dosing a metal limited anaerobic sludge blanket (UASB) reactor with a metal pulse on the methanogenic activity of granular sludge has thus far not been successfully modeled. The prediction of this effect is crucial in order to optimize the strategy for metal dosage and to prevent unnecessary losses of resources. This paper describes the relation between the initial immobilization of cobalt in anaerobic granular sludge cobalt dosage into the reactor and the evolution of methanogenic activity during the subsequent weeks. An operationally defined parameter (A0· B0) was found to combine the amount of cobalt immobilized instantaneously upon the pulse (B0) and the amount of cobalt immobilized within the subsequent 24. h (A0). In contrast with the individual parameters A0 and B0, the parameter A0· B0 correlated significantly with the methanogenic activity of the sludge during the subsequent 16 or 35. days. This correlation between metal retention and activity evolution is a useful tool to implement trace metal dosing strategies for biofilm-based biotechnological processes. © 2010.

Radionuclide distributions and migration mechanisms at shallow land burial sites. Annual report of research investigations on the distribution, migration and containment of radionuclides at Maxey Flats, Kentucky

International Nuclear Information System (INIS)

Kirby, L.J.

1982-07-01

Subsurface waters at Maxey Flats are anoxic systems with high alkalinity and high concentrations of dissolved ferrous ion. Americium and cobalt in these trench waters are made more soluble by the presence of EDTA, while strontium and cesium are unaffected under the same conditions. EDTA is the major organic complexing component in waste trench 27 leachate, but other polar, water-soluble organics are also present. Evidence points to the migration of plutonium between waste trench 27 and inert atmosphere wells as an EDTA complex. Polar organic compounds may influence the migration of 90 Sr and 137 Cs. The primary pathway of water entry into the waste burial trenches is through the trench caps, but major increases in water level have occurred in an experimental trench by subsurface flow. The areal distribution of radionuclides at Maxey Flats has been influenced by surface runoff, deposition from the evaporator plume, subsurface flow and the actions of burrowing animals or deep-rooted trees. Vegetal and surface contamination on site and near site are quite low, and only 60 Co exceeds commonly observed fallout levels. Radionuclide concentrations in surface soil at Maxey Flats are comparable to concentrations resulting from normal fallout in other areas of high rainfall

Cobalt(II) and Cobalt(III) Coordination Compounds.

Science.gov (United States)

Thomas, Nicholas C.; And Others

1989-01-01

Presents a laboratory experiment which illustrates the formation of tris(phenanthroline)cobalt complexes in the 2+ and 3+ oxidation states, the effect of coordination on reactions of the ligand, and the use of a ligand displacement reaction in recovering the transformed ligand. Uses IR, UV-VIS, conductivity, and NMR. (MVL)

Influence of the composition of radionuclide mixtures on the maximum permissible concentration

International Nuclear Information System (INIS)

Schillinger, K.; Schuricht, V.

1975-08-01

By dividing radionuclides according to their formation mechanisms it is possible to assess the influence of separate partial mixtures on the maximum permissible concentration (MPC) of the total mixture without knowing exactly their contribution to the total activity. Calculations showed that the MPC of a total mixture of unsoluble radionuclides, which may occur in all fields of peaceful uses of nuclear energy, depends on the gastrointestinal tract as the critical organ and on the composition of the fission product mixture. The influence of fractionation on the MPC can be reglected in such a case, whereas in case of soluble radionuclides this is not possible

Thin-target excitation functions: a powerful tool for optimizing yield, radionuclidic purity and specific activity of cyclotron produced radionuclides

International Nuclear Information System (INIS)

Bonardi, M.L.

2002-01-01

loci of the maxima of Y(E,ΔE) curves are present in most cases. As a relevant conclusion, use of target thickness larger than the 'effective' value, is unsuitable from technological point of view, due to larger power density deposited by the beam in target material itself, instead of target cooling system. Finally, this set of Thick-Target Yields and maxima permits calculating the optimum irradiation conditions to produce radionuclides with higher as possible yield, radionuclidic purity and specific activity. In order to join the advantages of the accurate knowledge of thin-target excitation functions and cross-sections of radionuclide of interest and its radioisotopic impurities, very selective radiochemical separations were optimized to separate the radionuclide itself from the irradiated target without any addition of isotopic carrier. A large number of very high specific activity radionuclides for environmental, toxicological and biomedical research applications have been produced in No Carrier Added form, by medium energy proton, deuteron and alpha accelerating cyclotrons. Some practical examples of radionuclides produced recently are presented. (author)

Effects of radionuclide decay on waste glass behavior: A critical review

International Nuclear Information System (INIS)

Wronkiewicz, D.J.

1993-12-01

This paper is an extension of a chapter in an earlier report [1] that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact

Cobalt-60 control in Ontario Hydro reactors

International Nuclear Information System (INIS)

Lacy, C.S.

1988-01-01

This paper discusses the impact of specifying reduced Cobalt-59 in the primary heat transport circuit materials of construction on the radiation fields developed around the primary circuit. An eight-fold reduction in steam generator radiation fields due to Cobalt-60 has been observed for two identical sets of reactors, one with and one without Cobalt-59 control. The comparison is between eight reactors at the Pickering Nuclear Generating Station (PNGS). Units 5 to 8 (PNGS-B) are identical to Units 1 to 4 (PNGS-A) except that PNGS-B has reduced impurity Cobalt-59 in the alloys of construction and a reduced use of stellite. The effects of chemistry control are also discussed

Radionuclides in Bayer process residues: previous analysis for radiological protection

International Nuclear Information System (INIS)

Cuccia, Valeria; Rocha, Zildete; Oliveira, Arno H. de

2011-01-01

Natural occurring radionuclides are present in many natural resources. Human activities may enhance concentrations of radionuclides and/or enhance potential of exposure to naturally occurring radioactive material (NORM). The industrial residues containing radionuclides have been receiving a considerable global attention, because of the large amounts of NORM containing wastes and the potential long term risks of long-lived radionuclides. Included in this global concern, this work focuses on the characterization of radioactivity in the main residues of Bayer process for alumina production: red mud and sand samples. Usually, the residues of Bayer process are named red mud, in their totality. However, in the industry where the samples were collected, there is an additional residues separation: sand and red mud. The analytical techniques used were gamma spectrometry (HPGe detector) and neutron activation analysis. The concentrations of radionuclides are higher in the red mud than in the sand. These solid residues present activities concentrations enhanced, when compared to bauxite. Further uses for the residues as building material must be more evaluated from the radiological point of view, due to its potential of radiological exposure enhancement, specially caused by radon emission. (author)

Proceedings of Soil Decon `93: Technology targeting radionuclides and heavy metals

Energy Technology Data Exchange (ETDEWEB)

1993-09-01

The principal objective for convening this workshop was to exchange ideas and discuss with scientists and engineers methods for removing radionuclides and/or toxic metals from soils. Over the years there have been numerous symposia, conferences, and workshops directed at soil remediation. However, this may be the first where the scope was narrowed to the removal of radionuclides and toxic metals from soils. The intent was to focus on the separation processes controlling the removal of the radionuclide and/or metal from soil. Its purpose was not intended to be a soil washing/leaching workshop, but rather to identify a variety or combination of processes (chemical, physical, and biological) that can be used in concert with the applicable engineering approaches to decontaminate soils of radionuclides and toxic metals. Abstracts and visual aids used by the speakers of the workshop are presented in this document.

Proceedings of Soil Decon '93: Technology targeting radionuclides and heavy metals

International Nuclear Information System (INIS)

1993-09-01

The principal objective for convening this workshop was to exchange ideas and discuss with scientists and engineers methods for removing radionuclides and/or toxic metals from soils. Over the years there have been numerous symposia, conferences, and workshops directed at soil remediation. However, this may be the first where the scope was narrowed to the removal of radionuclides and toxic metals from soils. The intent was to focus on the separation processes controlling the removal of the radionuclide and/or metal from soil. Its purpose was not intended to be a soil washing/leaching workshop, but rather to identify a variety or combination of processes (chemical, physical, and biological) that can be used in concert with the applicable engineering approaches to decontaminate soils of radionuclides and toxic metals. Abstracts and visual aids used by the speakers of the workshop are presented in this document

49 CFR 1242.57 - Dispatching trains (account XX-51-58).

Science.gov (United States)

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Dispatching trains (account XX-51-58). 1242.57 Section 1242.57 Transportation Other Regulations Relating to Transportation (Continued) SURFACE...-Transportation § 1242.57 Dispatching trains (account XX-51-58). Separate common expenses on the basis of train...

An elevator for cobalt-60 source

International Nuclear Information System (INIS)

Tang Zaimin; Liang Donghu

1990-07-01

The elevator used for cobalt-60 source is a key device in the irradiation industry. It plays an important role in the safety and control of irradiation operation as well as the utilization rate of radiation source. From 1983 to 1986, Beijing Institute of Nuclear Engineering undertook designing of various size irradiation projects for different uses. Since then a kind of cobalt-60 source elevator suited for the irradiator of wet-source-storage has been chosen. It is reliable in the operation and complete in the function. An automatic control circuit brings the systems of cobalt-60 source elevator into an interlock system which ensures the irradiation operation safety. Besides introducing the structural features and performance of this elevator, the conditions of safety interlocking in raising or lowering the cobalt-60 source is also discussed. The discussion is from the safety viewpoint of operating an irradiator and irradiation technology

Development of long-lived radionuclide partitioning technology

International Nuclear Information System (INIS)

Lee, Eil Hee; Kwon, S. G.; Yang, H. B.

2001-04-01

This project was aimed at the development of an optimal process that could get recovery yields of 99% for Am and Np and 90% for Tc from a simulated radioactive waste and the improvements of unit processes. The performed works are summarized, as follows. 1) The design and the establishment of a laboratory-scale partitioning process were accomplished, and the interfacial conditions between each unit process were determined. An optimal flow diagram for long-lived radionuclide partitioning process was suggested. 2) In improvements of unit processes, a) Behaviors of the co-extraction and sequential separation for residual U, Np and Tc(/Re) by chemical and electrochemical methods were examined. b) Conditions for co-extraction of Am/RE, and selective stripping of Am with metal containing extractant and a mixed extractant were decided. c) Characteristics of adsorption and elution by ion exchange chromatography and extraction chromatography methods were analysed. d) The simulation codes for long-lived radionuclide partitioning were gathered. and reaction equations were numerically formulated. 3) An existing γ-lead cell was modified the α-γ cells for treatment of long-lived radioactive materials. 4) As the applications of new separation technologies, a) Behaviors of photo reductive precipitation for Am/RE were investigated, b) Conditions for selective extraction and stripping of Am with pyridine series extractants were established. All results will be used as the fundamental data for establishment of partitioning process and radiochemical test of long-lived radionuclides recovery technology to be performed in the next stage

21 CFR 73.1015 - Chromium-cobalt-aluminum oxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Chromium-cobalt-aluminum oxide. 73.1015 Section 73... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1015 Chromium-cobalt-aluminum oxide. (a) Identity. The color additive chromium-cobalt-aluminum oxide is a blue-green pigment obtained by calcining a...

Feasibility test for production and separation of 103Pd

International Nuclear Information System (INIS)

Szuecs, Z.; Takacs, S.; Hunyadi, M.; Gacsi, Z.; Zeevaart, J.R.

2011-01-01

Complete text of publication follows. 103 Pd as a well-known Auger-emitter is commonly employed in brachytherapy, but the ultra-short range stopping of Auger-electrons can be more potentially exploited in applications of targeted radionuclide therapy in the future. The no-carrier-added production of 103 Pd is practically possible through charged particle induced reactions. However, separation techniques of 103 Pd from the target material (typically Rh), as well as its recovery by wet chemistry are expensive, and yields high amounts of radioactive waste. An alternative and more efficient procedure, called drydistillation method (DDM), is based on differences between the isothermal vapor pressures of the radionuclide element and the target element. In an appropriately selected temperature region the diffusion and out-gassing rates of radionuclides from the solid matrix of the target material are enhanced. Optimal irradiation parameters were determined in previous experiments at ATOMKI. Separation of 103 Pd was demonstrated at the Isotope Separator Laboratory with an evaporating-condensing system (Fig. 1). Figure 1. Evaporation-condensation system at the Isotope Separator Laboratory of ATOMKI. The irradiated Rh foil was kept above 1800?C in vacuum for several hours. The evaluation of γ-spectra of the Rh foil and the 103 Pd condensed on a low-temperature substrate (Fig. 2). The analysis resulted in a radiochemical yield of about 99.5% for 103 Pd and a radionuclidic purity of better than 99% with respect to the level of 101 Rh in the end product. Acknowledgement. The work was partly supported by the Hungarian TeT Bilateral Cooperation (OMFB- 00138/2009) and by the South African NRF (UID 68768).

Log live high activity radioactive wastes / Researches and results law of the 30 December 1991. Separation and transmutation of long lived radionuclides; Les dechets radioactifs a haute activite et a vie longue / recherches et resultats Loi du 30 decembre 1991. Separation et transmutation des radionucleides a vie longue

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-12-15

The law of the 30 December 1991 on the high activity long lived radioactive wastes reached the end. This synthesis final document presents the scientific and technological results, obtained still the end of 2005, on the separation and the transmutation of long lived radionuclides of high activity long lived radioactive wastes. It is organized in five chapters: a presentation of the context and the historical aspects, the researches, the objectives and the strategy of the axis 1, the researches results on the advanced separation, the researches results on the transmutation, the scenario of separation-transmutation and their environmental, technical and economical impacts. (A.L.B.)

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

Directory of Open Access Journals (Sweden)

Byung-Sik Lee

2015-12-01

Full Text Available The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst–Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Sik [KEPCO Engineering and Construction, Gimcheon (Korea, Republic of)

2015-12-15

The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO) membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst-Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

Cobalt release from inexpensive jewellery: has the use of cobalt replaced nickel following regulatory intervention?

DEFF Research Database (Denmark)

Thyssen, Jacob Pontoppidan; Jellesen, Morten S; Menné, Torkil

2010-01-01

Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure.......Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure....

Enrichment and Determination of radionuclides by ion chromatography

International Nuclear Information System (INIS)

ZAFIMANJATO, J.L.R.

1996-01-01

The fundamentals of Ion Chromatography (IC) and Liquid Scintillation Counting (LSC) are reviewed. Ion Chromatography as separation method for cations is coupled with Liquid Scintillation Counting for the determination of Radionuclides in water samples. An experimental arrangement for investigations on the applicability of guard columns for cationic radionuclide enrichment is shown. The saturation behaviour of single and bivalentic cations and their combination is presented. Our results show that radioactive bivalentic cations like strontium-90 and radium-226 are enriched on a Ion Pac CG 12 Dionex guard column from 100 to 300ml natural water in one single step. The procedure is suitable for their determination in concentrations down to 10 -2 Bq.l -1 [fr

Study of extraction chromatography methods of separation of neptunium and its radiometric determination

International Nuclear Information System (INIS)

Reich, M.

2009-04-01

In presented dissertation thesis the separation procedure for determination of neptunium in model solutions and also in soil samples was designed. 1. The sorbent was prepared on basis of hydrophobised silica gel with silica oil for hydrophobisation - Lukooil H. Extraction agent was anchored on this modified surface -quarternary ammonium salt Aliquat 336. In experiments was proved, that sorbent prepared like this is resist enough to the elution solutions using in separation procedures. It was found out that maximal concentration of deposited Aliquat 336 in benzene on hydrophobised silica gel selected granulate size is 40%. Sorbent prepared with silica gel lower granulate size and also with higher concentration of Aliquat 336 in benzene became sticky and unsuitable for using in separation columns. 2. The prepared sorbent is similar to commercial produced TEVA resin made by company Eichrom and for purpose of this project it was cheaper but the same effective alternative in comparing to mentioned commercial resin. 3. The separation procedure for isolation of 237 Np from radionuclides interfering during its radiometric determination with alpha spectrometry was designed -in scientific publications hasn't been described yet. The procedure consists of using formic acid for reduction of radionuclides interfering by alpha spectrometric determination of 237 Np and subsequent purification of neptunium on the next column by using ferrous sulphamate as reduction agent. This procedure was applied to the model solutions and also to the soil samples. The model solutions and soil samples for these experiments were contaminated with known amounts of 237 Np, 238 pU, 232 Th and mixture of 234 U/ 238 U. The effective separation of neptunium from described radionuclides was achieved with application of the described separation procedure. 4. The separation procedure for separation of 239 Np from its mother radionuclide 241 Am was designed with prepared sorbent. Different washing and

Radionuclide cisternography

International Nuclear Information System (INIS)

Song, H.H.

1980-01-01

The purpose of this thesis is to show that radionuclide cisternography makes an essential contribution to the investigation of cerebrospinal fluid (CSF) dynamics, especially for the investigation of hydrocephalus. The technical details of radionuclide cisternography are discussed, followed by a description of the normal and abnormal radionuclide cisternograms. The dynamics of CFS by means of radionuclide cisternography were examined in 188 patients in whom some kind of hydrocephalus was suspected. This study included findings of anomalies associated with hydrocephalus in a number of cases, such as nasal liquorrhea, hygromas, leptomeningeal or porencephalic cysts. The investigation substantiates the value of radionuclide cisternography in the diagnosis of disturbances of CSF flow. The retrograde flow of radiopharmaceutical into the ventricular system (ventricular reflux) is an abnormal phenomenon indicating the presence of communicating hydrocephalus. (Auth.)

Thermal effect on structure organizations in cobalt-fullerene nanocomposition.

Science.gov (United States)

Lavrentiev, Vasily; Vacik, Jiri; Naramoto, Hiroshi; Sakai, Seiji

2010-04-01

Effect of deposition temperature (Ts) on structure of Co-C60 nanocomposite (NC) prepared by simultaneous deposition of cobalt and fullerene on sapphire is presented. The NC structure variations with Ts increasing from room temperature (RT) to 400 degrees C have been analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy. AFM and SEM show granule-like structure of the Co-C60 film. The mixture film deposited at RT includes the hills on the surface suggesting accumulation of internal stress during phase separation. Raman spectra show 25 cm(-1) downshift of Ag(2) C60 peak suggesting -Co-C60- polymerization in C60-based matrix of the NC film. Analysis of Raman spectra has revealed existence of amorphous carbon (a-C) in the NC matrix that argues C60 decomposition. The Ts increase to 200 degrees C causes the surface hills smoothing. In parallel, downshift of the Ag(2) peak decreases to 16 cm(-1) that implies more pronounced phase separation and lower -Co-C60- polymerization efficiency. Also, amount of a-C content slightly increases. Further Ts increasing to 400 degrees C changes the NC structure dramatically. AFM shows evident enlargement of the granules. According to Raman spectra the high Ts deposition yields pronounced C60 decomposition increasing the a-C content. Features of a-C Raman peak imply nucleation of graphitic islands at the NC interfaces. Abundant decomposition of C60 in the mixture film deposited at 400 degrees C is referred to cobalt catalytic effect.

The role of cobalt on the creep of Waspaloy

Science.gov (United States)

Jarrett, R. N.; Chin, L.; Tien, J. K.

1984-01-01

Cobalt was systematically replaced with nickel in Waspaloy (which normally contains 13% Co) to determine the effects of cobalt on the creep behavior of this alloy. Effects of cobalt were found to be minimal on tensile strengths and microstructure. The creep resistance and the stress rupture resistance determined in the range from 704 to 760 C (1300 to 1400 C) were found to decrease as cobalt was removed from the standard alloy at all stresses and temperatures. Roughly a ten-fold drop in rupture life and a corresponding increase in minimum creep rate were found under all test conditions. Both the apparent creep activation energy and the matrix contribution to creep resistance were found to increase with cobalt. These creep effects are attributed to cobalt lowering the stacking fault energy of the alloy matrix. The creep resistance loss due to the removal of cobalt is shown to be restored by slightly increasing the gamma' volume fraction. Results are compared to a previous study on Udimet 700, a higher strength, higher gamma' volume fraction alloy with similar phase chemistry, in which cobalt did not affect creep resistance. An explanation for this difference in behavior based on interparticle spacing and cross-slip is presented.

Interception and translocation of radionuclides in major food crops for Koreans

International Nuclear Information System (INIS)

Choi, Y. H.; Lim, K. M.; Park, H. G.; Choi, H. J.; Lee, H. S.

2002-01-01

In order to investigate the direct plant contamination pathway of 54 Mn, 57 Co, 85 Sr, 103 Ru and 134 Cs in major food crops for Koreans, rice, soybean and radish plants at different growth stages were sprayed with radioactive solutions in a greenhouse. The interception factor and the translocation factor were quantified as the fraction of the total deposition that is initially retained on the aboveground plant surface and the fraction of the total initial plant activity that is contained in the edible part at harvest, respectively. In rice and radish, interception factors increased as plants grew old to harvest. In soybean, however, rapid defoliation in old plants made interception factors decrease with increasing age during the later part of the growth. There was little difference in the interception factor among radionuclides. Translocation factors decreased in the order of 134 Cs ≥> 57 Co > 54 Mn ≥ 85 Sr > 103 Ru in general and varied with radionuclides by factors of 6-4000, depending on application time and plant species. Translocation factors for rice seeds were the highest when radionuclides were applied at the active seed growth stage and those for soybean seeds were the highest following the application at the early pod-filling stage except for 103 Ru. For radish roots, translocation factors were on the whole the highest following the early- growth-stage application. The obtained data can be used for parameter values in food-chain dose assessment models especially for Koreans and many other Asian people

Interception and translocation of radionuclides in major food crops for Koreans

Energy Technology Data Exchange (ETDEWEB)

Choi, Y. H.; Lim, K. M.; Park, H. G.; Choi, H. J.; Lee, H. S. [KAERI, Daejon (Korea, Republic of)

2002-07-01

In order to investigate the direct plant contamination pathway of {sup 54}Mn, {sup 57}Co, {sup 85}Sr, {sup 103}Ru and {sup 134}Cs in major food crops for Koreans, rice, soybean and radish plants at different growth stages were sprayed with radioactive solutions in a greenhouse. The interception factor and the translocation factor were quantified as the fraction of the total deposition that is initially retained on the aboveground plant surface and the fraction of the total initial plant activity that is contained in the edible part at harvest, respectively. In rice and radish, interception factors increased as plants grew old to harvest. In soybean, however, rapid defoliation in old plants made interception factors decrease with increasing age during the later part of the growth. There was little difference in the interception factor among radionuclides. Translocation factors decreased in the order of {sup 134}Cs {>=}> {sup 57}Co > {sup 54}Mn {>=} {sup 85}Sr >{sup 103}Ru in general and varied with radionuclides by factors of 6-4000, depending on application time and plant species. Translocation factors for rice seeds were the highest when radionuclides were applied at the active seed growth stage and those for soybean seeds were the highest following the application at the early pod-filling stage except for {sup 103}Ru. For radish roots, translocation factors were on the whole the highest following the early- growth-stage application. The obtained data can be used for parameter values in food-chain dose assessment models especially for Koreans and many other Asian people.

Nickel-cobalt hydroxide nanosheets: Synthesis, morphology and electrochemical properties.

Science.gov (United States)

Schneiderová, Barbora; Demel, Jan; Zhigunov, Alexander; Bohuslav, Jan; Tarábková, Hana; Janda, Pavel; Lang, Kamil

2017-08-01

This paper reports the synthesis, characterization, and electrochemical performance of nickel-cobalt hydroxide nanosheets. The hydroxide nanosheets of approximately 0.7nm thickness were prepared by delamination of layered nickel-cobalt hydroxide lactate in water and formed transparent colloids that were stable for months. The nanosheets were deposited on highly oriented pyrolytic graphite by spin coating, and their electrochemical behavior was investigated by cyclic voltammetry in potassium hydroxide electrolyte. Our method of electrode preparation allows for studying the electrochemistry of nanosheets where the majority of the active centers can participate in the charge transfer reaction. The observed electrochemical response was ascribed to mutual compensation of the cobalt and nickel response via electron sharing between these metals in the hydroxide nanosheets, a process that differentiates the behavior of nickel-cobalt hydroxide nanosheets from single nickel hydroxide or cobalt hydroxide nanosheets or their physical mixture. The presence of cobalt in the nickel-cobalt hydroxide nanosheets apparently decreases the time of electrochemical activation of the nanosheet layer, which for the nickel hydroxide nanosheets alone requires more potential sweeps. Copyright © 2017 Elsevier Inc. All rights reserved.

The Nuclear Data Commission and the Radionuclide Data Centre in Russia

International Nuclear Information System (INIS)

1994-12-01

The document includes two papers: 'The Work of the Nuclear Data Commission' and 'Radionuclide Data Centre', which describe the activities of these two organizations of the Russian Federation. A separate abstract was prepared for each paper

A study of radionuclide transfer between invertebrates and their marine sedimentary environment

International Nuclear Information System (INIS)

Amiard-Triquet, Claude.

1975-11-01

Exchanges between sediment and marine organisms were studied in some benthic marine invertebrates, especially Arenicola marina L. (an Annelid). Experiments were carried out on the transfer of 60 Co, 137 Cs and accessorily 59 Fe and 144 Ce. Water was the chief vector for benthic marine invertebrates. These invertebrates seemed to act mainly in sedimentary areas on the redistribution of adsorbed radionuclides within the sediment. Radioactive contamination of the invertebrates was affected by various physiological or ecological factors. Benthic marine invertebrates were then studied as links in food chains. The transfer of 60 Co was studied in three food chains or fractions of food chains. The procedure allowed interesting observations from the health protection point of view and more fundamental investigations on cobalt metabolism (regulation, excretion) in a mollusc, a crustacea and a teleost [fr

Airborne anthropogenic radioactivity measurements from an international radionuclide monitoring system

International Nuclear Information System (INIS)

Mason, L.R.; Bohner, J.D.; Williams, D.L.

1998-01-01

Anthropogenic radioactivity is being measured in near-real time by an international monitoring system designed to verify the Comprehensive Nuclear Test Ban Treaty. Airborne radioactivity measurements are conducted in-situ by stations that are linked to a central data processing and analysis facility. Aerosols are separated by high-volume air sampling with high-efficiency particulate filters. Radio-xenon is separated from other gases through cryogenic methods. Gamma-spectrometry is performed by high purity germanium detectors and the raw spectral data is immediately transmitted to the central facility via Internet, satellite, or modem. These highly sensitive sensors, combined with the automated data processing at the central facility, result in a system capable of measuring environmental radioactivity on the microbecquerel scale where the data is available to scientists within minutes of the field measurement. During the past year, anthropogenic radioactivity has been measured at approximately half of the stations in the current network. Sources of these measured radionuclides include nuclear power plant emissions, Chernobyl resuspension, and isotope production facilities. The ability to thoroughly characterize site-specific radionuclides, which contribute to the radioactivity of the ambient environment, will be necessary to reduce the number of false positive events. This is especially true of anthropogenic radionuclides that could lead to ambiguous analysis. (author)

COBALT COMPOUNDS AS ANTIDOTES FOR HYDROCYANIC ACID.

Science.gov (United States)

EVANS, C L

1964-12-01

The antidotal potency of a cobalt salt (acetate), of dicobalt edetate, of hydroxocobalamin and of cobinamide against hydrocyanic acid was examined mainly on mice and rabbits. All the compounds were active antidotes for up to twice the LD50; under some conditions for larger doses. The most successful was cobalt acetate for rabbits (5xLD50), which was effective at a molar cyanide/cobalt (CN/Co) ratio of 5, but had as a side-effect intense purgation. Hydroxocobalamin was irregular in action, but on the whole was most effective for mice (4.5xLD50 at a molar ratio of 1), and had no apparent side effects. Dicobalt edetate, at molar ratios of up to 2, was more effective for rabbits (3xLD50) than for mice (2xLD50), but had fewer side effects than cobalt acetate. The effect of thiosulphate was to augment the efficacy of dicobalt edetate and, in mice, that of hydroxocobalamin; but, apparently, in rabbits, to reduce that of hydroxocobalamin. Cobinamide, at a molar ratio of 1, was slightly more effective than hydroxocobalamin on rabbits and also less irregular in its action. Cobalt acetate by mouth was effective against orally administered hydrocyanic acid. The oxygen uptake of the body, reduced by cyanide, is rapidly reinstated when one of the cobalt antidotes has been successfully administered.

TECHNOLOGY DEVELOPMENT FOR IRON AND COBALT FISCHER-TROPSCH CATALYSTS

Energy Technology Data Exchange (ETDEWEB)

Burtron H. Davis

1999-01-30

The effects of copper on Fischer-Tropsch activity, selectivity and water-gas shift activity were studied over a wide range of syngas conversion. Three catalyst compositions were prepared for this study: (a) 100Fe/4.6Si/1.4K, (b) 100Fe/4.6Si/0.10Cu/1.4K and (c) 100Fe/4.6Si/2.0Cu/1.4K. The results are reported in Task 2. The literature review for cobalt catalysts is approximately 90% complete. Due to the size of the document, it has been submitted as a separate report labeled Task 6.

Characterization of a Porous Carbon Material Functionalized with Cobalt-Oxide/Cobalt Core-Shell Nanoparticles for Lithium Ion Battery Electrodes

KAUST Repository

Anjum, Dalaver H.; Rasul, Shahid; Roldan-Gutierrez, Manuel A.; Da Costa, Pedro M. F. J.

2016-01-01

A nanoporous carbon (C) material, functionalized with Cobalt-Oxide/Cobalt (CoO/Co) core-shell nanoparticles (NPs), was structurally and chemically characterized with transmission electron microcopy (TEM) while its electrochemical response

Cobalt mineral exploration and supply from 1995 through 2013

Science.gov (United States)

Wilburn, David R.

2011-01-01

The global mining industry has invested a large amount of capital in mineral exploration and development over the past 15 years in an effort to ensure that sufficient resources are available to meet future increases in demand for minerals. Exploration data have been used to identify specific sites where this investment has led to a significant contribution in global mineral supply of cobalt or where a significant increase in cobalt production capacity is anticipated in the next 5 years. This report provides an overview of the cobalt industry, factors affecting mineral supply, and circumstances surrounding the development, or lack thereof, of key mineral properties with the potential to affect mineral supply. Of the 48 sites with an effective production capacity of at least 1,000 metric tons per year of cobalt considered for this study, 3 producing sites underwent significant expansion during the study period, 10 exploration sites commenced production from 1995 through 2008, and 16 sites were expected to begin production by 2013 if planned development schedules are met. Cobalt supply is influenced by economic, environmental, political, and technological factors affecting exploration for and production of copper, nickel, and other metals as well as factors affecting the cobalt industry. Cobalt-rich nickel laterite deposits were discovered and developed in Australia and the South Pacific and improvements in laterite processing technology took place during the 1990s and early in the first decade of the 21st century when mining of copper-cobalt deposits in Congo (Kinshasa) was restricted because of regional conflict and lack of investment in that country's mining sector. There was also increased exploration for and greater importance placed on cobalt as a byproduct of nickel mining in Australia and Canada. The emergence of China as a major refined cobalt producer and consumer since 2007 has changed the pattern of demand for cobalt, particularly from Africa and

The cytotoxicity and genotoxicity of soluble and particulate cobalt in human lung fibroblast cells

Energy Technology Data Exchange (ETDEWEB)

Smith, Leah J.; Holmes, Amie L. [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Kandpal, Sanjeev Kumar; Mason, Michael D. [Department of Chemical and Biological Engineering, University of Maine, Orono, ME (United States); Zheng, Tongzhang [Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT (United States); Wise, John Pierce, E-mail: John.Wise@usm.maine.edu [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Maine Center for Environmental Toxicology and Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04101-9300 (United States)

2014-08-01

Cobalt exposure is increasing as cobalt demand rises worldwide due to its use in enhancing rechargeable battery efficiency, super-alloys, and magnetic products. Cobalt is considered a possible human carcinogen with the lung being a primary target. However, few studies have considered cobalt-induced toxicity in human lung cells. Therefore, in this study, we sought to determine the cytotoxicity and genotoxicity of particulate and soluble cobalt in human lung cells. Cobalt oxide and cobalt chloride were used as representative particulate and soluble cobalt compounds, respectively. Exposure to both particulate and soluble cobalt induced a concentration-dependent increase in cytotoxicity, genotoxicity, and intracellular cobalt ion levels. Based on intracellular cobalt ion levels, we found that soluble cobalt was more cytotoxic than particulate cobalt while particulate and soluble cobalt induced similar levels of genotoxicity. However, soluble cobalt induced cell cycle arrest indicated by the lack of metaphases at much lower intracellular cobalt concentrations compared to cobalt oxide. Accordingly, we investigated the role of particle internalization in cobalt oxide-induced toxicity and found that particle-cell contact was necessary to induce cytotoxicity and genotoxicity after cobalt exposure. These data indicate that cobalt compounds are cytotoxic and genotoxic to human lung fibroblasts, and solubility plays a key role in cobalt-induced lung toxicity. - Highlights: • Particulate and soluble cobalt are cytotoxic and genotoxic to human lung cells. • Soluble cobalt induces more cytotoxicity compared to particulate cobalt. • Soluble and particulate cobalt induce similar levels of genotoxicity. • Particle-cell contact is required for particulate cobalt-induced toxicity.

Making a robust carbon-cobalt(III) bond

DEFF Research Database (Denmark)

Larsen, Erik; Madsen, Anders Østergaard; Kofod, Pauli

2009-01-01

The coordination ion with a well-characterized carbon-cobalt(III) bond, the (1,4,7-triazacyclononane)(1,6-diamino-3-thia-4-hexanido)cobalt(III) dication, [Co(tacn)(C-aeaps)](2+) (aeaps, for aminoethylaminopropylsulfide), has been reacted with iodomethane, and the S-methyl thionium derivative has...... been isolated. The crystal structure of the resulting [Co(tacn)(C-aeaps-SCH(3))]Br(3) x 3 H(2)O at 122 K has been determined by X-ray diffraction techniques to verify the structure. The crystal structure determination shows that the carbon-cobalt bond length is even shorter (2.001(4) A) than in [Co......(tacn)(C-aeaps)](2+) participates in bonding to cobalt(III), having implications for the transformation between the carbon- and sulfur-bound forms of the aeaps ligand....

RADIONUCLIDE DISPERSION RATES BY AEOLIAN, FLUVIAL, AND POROUS MEDIA TRANSPORT

International Nuclear Information System (INIS)

Walton, J.; Goodell, P.; Brashears, C.; French, D.; Kelts, A.

2005-01-01

Radionuclide transport was measured from high grade uranium ore boulders near the Nopal I Site, Chihuahua, Mexico. High grade uranium ore boulders were left behind after removal of a uranium ore stockpile at the Prior High Grade Stockpile (PHGS). During the 25 years when the boulder was present, radionuclides were released and transported by sheetflow during precipitation events, wind blown resuspension, and infiltration into the unsaturated zone. In this study, one of the boulders was removed, followed by grid sampling of the surrounding area. Measured gamma radiation levels in three dimensions were used to derive separate dispersion rates by the three transport mechanisms

RADIONUCLIDE DISPERSION RATES BY AEOLIAN, FLUVIAL, AND POROUS MEDIA TRANSPORT

Energy Technology Data Exchange (ETDEWEB)

J. Walton; P. Goodell; C. Brashears; D. French; A. Kelts

2005-07-11

Radionuclide transport was measured from high grade uranium ore boulders near the Nopal I Site, Chihuahua, Mexico. High grade uranium ore boulders were left behind after removal of a uranium ore stockpile at the Prior High Grade Stockpile (PHGS). During the 25 years when the boulder was present, radionuclides were released and transported by sheetflow during precipitation events, wind blown resuspension, and infiltration into the unsaturated zone. In this study, one of the boulders was removed, followed by grid sampling of the surrounding area. Measured gamma radiation levels in three dimensions were used to derive separate dispersion rates by the three transport mechanisms.

Total body irradiation with a reconditioned cobalt teletherapy unit.

Science.gov (United States)

Evans, Michael D C; Larouche, Renée-Xavière; Olivares, Marina; Léger, Pierre; Larkin, Joe; Freeman, Carolyn R; Podgorsak, Ervin B

2006-01-01

While the current trend in radiotherapy is to replace cobalt teletherapy units with more versatile and technologically advanced linear accelerators, there remain some useful applications for older cobalt units. The expansion of our radiotherapy department involved the decommissioning of an isocentric cobalt teletherapy unit and the replacement of a column-mounted 4-MV LINAC that has been used for total body irradiation (TBI). To continue offering TBI treatments, we converted the decommissioned cobalt unit into a dedicated fixed-field total body irradiator and installed it in an existing medium-energy LINAC bunker. This article describes the logistical and dosimetric aspects of bringing a reconditioned cobalt teletherapy unit into clinical service as a total body irradiator.

A novel separation/preconcentration technique based on ultrasonic dispersion liquid-liquid microextraction for determination of trace cobalt by flame atomic absorption spectrometry

Directory of Open Access Journals (Sweden)

Jingci Li

2012-12-01

Full Text Available An improved method for the determination of trace cobalt in water samples has been developed using ultrasonic dispersion liquid-liquid microextraction (US-DLLME prior to flame atomic absorption spectrometry (FAAS analysis. In this method, cobalt was extracted into the fine droplets of carbon tetrachloride after chelate formation with the water soluble ligand, ammonium pyrrolidine dithiocarbamate (APDC. The fine droplets of carbon tetrachloride were formed and dispersed in the aqueous sample with the help of ultrasonic waves which accelerated the formation of the fine cloudy solution without using disperser solvents. Under optimum conditions, the calibration curve was linear in the range of 2.5-500 μg L-1, with a detection limit of 0.8 μg L-1. The relative standard deviation (RSD for ten replicate measurements of 20 and 500 μg L-1 of cobalt were 3.3 and 2.2%. This proposed method was successfully applied to tap water, river water, and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments. Operation simplicity, low cost, high enrichment factor, and low consumption of the extraction solvent are the main advantages of the proposed method.DOI: http://dx.doi.org/10.4314/bcse.v26i1.2

Development of an analytical model for the determination of {sup 60}Co in aqueous samples by atomic absorption and gamma spectrometry techniques; Elaboracion de un modelo analitico para la determinacion de {sup 60}Co en muestras acuosas mediante tecnicas de absorcion atomica y espectrometria gamma

Energy Technology Data Exchange (ETDEWEB)

Solis A, N. A.

2015-07-01

The applications of the nuclear energy in industry and medicine generate radioactive wastes that must be isolated and confined in order to limit its spread in the biosphere. These types of wastes are generated in hospitals, industry, research centers and nuclear power plants (during de fuel cycle). The radioactive elements (radionuclides) cannot be destroyed by any known method, either chemical or mechanical. Its final destruction is produced by radioactive decay, which makes them stable isotopes, or nuclear transmutation being bombarded with atomic particles. Consequently, the radioactive waste management is to control the radioactive discharges and reduce to tolerable limits, eliminating of effluents and wastes the radionuclides of interest, concentrating them so they can be stored or evacuated so that later not appear in dangerous concentration in the biosphere. In Mexico, the main generators of radioactive wastes are the nuclear power plant of Laguna Verde in Veracruz, Hospitals of the public and private sector, in addition Instituto Nacional de Investigaciones Nucleares (ININ) some institutes and facilities of the UNAM and Instituto Politecnico Nacional (IPN) and industries among others. The aqueous radioactive wastes, particularly those from the nuclear power plants contain traces of cobalt-60. Currently there is no model or analytical technique for the separation of this radionuclide, so it became necessary to develop an analytical model for separation and facilitate their disposal. In this paper was shown that atomic absorption and gamma spectrometry techniques can separate the active concentration of the inactive, which is important because the total concentration can be associated through direct relationships with the wear of metal parts of the nuclear reactor, since the metal alloys of the same reactor containing a fraction of cobalt. Also this analytical and mathematical model that can be reproducible and applicable to full sets of samples and that this

Development of an analytical model for the determination of 60Co in aqueous samples by atomic absorption and gamma spectrometry techniques

International Nuclear Information System (INIS)

Solis A, N. A.

2015-01-01

The applications of the nuclear energy in industry and medicine generate radioactive wastes that must be isolated and confined in order to limit its spread in the biosphere. These types of wastes are generated in hospitals, industry, research centers and nuclear power plants (during de fuel cycle). The radioactive elements (radionuclides) cannot be destroyed by any known method, either chemical or mechanical. Its final destruction is produced by radioactive decay, which makes them stable isotopes, or nuclear transmutation being bombarded with atomic particles. Consequently, the radioactive waste management is to control the radioactive discharges and reduce to tolerable limits, eliminating of effluents and wastes the radionuclides of interest, concentrating them so they can be stored or evacuated so that later not appear in dangerous concentration in the biosphere. In Mexico, the main generators of radioactive wastes are the nuclear power plant of Laguna Verde in Veracruz, Hospitals of the public and private sector, in addition Instituto Nacional de Investigaciones Nucleares (ININ) some institutes and facilities of the UNAM and Instituto Politecnico Nacional (IPN) and industries among others. The aqueous radioactive wastes, particularly those from the nuclear power plants contain traces of cobalt-60. Currently there is no model or analytical technique for the separation of this radionuclide, so it became necessary to develop an analytical model for separation and facilitate their disposal. In this paper was shown that atomic absorption and gamma spectrometry techniques can separate the active concentration of the inactive, which is important because the total concentration can be associated through direct relationships with the wear of metal parts of the nuclear reactor, since the metal alloys of the same reactor containing a fraction of cobalt. Also this analytical and mathematical model that can be reproducible and applicable to full sets of samples and that this

Solidification of 137Cs into potassium cobalt hexacyanoferrate (II) ion exchanger

International Nuclear Information System (INIS)

Lehto, J.; Harjula, R.; Haukka, S.; Wallace, J.

1989-01-01

An inorganic ion exchange, potassium cobalt hexacyanoferrate(II), has been studied for the separation of 137 Cs from nuclear waste solutions. This exchanges is highly selective for cesium over other alkali metal ions and can be synthesized in granular form suitable for column operations. Pilot-plant experiments were carried out at a NPP to test the exchanges for solidification of 137 Cs from an evaporator concentrate. The results were encouraging: decontamination factors and volume reduction factors were both very high. A full-scale separation plant is now under construction plans call for the exchanges, loaded with 137 Cs, to be disposed of in stainless steel columns, sealed by welding and enclosed in concrete block. According to the authors this multibarrier procedure provides a safe final disposal solution

Temperature dependent viscosity of cobalt ferrite / ethylene glycol ferrofluids

Science.gov (United States)

Kharat, Prashant B.; Somvanshi, Sandeep B.; Kounsalye, Jitendra S.; Deshmukh, Suraj S.; Khirade, Pankaj P.; Jadhav, K. M.

2018-04-01

In the present work, cobalt ferrite / ethylene glycol ferrofluid is prepared in 0 to 1 (in the step of 0.2) volume fraction of cobalt ferrite nanoparticles synthesized by co-precipitation method. The XRD results confirmed the formation of single phase spinel structure. The Raman spectra have been deconvoluted into individual Lorentzian peaks. Cobalt ferrite has cubic spinel structure with Fd3m space group. FT-IR spectra consist of two major absorption bands, first at about 586 cm-1 (υ1) and second at about 392 cm-1 (υ2). These absorption bands confirm the formation of spinel-structured cobalt ferrite. Brookfield DV-III viscometer and programmable temperature-controlled bath was used to study the relationship between viscosity and temperature. Viscosity behavior with respect to temperature has been studied and it is revealed that the viscosity of cobalt ferrite / ethylene glycol ferrofluids increases with an increase in volume fraction of cobalt ferrite. The viscosity of the present ferrofluid was found to decrease with increase in temperature.

Cobalt 60 cation exchange with mexican clays

International Nuclear Information System (INIS)

Nava Galve, R.G.

1993-01-01

Mexican clays can be used to remove radioactive elements from contaminated aqueous solutions. Cation exchange experiments were performed with 60 Co radioactive solution. In the present work the effect of contact time on the sorption of Co 2+ was studied. The contact time in hydrated montmorillonite was from 5 to 120 minutes and in dehydrated montmorillonite 5 to 1400 minutes. The Co 2+ uptake value was, in hydrated montmorillonite, between 0.3 to 0.85 m eq/g and in dehydrated montmorillonite, between 0.6 to 1.40 m eq/g. The experiments were done in a pH 5.1 to 5.7 and normal conditions. XRD patterns were used to characterize the samples. The crystallinity was determined by X-ray Diffraction and it was maintained before and after the cation exchange. DTA thermo grams showed the temperatures of the lost humidity and crystallization water. Finally, was observed that dehydrated montmorillonite adsorb more cobalt than hydrated montmorillonite. (Author)

Synthesis of cobalt boride nanoparticles using radio frequency thermal plasma

International Nuclear Information System (INIS)

Lapitan, Jr. Lorico DS.; Ying Ying Chen; Seesoek Choe; Watanabe, Takayuki

2012-01-01

Nano size cobalt boride particles were synthesized from vapor phase using a 30 kw-4 MHz radio frequency (RF) thermal plasma. Cobalt and boron powder mixtures used as precursors in different composition and feed rate were evaporated immediately in the high temperature plasma and cobalt boride nanoparticles were produced through the quenching process. The x-ray diffractometry (XRD) patterns of cobalt boride nanoparticles prepared from the feed powder ratio of 1:2 and 1:3 for Co: B showed peaks that are associated with the Co 2 B and CoB crystal phases of cobalt boride. The XRD analysis revealed that increasing the powder feed rate results in a higher mass fraction and a larger crystalline diameter of cobalt boride nanoparticles. The images obtained by field emission scanning electron microscopy (FE-SEM) revealed that cobalt boride nanoparticles have a spherical morphology. The crystallite size of the particles estimated with XRD was found to be 18-22 nm. (author)

Study to use graded cobalt adjuster in 540 MWe PHWR

International Nuclear Information System (INIS)

Raj, Manish; Fernando, M.P.S.; Pradhan, A.S.; Kumar, A.N.

2007-01-01

Full text: There are 17 adjusters in 540 MWe PHWR, which are essentially provided for xenon override function. They also provide flux flattening being in the central region of the reactor core. The present design of adjusters consists of stainless steel tube. The adjuster rods are grouped into 8 banks for movement. Since adjusters are normally fully inserted during reactor operation, they are best suited for production of cobalt 60. The nickel-plated cobalt in the form of either slugs or pellet are used for the design of cobalt pencils. The number of pencils can be varied to optimize the reactivity load and cobalt 60 production requirement. The worth and activity of cobalt adjusters have been worked out considering different pin configuration for the adjuster assembly. To start with we have assumed all adjusters throughout its length are of the same configuration. The flux depression factors within the cobalt pencils have been considered in the estimations of the specific and total cobalt 60 activities. The option of using graded cobalt adjusters, where different pin configuration along the length is considered for better flux flattening

Concentration factors of radionuclides in the marine organisms

International Nuclear Information System (INIS)

1996-03-01

Parameters related to the bioconcentration of radionuclides in the marine were shown by 'Assessment and guideline to the target value of dose in the environment of the power light water reactor facilities' (Nuclear Safety Commission), but the guideline data did not contain Ru and Ce relating to the reprocessing plant. So that more new data than these of 'Technical Reports Series No. 247' (published by IAEA in 1985) were mainly collected. Especially the data of nuclides with poor data of concentration factors (CF) and natural radionuclides (Po-210, Pb-210) were gathered. These data were pigeonholed and many tables (element, kinds of organisms, experimental methods) were made by separating the general remarks from the original experimental reports. The contents of this report are given as under, history of concentration factor (CF), determination method of CF, CF calculation method, calculation models related to CF, tables of metabolic parameters, tables of CF, the present conditions of studies for uptake of radionuclides with long half-life into the marine organisms, CF abstract tables and trial calculation of human exposure by eating the marine organisms. (S.Y.)

Determination of distribution coefficients for 134 Cs, 60 Co and 234 Th radionuclides in Pinheiro river sediment

International Nuclear Information System (INIS)

Lima, M.F.

1992-01-01

The distribution coefficients (K α) were determined in order to foresee the fate of the radionuclides discharged to the environment. Based upon the source-term released by IPEN's facilities in Pinheiros River during the year of 1988, three radionuclides were chosen as being the more critical, according to the radiation protection standards: 137 Cs, 60 Co and 232 Th. Their K α were determined experimentally in laboratory by using the corresponding radioactive tracers 134 Cs, 60 Co and 234 Th. Three different experimental methodologies were used: the static method, the shaken method and the dynamic method. The parameters studied were the effects of pH, aerobic condition and time of contact. The results obtained experimentally for the Kds confirm the predictions that: the cesium is slowly retained by the sediment along the Pinheiros River, the cobalt is an unstable element, therefore its retention by the sediment is affected by variations in the pH values, and finally, the thorium is almost completely retained in the vicinity of the discharge point. (author)

Investigations on bioaccumulation of cobalt by fish eggs

International Nuclear Information System (INIS)

Harms, U.; Behringer, H.; Kunze, J.

1978-01-01

In ionized form cobalt is taken up by fish eggs directly from the water. Accumulation takes place on the chorion where the metal ions are reversibly bound to functional groups of the protein of the envelope of the egg or of the mycosa. To a small extent there occurs a transport of metal ions into the interior of the egg. It could not be clarified within the scope of the studies performed if this process is to be attributed to diffusion. Binding of the cobalt ions to the chorion leads, within hours, to a nearly uncharged final state, an apparent equilibrium, whose position is determined by the cobalt ion concentration of the breeding medium. Foreign ions (electrolytes like Ca 2+ ) lead to reduced uptake of cobalt ions, because they compete with the latter for binding places in the egg's envelope. Complex-forming substances (cysteine) result in lower absorption rates, too, the concentration of available cobalt ions in the water being reduced. (orig.) [de

Study on natural radionuclide activities in meat samples consumed in Sao Paulo City, Brazil

International Nuclear Information System (INIS)

Rosa, Mychelle M.L.; Taddei, Maria HelenaT.

2015-01-01

Consumption of food is usually the most important route by which natural and artificial radionuclides can enter the human body. An assessment of radionuclide levels in different foods and diets is therefore important to estimate the intake of these radionuclides by man. The contamination by radionuclides can occur via the food chain (soil, root, plant and animal), with emphasis to the long half-life radionuclides, which can also have their transfer through the animal meat. The inclusion of meat in human nutrition is important because it is an excellent source of high quality protein, nutrient related to construction and cell regeneration. This work aims the determination of natural radionuclides ( 234 U, 235 U, 238 U, 228 Th, 230 Th, 232 Th, 226 Ra, 228 Ra, and 210 Pb) in meat samples. Five groups of samples were analyzed, such as cattle meat (beef), fish, pork, poultry, and processed meat, after radiochemical separation followed by alpha or alpha beta spectrophotometry, and total count quantification. The determination of these radionuclides is very important because they are products of the natural decay series of 238 U and 232 Th, being easily found in meat samples. (author)

Concentration parameters for radionuclides by marine molluscs

International Nuclear Information System (INIS)

Nakahara, Motokazu; Makamura, Ryoichi; Suzuki, Yuzuru; Matsuba, Mitsue

1994-01-01

Accumulation of radionuclides from seawater and from food by marine molluscs was observed in the laboratory experiments to get bioconcentration parameters for the nuclides. The radionuclides investigated were 57 Co, 95m Tc, 103 Ru, 137 Cs, 65 Zn and 54 Mn. Several species of molluscs containing pelecypods, gastropods and cephalopod were used for the experimental organisms. For the uptake experiment from seawater, the organisms were kept for more than seven days in radioactive seawater containing those radionuclides together. Then the organisms were transferred into nonradioactive seawater to observe the loss of the nuclides from the organisms. Biphasic loss curves were observed for all of the nuclides. Bioconcentration parameters, such as uptake rate, excretion rate, biological half-life and concentration factor at steady state were estimated from the uptake and excretion curves of the nuclides by the organisms by applying an exponential model. In the uptake experiments from radioactive food, the phytoplankton (Tetraselmis tetrathele), the brown algae (Eisenia bicyclis) and the viscera of abalone (Haliotis discus) were fed to bivalves, herbivorous gastropods and carnivorous molluscs, respectively. After single feeding of the labelled food with the nuclides, retention of the nuclides in whole body of the organisms was followed for several weeks or more. The organisms showed relatively high retention of the nuclides in whole body, except 137 Cs and 54 Mn. Retention of 137 Cs and 54 Mn in the organisms one day after feeding of radioactive food was lower than 25% of the radioactivity dosed. (author)

Measurement for cobalt target activity and its axial distribution

International Nuclear Information System (INIS)

Li Xingyuan; Chen Zigen.

1985-01-01

Cobalt target activity and its axial distribution are measured in process of producing radioactive isotopes 60 Co by irradiation in HFETR. Cobalt target activity is obtained with measured data at 3.60 m and 4.60 m, relative axial distribution of cobalt target activity is obtained with one at 30 cm, and axial distribution of cobalt target activity(or specific activity) is obtained with both of data. The difference between this specific activity and measured result for 60 Co teletherapy sources in the end is less than +- 5%

21 CFR 73.3110a - Chromium-cobalt-aluminum oxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Chromium-cobalt-aluminum oxide. 73.3110a Section... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3110a Chromium-cobalt-aluminum oxide. (a) Identity. The color additive chromium-cobalt-aluminum oxide (Pigment Blue 36) (CAS Reg. No...

Speciation analysis of radionuclides

International Nuclear Information System (INIS)

Salbu, B.

2010-01-01

Full text: Naturally occurring and artificially produced radionuclides in the environment can be present in different physico-chemical forms (i. e. radionuclide species) varying in size (nominal molecular mass), charge properties and valence, oxidation state, structure and morphology, density, complexing ability etc. Low molecular mass (LMM) species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as colloids, polymers, pseudocolloids and particles are considered inert. Due to time dependent transformation processes such as mobilization of radionuclide species from solid phases or interactions of mobile and reactive radionuclide species with components in soils and sediments, however, the original distribution of radionuclides deposited in ecosystems will change over time and influence the ecosystem behaviour. To assess the environmental impact from radionuclide contamination, information on radionuclide species deposited, interactions within affected ecosystems and the time-dependent distribution of radionuclide species influencing mobility and biological uptake is essential. The development of speciation techniques to characterize radionuclide species in waters, soils and sediments should therefore be essential for improving the prediction power of impact and risk assessment models. The present paper reviews fractionation techniques which should be utilised for radionuclide speciation purposes. (author)

Evaluation of uncertainties in irradiated hardware characterization: Final report, September 30, 1986-March 31, 1987

International Nuclear Information System (INIS)

Bedore, N.; Levin, A.; Tuite, P.

1987-10-01

Waste Management Group, Inc. has evaluated the techniques used by industry to characterize and classify irradiated hardware components for disposal. This report describes the current practices used to characterize the radionuclide content of hardware components, identifies the uncertainties associated with the techniques and practices considered, and recommends areas for improvement which could reduce uncertainty. Industry uses two different characterization methods. The first uses a combination of gamma scanning, direct sampling, underwater radiation profiling and radiochemical analysis to determine radionuclide content, while the second uses a form of activation analysis in conjunction with underwater radiation profiling. Both methods employ the determination of Cobalt 60 content, and the determination of scaling factors for hard-to-detect Part 61 radionuclides. The accurate determination of Cobalt-60 is critical since the Part 61 activation product radionuclides which affect Part 61 classification are scaled from Cobalt-60. Current uncertainties in Cobalt-60 determination can be reduced by improving underwater radiation profiling equipment and techniques. The calculational techniques used for activation analysis can also be refined to reduce the uncertainties with Cobalt-60 determination. 33 refs., 11 figs., 10 tabs

Characterization and Catalytic Activity of Montmorillonite K10-Supported Cobalt Catalysts

International Nuclear Information System (INIS)

Gobara, H.M.; Ghattas, M.S.; Henien, S.A.

2010-01-01

Montmorillonite K10-supported cobalt catalysts were prepared by wet impregnation method. The samples were analyzed by XRD, TPR, FTTR and BET characterization techniques. [Three phases of cobalt species were identified namely, cobalt oxide (Co 3 O 4 ), cobalt silicate (Co 2 S 1 O 4 ) and cobalt aluminate (CoAl 2 O 4 ). These species were most probably existing within the inter lamellar spaces of the meso porous montmorillonite K10 support]. The two bands observed at 1385 and 760 cm 1 were characteristic of metal species rather than the support, being mostly of Co - O bond vibration. The hysteresis loop, pore size distribution, pore volume and BET surface area were greatly affected by cobalt loading. The catalyst containing 18 wt% cobalt was the most selective sample for ethylene production from ethanol dehydration.

Cobalt separation present in aqueous solution using shell tamarind as bio sorbent

International Nuclear Information System (INIS)

Hernandez L, J.

2014-01-01

In this work a new carbonaceous material is presented with improved adsorption properties obtained by a heart treatment about 5 min from the shell tamarind. It was found that the samples obtained carbonaceous adsorbents are effective in removing Co 2+ (41 mg / g) ions in aqueous solutions. These samples were prepared from tamarind shell, urea, ammonium nitrate and water. The solution was subjected to a combustion process at different temperatures. Carbonaceous samples prepared in this manner were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy (Sem) and surface area measurements by Physisorption of N 2 . Changes in structure, morphology and texture were studied. The results show that this material is of great importance to the applications of adsorption of metal ions. The measurements of specific surface area (Bet) were 2.35 to 203.76 m 2 g -1 with pore diameters between 2.31 and 15.63 nm, indicating that the samples obtained are predominantly meso porous. The combustion process of the solution proved to be advantageous to improve the textural properties of the tamarind shell. The obtained carbonaceous material plays an important role in adsorption to remove cobalt in aqueous solutions. (Author)

A PSMA Ligand Labeled with Cobalt-55 for PET Imaging of Prostate Cancer

DEFF Research Database (Denmark)

Dam, Johan Hygum; Olsen, Birgitte Brinkmann; Baun, Christina

2017-01-01

PURPOSE: Prostate-specific membrane antigen (PSMA) comprises a recognized target for molecular imaging of prostate cancer. As such, radiolabeled PSMA inhibitors are of great value for diagnosis and staging of this disease. Herein, we disclose the preclinical characterization of [(55)Co]PSMA-617...... for positron emission tomography (PET)/x-ray computed tomography (CT) imaging of prostate cancer lesions. PROCEDURES: By the application of microwave heating, PSMA-617 in acetate buffer (0.4 M, pH 4.4) was labeled with the radioisotopes cobalt-55/57. The extents of internalization and dissociation constants (K...... to the biodistribution in LNCaP xenograft mice, [(57)Co]PSMA-617 displayed a high and relatively constant uptake in the tumor (12.9 %IA/g at 1 h to 10.5 %IA/g at 24 h) with an initial but transient high uptake in the kidneys, adrenals, and spleen. Tumor-to-background ratios improved over time as normal tissue cleared...

Radiation induced ligand loss from cobalt complexes

International Nuclear Information System (INIS)

Funston, A. M.; McFadyen, W.D.; Tregloan, P.A.

2000-01-01

Full text: Due to the rapid nature of ligand dissociation from cobalt(II) complexes the study of the rate of ligand dissociation necessitates the use of a technique such as pulse radiolysis. This allows the rapid reduction of the corresponding cobalt(III) complex by a reducing radical, such as the aquated electron, to form the cobalt(II) complex. However, to date, no systematic study of either the mechanism of reduction or the influence of the electronic structure on the rate of ligand dissociation has been carried out. In order to understand these processes more fully the mechanism of reduction of a range of related cobalt(III) complexes by the aquated electron and the subsequent rate of ligand dissociation from the resulting cobalt(II) complexes is being investigated. It has been found that a number of processes are observed following the initial rapid reaction of the cobalt(III) complex with the aquated electron. Ultimately ligand loss is observed. Depending upon the complex, the initial processes observed may include the formation of coordinated radicals and electron transfer within the complex. For complexes containing aromatic ligands such as 2,2'-bipyridine, 1,10-phenanthroline and dipyrido[3,2-a:2',3'-c]phenazine the formation of a coordinated radical is observed as the initial reduction step. The kinetics of ligand dissociation of these complexes has been determined. The loss of monodentate ligands is fast and has been indistinguishable from the reduction processes when aromatic ligands are also present in the complex. However, for diamine chelates and diimine chelates spectra of the transient species can be resolved

Polymer tribology by combining ion implantation and radionuclide tracing

International Nuclear Information System (INIS)

Timmers, Heiko; Gladkis, Laura G.; Warner, Jacob A.; Byrne, Aidan P.; Grosso, Mariela F. del; Arbeitman, Claudia R.; Garcia-Bermudez, Gerardo; Geruschke, Thomas; Vianden, Reiner

2010-01-01

Radionuclide tracers were ion implanted with three different techniques into the ultra-high molecular weight polyethylene polymer. Tracer nuclei of 7 Be were produced with inverse kinematics via the reaction p( 7 Li, 7 Be)n and caught by polymer samples at a forward scattering angle with a maximum implantation energy of 16 MeV. For the first time, 97 Ru, 100 Pd, and, independently, 111 In have been used as radionuclide tracers in ultra-high molecular weight polyethylene. 97 Ru and 100 Pd were recoil-implanted following the fusion evaporation reactions 92 Zr( 12 C,α3n) 97 Ru and 92 Zr( 12 C,4n) 100 Pd with a maximum implantation energy of 8 MeV. 111 In ions were produced in an ion source, mass-separated and implanted at 160 keV. The tribology of implanted polymer samples was studied by tracing the radionuclide during mechanical wear. Uni-directional and bi-directional sliding apparatus with stainless steel actuators were used. Results suggest a debris exchange process as the characteristic feature of the wear-in phase. This process can establish the steady state required for a subsequently constant wear rate in agreement with Archard's equation. The nano-scale implantation of mass-separated 111 In appears best suited to the study of non-linear tribological processes during wear-in. Such non-linear processes may be expected to be important in micro- and nanomachines.

The cobalt-60 container scanner

International Nuclear Information System (INIS)

Jigang, A.; Liye, Z.; Yisi, L.; Haifeng, W.; Zhifang, W.; Liqiang, W.; Yuanshi, Z.; Xincheng, X.; Furong, L.; Baozeng, G.; Chunfa, S.

1997-01-01

The Institute of Nuclear Energy Technology (INET) has successfully designed and constructed a container (cargo) scanner, which uses cobalt-60 of 100-300 Ci as radiation source. The following performances of the Cobalt-60 container scanner have been achieved at INET: a) IQI (Image Quality Indicator) - 2.5% behind 100 mm of steel; b) CI (Contrast Indicator) - 0.7% behind 100 mm of steel; c) SP (Steel Penetration) - 240 mm of steel; d) Maximum Dose per Scanning - 0.02mGy; e) Throughput - twenty 40-foot containers per hour. These performances are equal or similar to those of the accelerator scanners. Besides these nice enough inspection properties, the Cobalt-60 scanner possesses many other special features which are better than accelerator scanners: a) cheap price - it will be only or two tenths of the accelerator scanner's; b) low radiation intensity - the radiation protection problem is much easier to solve and a lot of money can be saved on the radiation shielding building; c) much smaller area for installation and operation; d) simple operation and convenient maintenance; e) high reliability and stability. The Cobalt-60 container (or cargo) scanner is satisfied for boundary customs, seaports, airports and railway stations etc. Because of the nice special features said above, it is more suitable to be applied widely. Its high properties and low price will make it have much better application prospects

Radionuclide composition in the surface layer of particles in the troposphere and stratosphere falls

International Nuclear Information System (INIS)

Prokof'ev, O.N.

1977-01-01

Radionuclide content in troposphere and stratosphere fall-outs as well as radionuclide washing-off from fall-out particle; are important to determine internal irradiation doses received by separate critical organs of human body. In surface-contaminated products (floury products of grain contaminated while in ears, vegetables, fruits, berries, noncovered or insufficiently covered products during fall-outs) radionuclides initially (in an initial state) are connected with fall-out particles. Radionuclides in biologically contaminated products (milk, meat etc.) are not connected with the particles and have the assimilable form. However, the degree of radionuclide transition from forage (grasses, hay etc.) surface-contaminated as a results of fall-outs into animal produce (milk, meat etc.) also depends on radionuclide washing-off from fall-out particles, which in the latter results from the formation nature and a kind of particles of the main substance. Radionuclide washing-off degree (and, consequently, biological availability) by glazed silicate particles is caused by radionuclide distribution between particle volume and surface in an appropriate sample. According to Israel Yu.A. method calculated were the shares of surface-bound atoms for all the particle totality in an explosion cloud for mass chains, which composition includes biologically important radionuclides. Particle solidification time is taken to equal 7 and 40s. Independent yields of chain radionuclides and its total yield are taken for 228 U fission under 14 MeV neutron effect. The calculation results are presented in the tables

High-solid mesophilic methane fermentation of food waste with an emphasis on Iron, Cobalt, and Nickel requirements.

Science.gov (United States)

Qiang, Hong; Lang, Dong-Li; Li, Yu-You

2012-01-01

The effect of trace metals on the mesophilic methane fermentation of high-solid food waste was investigated using both batch and continuous experiments. The continuous experiment was conducted by using a CSTR-type reactor with three run. During the first run, the HRT of the reactor was stepwise decreased from 100 days to 30 days. From operation day 50, the reactor efficiency deteriorated due to the lack of trace metals. The batch experiment showed that iron, cobalt, and nickel combinations had a significant effect on food waste. According to the results of the batch experiment, a combination of iron, cobalt, and nickel was added into the CSTR reactor by two different methods at run II, and III. Based on experimental results and theoretical calculations, the most suitable values of Fe/COD, Co/COD, and Ni/COD in the substrate were identified as 200, 6.0, and 5.7 mg/kg COD, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

Highly selective cobalt-catalyzed hydrovinylation of styrene

NARCIS (Netherlands)

Grutters, M.M.P.; Müller, C.; Vogt, D.

2006-01-01

The hydrovinylation reaction is a codimerization of a 1,3-diene or vinyl arene and ethene with great potential for fine chemicals and pharmaceuticals. For the first time, enantioselective cobalt-catalyzed hydrovinylations of styrene were achieved with a cobalt-based system bearing a chiral

Cobalt Blues The Story of Leonard Grimmett, the Man Behind the First Cobalt-60 Unit in the United States

CERN Document Server

Almond, Peter R

2013-01-01

For the latter half of the 20th century, cobalt-60 units were the mainstay of radiation treatments for cancer. Cobalt Blues describes the development of the first cobalt-60 unit in the United States and the man behind it, Leonard Grimmett. Conceptually conceived before World War II, it only became possible because of the development of nuclear reactors during the war. Although Grimmett conceived of and published his ideas first, the Canadians built the first units because of the capability of their reactor to produce more suitable cobalt-60 sources. This book tells the story of how Grimmett and others came together at the time that the U S Atomic Energy Agency was pushing the use of radioactivity in medicine. Due to his sudden death, very little information about Grimmett was known until recently, when various documents have come to light, allowing the full story to be told.

Production of 57Co, 109Cd, 111In and 117mSn using CV-28 cyclotron at IPEN-CNEN/SP

International Nuclear Information System (INIS)

Osso, J.A. Jr.; Landini, L.; Lion, L.F.; Moraes, V.

2001-01-01

222MBq (6mCi) of 57 Co and impurity levels of 1.13 and 1.29% for 56 Co and 58 Co, respectively, at delivery time. In order to achieve these results, a chemical separation method was developed with a separation yield of 93% for 5 '7Co and a negligible loss of Ni. A composite target of Ni and Ag was prepared and a chemical separation method proposed to allow the separation between the targets and the products of interest, 57 Co and 109 Cd. The yields obtained in the irradiation of the composite target were: 947.94kBq/μA.h (25.62μCi/μA.h) of 57 Co - direct reaction, 259-00kBq/μA.h (7μCi/μA.h) of 57 Co - indirect reaction (11.31 days after EOB) and 71.41kBq/μA.h (1.93μCi/μA.h) of 109 Cd, which showed the efficiency of its use, as well as the chemical separation, with a yield of 80% for 57 Co and 109 Cd. 111 ln (t 1/2 =67.5 h) has appropriate characteristics for Diagnosis in Nuclear Medicine due to its decay mode (100% by electron capture) and its adequate half-life to slow biological studies, that makes it one of radioisotopes of interest of Brazilian Physicians. It can also be used in angular correlation studies in Nuclear Physics. 111 In was produced by the 112 Cd(p,2n) 111 ln reaction, that has the highest yield. The Cd targets were prepared by electroplating of CdSO 4 solution in copper and copper/nickel backings. After being irradiated, a chemical separation was performed by an acetic acid extraction method, with an overall recovery yield for 111 ln higher than 95%. The level of the chemical impurities of Cd, Ni and Cu were bellow than the permissible values. 117m Sn (t 1/2 =14 d) has suitable characteristics of decay to be used as a tracer of SnCl 2 in the labeling of organic molecules with 99m Tc and also in radiotherapeutical applications. It was prepared by the irradiation of natural tin through the nuclear reactions nat Sn(p,xn) 117 Sb→ 117m Sn. The production thick target yield of 117m Snnn was 784.4kBq/μA.h (21.20μCi/μA.h) and with the proper

SEPARATION OF METAL SALTS BY ADSORPTION

Science.gov (United States)

Gruen, D.M.

1959-01-20

It has been found that certain metal salts, particularly the halides of iron, cobalt, nickel, and the actinide metals, arc readily absorbed on aluminum oxide, while certain other salts, particularly rare earth metal halides, are not so absorbed. Use is made of this discovery to separate uranium from the rare earths. The metal salts are first dissolved in a molten mixture of alkali metal nitrates, e.g., the eutectic mixture of lithium nitrate and potassium nitrate, and then the molten salt solution is contacted with alumina, either by slurrying or by passing the salt solution through an absorption tower. The process is particularly valuable for the separation of actinides from lanthanum-group rare earths.

Technique for radionuclide composition analysis of snow cover in the Chernobyl' NPP 30-km zone using fiber sorbents

International Nuclear Information System (INIS)

Kham'yanov, L.P.; Rau, D.F.; Amosov, M.M.; Strel'nikova, A.E.; Tereshchenko, V.I.; Veber, T.S.

1989-01-01

The high-sensitivity, simple and fast technique for analysis of large-dispersive and ionic components of snow cover radioactivity is suggested. It is based on separation of a sample by fractions, concentration of the dispersive fraction on mechanical filters and the dissolved one on ion-exchange sorbents and separated fraction spectrometry. The minimum measured contamination level is 3.7 Bq/dm 3 for each radionuclide analyzed. The conclusion is made that the technique suggested is the reliable method for radionuclide content analysis is snow cover samples of the Chernobyl' NPP zone. 1 tab

Sputtering on cobalt with noble gas ions

International Nuclear Information System (INIS)

Sarholt-Kristensen, L.; Johansen, A.; Johnson, E.

1983-01-01

Single crystals of cobalt have been bombarded with 80 keV Ar + ions and with 80 keV and 200 keV Xe + ions in the [0001] direction of the hcp phase and the [111] direction of the fcc phase. The sputtering yield has been measured as function of target temperature (20 0 C-500 0 C), showing a reduction in sputtering yield for 80 keV Ar + ions and 200 keV Xe + ions, when the crystal structure changes from hcp to fcc. In contrast to this, bombardment with 80 keV Xe + ions results in an increase in sputtering yield as the phase transition is passed. Sputtering yields for [111] nickel are in agreement with the sputtering yields for fcc cobalt indicating normal behaviour of the fcc cobalt phase. The higher sputtering yield of [0001] cobalt for certain combinations of ion mass and energy may then be ascribed to disorder induced partly by martensitic phase transformation, partly by radiation damage. (orig.)

3. Production of radionuclides, preparation and handling of labelled compounds

International Nuclear Information System (INIS)

Toelgyessy, J.

1981-01-01

The preparation of natural radioactive compounds and the manufacture of artificial radionuclides, the labelling of organic compounds, and the methods of radioactive substance separation are described. The principles are shown of handling radioactive materials and a brief description is given of the stability, packaging and storage of radiopharmaceuticals. (J.P.)

Determination of radionuclides in discharged water from gold ...

African Journals Online (AJOL)

Long-lived radionuclides from the Uranium-, Thorium- and Actinium-decay chains in the discharged water into the environment were radiochemically separated and the activity concentrations determined for 238U-series ranged from 3.8 ± 1.5 to 178 ± 19 mBqL-1, 232Th-series ranged from < 2.0 to 47.8 ± 7.3 mBqL-1 and ...

Radionuclide inventories for the F- and H-area seepage basin groundwater plumes

Energy Technology Data Exchange (ETDEWEB)

Hiergesell, Robert A [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Kubilius, Walter P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-05-01

Within the General Separations Areas (GSA) at the Savannah River Site (SRS), significant inventories of radionuclides exist within two major groundwater contamination plumes that are emanating from the F- and H-Area seepage basins. These radionuclides are moving slowly with groundwater migration, albeit more slowly due to interaction with the soil and aquifer matrix material. The purpose of this investigation is to quantify the activity of radionuclides associated with the pore water component of the groundwater plumes. The scope of this effort included evaluation of all groundwater sample analyses obtained from the wells that have been established by the Environmental Compliance & Area Completion Projects (EC&ACP) Department at SRS to monitor groundwater contamination emanating from the F- and H-Area Seepage Basins. Using this data, generalized groundwater plume maps for the radionuclides that occur in elevated concentrations (Am-241, Cm-243/244, Cs-137, I-129, Ni-63, Ra-226/228, Sr-90, Tc-99, U-233/234, U-235 and U-238) were generated and utilized to calculate both the volume of contaminated groundwater and the representative concentration of each radionuclide associated with different plume concentration zones.

Inorganic ion-exchangers. Their role in chromatographic radionuclide generators for the decade 1993-2002

International Nuclear Information System (INIS)

Mushtaq, A.

2004-01-01

Ion-exchangers are found not only in water purification processes, the original major application, but also in analytical chemistry for the separation and isolation of elements, hydrometallurgy, inorganic chemistry and biochemistry, in food technology, and of course in many specialized fields related to the utilization of atomic energy. The use of organic ion-exchangers is limited by virtue of their limited stability under harsh conditions, whereas inorganic ion-exchangers possess important properties, which make them very useful for chemical separation and purification in intense radiation fields. The availability of short-lived radionuclides from radionuclide generators provides an inexpensive and convenient alternative to in-house radioisotope production facilities such as accelerators and cyclotrons. Due to their simplicity of operation, chromatographic based generators have been the method of choice, although generators based on solvent extraction and on volatilization and sublimation have also been developed, and are routinely used. In this paper use of inorganic ion-exchangers for the development of radionuclide generators for the decade 1993-2002 has been compiled. (author)

Monitoring of Radio-nuclides in the Vicinities of Finnish Nuclear Power Plants in 2002-2004

International Nuclear Information System (INIS)

Ilus, E.; Klemola, S.; Vartti, V.-P.; Mattila, J.; Ikaeheimonen, T.K.

2000-03-01

The monitoring of radioactive substances round Finnish nuclear power plants continued in 2002-2004 in accordance with the regular environmental monitoring programmes. Altogether, some 1000 samples are analysed annually from the terrestrial and aquatic environs of the two power plants. Trace amounts of activation products originating from airborne releases from the local power plants were detected in several air and deposition samples taken from the close vicinities of the power plants. At Loviisa, observations were made in two; at Olkiluoto in three aerosol samples during the reporting period. Except for the naturally occurring beryllium-7, the concentrations of all radionuclides in the air samples were very low; from few microbequerels to few tens of microbequerels per cubic metre. A similar pattern was tenable for the deposition samples as well. The activity concentrations of cobalt-60 of local origin were at their highest 0.3 bequerels per square metre in one sample taken from Loviisa and in one sample taken from Olkiluoto. No traces of local discharge nuclides were detected in foodstuffs, drinking water or garden products. In mushrooms and wild berries picked up in 2004 from the Loviisa area, only Chernobyl-derived caesium isotopes and natural potassium-40 were detected. Local discharge nuclides were more abundant in the aquatic environment, especially in samples of indicator organisms, sinking matter and sediments, which effectively accumulate radioactive substances. Besides tritium originating from local discharges, the most significant artificial radionuclide in the samples taken from the aquatic environs of the power plants was still caesium-137 originating from the Chernobyl accident (potassium-40 is a naturally occurring radionuclide). Elevated tritium concentrations were more frequent in the water samples from Loviisa. In indicator organisms and sinking matter, the observed concentrations of local discharge nuclides were generally somewhat higher and

Development of a mechanistic model for release of radionuclides from spent fuel in brines: Salt Repository Project

International Nuclear Information System (INIS)

Reimus, P.W.; Windisch, C.F.

1988-03-01

At present there are no comprehensive mechanistic models describing the release of radionuclides from spent fuel in brine environments. This report provides a comprehensive review of the various factors that can affect radionuclide release from spent fuel, suggests a modeling approach, and discusses proposed experiments for obtaining a better mechanistic understanding of the radionuclide release processes. Factors affecting radionuclide release include the amount, location, and disposition of radionuclides in the fuel and environmental factors such as redox potential, pH, the presence of complexing anions, temperature, and radiolysis. It is concluded that a model describing the release of radionuclides from spent fuel should contain separate terms for release from the gap, grain boundaries, and grains of the fuel. Possible functional forms for these terms are discussed in the report. Experiments for assessing their validity and obtaining key model parameters are proposed. 71 refs., 4 figs., 6 tabs

Study on natural radionuclide activities in meat samples consumed in Sao Paulo City, Brazil

Energy Technology Data Exchange (ETDEWEB)

Rosa, Mychelle M.L.; Taddei, Maria HelenaT. [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Avegliano, Roseane P.; Maihara, Vera A., E-mail: mychelle@cnen.gov.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Consumption of food is usually the most important route by which natural and artificial radionuclides can enter the human body. An assessment of radionuclide levels in different foods and diets is therefore important to estimate the intake of these radionuclides by man. The contamination by radionuclides can occur via the food chain (soil, root, plant and animal), with emphasis to the long half-life radionuclides, which can also have their transfer through the animal meat. The inclusion of meat in human nutrition is important because it is an excellent source of high quality protein, nutrient related to construction and cell regeneration. This work aims the determination of natural radionuclides ({sup 234}U, {sup 235}U, {sup 238}U, {sup 228}Th, {sup 230}Th, {sup 232}Th, {sup 226}Ra, {sup 228}Ra, and {sup 210}Pb) in meat samples. Five groups of samples were analyzed, such as cattle meat (beef), fish, pork, poultry, and processed meat, after radiochemical separation followed by alpha or alpha beta spectrophotometry, and total count quantification. The determination of these radionuclides is very important because they are products of the natural decay series of {sup 238}U and {sup 232}Th, being easily found in meat samples. (author)

A laboratory and field evaluation of the mobility of cobalt-60/EDTA

International Nuclear Information System (INIS)

Jones, T.L.; Gee, G.W.; Kirkham, R.R.; Swanson, J.L.

1983-01-01

We have observed a time and soil type dependence in the ability of the organic complexant EDTA to keep cobalt-60 in solution. Test results indicate that short-term adsorption tests lasting 5 days or less can be misleading. In short-term tests using cobalt-60/EDTA and soil from the Hanford site, low sorption in batch tests and high mobility in column tests were observed. During long-term batch test using cobalt-60/EDTA, the percentage of cobalt remaining in solution decreased from 90% after 7 days to less than 10% after 500 days. In laboratory and field column tests where low water flow rates allowed long contact time, virtually no cobalt movement was observed even though in the field test tritium was transported over 4 meters. Long-term batch tests using cobalt-60/EDTA and soil from Savannah River burial grounds showed that cobalt remainin in solution dropped to 30% of the total cobalt added after 5 days and to less than 1% after 15 days. Batch tests using soil from Oak Ridge burial grounds were less dramatic showing cobalt in solution decreasing from 90% after 5 days to 70% after 35 days. The cobalt-60/EDTA complex appears to be dissociating and leaving uncomplexed cobalt which is readily sorbed. The dissociation seems to be rather complete in Hanford and Savannah River soil but limited in the Oak Ridge soil. The implication to waste management is that the potential for transport of cobalt by EDTA may not be as serious at all burial sites as once thought

Selection of optimum ROI for dual radionuclide analysis of 55Fe-63Ni and 63Ni-60Co

International Nuclear Information System (INIS)

Priya, S.; Prabhath Ravi, K.; Yadav, R.K.B.; Rao, D.D.; Gopalakrishnan, R.K.

2016-01-01

Dual label counting in liquid scintillation counting (LSC) enables simultaneous activity determination of two radionuclides. Dual counting procedure for 3 H and 14 C has been well established. There are several other nuclides like 63 Ni (E β- =67keV), 55 Fe (6 keV X-ray and auger electron) which are often chemically separated using detailed procedures with high decontamination factors (DF) and quantified using LSC. Despite the laborious separations, traces of these nuclides in the chemically separated fractions can mutually make their quantification difficult due to overlap of counts from both radionuclides in the spectrum, which gets further complicated in presence of traces of 60 Co. For dual label counting technique, it is essential to establish the discriminator setting at which there will be spillover of counts from both radionuclides in the two counting regions required for the inclusion method. The objective of the current work is to establish two counting ROI's for dual counting of (i) 63 Ni- 55 Fe and (ii) 63 Ni- 60 Co in a TDCR based LSC system

EXAFS Determination of the Structure of Cobalt in Carbon-Supported Cobalt and Cobalt-Molybdenum Sulfide Hydrodesulfurization Catalysts.

NARCIS (Netherlands)

Koningsberger, D.C.; Bouwens, S.M.A.M.; Veen, J.A.R. van; Beer, V.H.J. de; Prins, R.

1991-01-01

The structure of the cobalt present in carbon-supported Co and Co-Mo sulfide catalysts was studied by means of X-ray absorption spectroscopy at the Co K-edge and by X-ray photoelectron spectroscopy (XPS). Thiophene hydrodesulfurization activities were used to measure the catalytic properties of

A spot test for detection of cobalt release - early experience and findings

DEFF Research Database (Denmark)

Thyssen, Jacob P; Menné, Torkil; Johansen, Jeanne D

2010-01-01

It is often difficult to establish clinical relevance of metal exposure in cobalt-allergic patients. Dermatologists and patients may incorrectly assume that many metallic items release cobalt at levels that may cause cobalt dermatitis. Cobalt-allergic patients may be unaware that they are exposed...

Radionuclide fixation mechanisms in rocks

International Nuclear Information System (INIS)

Nakashima, S.

1991-01-01

In the safety evaluation of the radioactive waste disposal in geological environment, the mass balance equation for radionuclide migration is given. The sorption of radionuclides by geological formations is conventionally represented by the retardation of the radionuclides as compared with water movement. In order to quantify the sorption of radionuclides by rocks and sediments, the distribution ratio is used. In order to study quantitatively the long term behavior of waste radionuclides in geological environment, besides the distribution ratio concept in short term, slower radionuclide retention reaction involving mineral transformation should be considered. The development of microspectroscopic method for long term reaction path modeling, the behavior of iron during granite and water interaction, the reduction precipitation of radionuclides, radionuclide migration pathways, and the representative scheme of radionuclide migration and fixation in rocks are discussed. (K.I.)

Elucidating key factors affecting radionuclide aging in soils

Energy Technology Data Exchange (ETDEWEB)

Roig, M. [Universitat Politecnica Catalunya, Institut de Tecniques Energetiques, Barcelona (Spain); Rigola, A.; Vidal, M.; Rauret, G. [Barcelona Univ., Dept. de Quimica Analitica (Spain)

2004-07-01

Mechanistic studies allow at present to describe the processes governing the short-term interaction of radiostrontium and radiocaesium in soils. The initial sorption step can be described through the estimation of the soil-soil solution distribution coefficient from soil parameters, as cationic exchange capacity, radiocaesium interception potential and concentration of competing ions in the soil solution. After the initial soil-radionuclide interaction, a fraction of radionuclide is no longer available for exchange with the solution, and it remains fixed in the solid fraction. At present, the initial fixed fraction of a radionuclide in a given soil cannot be predicted from soil properties. Besides, little is known about soil and environmental factors (e.g., temperature; hydric regime) provoking the increase in the fixed fraction with time, the so-called aging process. This process is considered to control the reduction of food contamination with time at contaminated scenarios. Therefore, it is crucial to be able to predict the radionuclide aging in the medium and long term for a better risk assessment, especially when a decision has to be made between relying on natural attenuation versus implementing intervention actions. Here we study radiostrontium and radiocaesium aging in a set of soils, covering a wide range of soil types of contrasting properties (e.g., loamy calcareous; podzol; chernozem, organic). Three factors are separately and simultaneously tested: time elapsed since contamination, temperature and hydric regime. Changes in the radionuclide fixed fraction are estimated with a leaching test based on the use of a mild extractant solution. In addition to this, secondary effects on the radiocaesium interception potential in various soils are also considered. (author)

Transport of radionuclides by concentrated brine in a porous medium with micropore-macropore structure

International Nuclear Information System (INIS)

Hassanizadeh, S.M.

1987-01-01

This work concerns itself with the study of effects of soil aggregation and high salt concentrations on the transport of radionuclides by concentrated brine flowing through an aggregated porous medium. The medium is considered to be composed of porous rock aggregates separated by macropores through which the brine flows and transport of salt and radionuclides takes place. The aggregates contain dead-end pores, cracks, and stationary pockets collectively called micropores. The micropore space does not contribute to the flow, but it serves as a storage for salt and radionuclides. Adsorption of radionuclides takes place at internal surfaces of aggregates where they assume that a linear equilibrium isotherm describes the process. A one-dimensional numerical model is developed which is based on two sets of equations: one set for the flow and transport of salt and another set for transport of radionuclides. Results of numerical experiments clearly indicate that the existence of high salt concentrations markedly reduces the peak of nuclides concentration and slows down their movement. Also, it is found that diffusive mass exchange between macropores and aggregates results in a pronounced lowering of the radionuclides concentration peaks. 9 references, 7 figures

Determination of natural radionuclides in lichen samples of Carnoparmelia Texana

International Nuclear Information System (INIS)

Alencar, Marcos M.; Damatto, Sandra R.; Mazzilli, Barbara P.

2009-01-01

Lichen plays an important role in studies of environmental pollution. It can be used for the evaluation of air contaminants, including heavy metals and radionuclides. The main objective of this study is to verify the possibility of using the lichen species Canoparmelia Texana for the assessment of natural radionuclides of the U and Th decay series in air in the vicinity of Instituto de Pesquisas Energeticas e Nucleares (IPEN) installations. IPEN has as major activity to perform research in the field of the nuclear fuel cycle, and therefore deals with natural radionuclides of the U and Th series. The content of 238 U, 234 U, 230 Th, 210 Po and 232 Th in lichen samples were determined by alpha spectrometry after a radiochemical separation. Ra isotopes and 210 Pb were determined by gross alpha and beta counting after a radiochemical separation and measurement on a low background gas flow proportional detector. The results obtained for 238 U varied from 2.4 ± 0.4 Bq kg -1 to 6.6 ± 0.1 Bq kg -1 and from 4.4 ± 0.3 Bq kg -1 to 12.1 ± 2.6 Bq kg -1 , for 232 Th. For 226 Ra varied from 13 ± 1 Bq kg -1 to 38 ± 2 Bq kg -1 and from 200 ± 13 Bq kg -1 to 351 ± 12 Bqkg -1 for 228 Ra. The results obtained were compared with data obtained for the same radionuclides in lichen samples in an area affected by TENORM industry and can be considered as background for this lichen species. It can be concluded that the control of atmospheric discharges of IPEN facilities has been effective along the years, giving no evidence of radiological environmental impact. (author)

Incentives and opportunities for reducing the cobalt content in reactor core components

International Nuclear Information System (INIS)

Ocken, H.

1985-01-01

Cobalt in core components contributes to radiation field buildup on out-of-core surfaces. Core components containing cobalt-base alloys and cobalt as an impurity are identified. The use of cobalt-free wear-resistant alloys and construction materials with lower impurity levels of cobalt is disused. It is argued that such measures are cost effective. Lower radiation fields and disposal costs will offset higher raw material costs. Component performance will not be affected. (author)

The determination of long life radionuclides by means of sector field ICP mass spectrometry

International Nuclear Information System (INIS)

Kerl, W.; Becker, J.S.; Dietze, H.J.; Dannecker, W.

1996-01-01

Different analytical processes for determining long life radionuclides by means of double-focussing sector field ICP mass spectrometry are described. In determining long life radionuclides by means of ICP-MS, on the one hand the analytical problem areas are in the interference of isobaric atom or molecule ions (eg: 151 Eu + - 151 Sm + , 79 Se + - 39 Ar 40 ArH + ) and on the other hand in the high detection limits when using commercial sample introduction systems (eg: For 129 I). An online coupling of HPLC and ICP-MS was built up for the separation of isobaric atom ions and was tested for the separation of isobaric atom ions and was tested for its efficiency in the separation of lanthanides. Special sample introduction systems for ICP-MS were developed for the analysis of 129 I, by which the sensitivity of detection can be appreciably improved compared to commercial sample introduction systems. (orig.) [de

Marine biogeochemistry of radionuclides

International Nuclear Information System (INIS)

Fowler, S.W.

1997-01-01

Radionuclides entering the ocean from runoff, fallout, or deliberate release rapidly become involved in marine biogeochemical cycles. Sources, sinks and transport of radionuclides and analogue elements are discussed with emphasis placed on how these elements interact with marine organisms. Water, food and sediments are the source terms from which marine biota acquire radionuclides. Uptake from water occurs by surface adsorption, absorption across body surfaces, or a combination of both. Radionuclides ingested with food are either assimilated into tissue or excreted. The relative importance of the food and water pathway in uptake varies with the radionuclide and the conditions under which exposure occurs. Evidence suggests that, compared to the water and food pathways, bioavailability of sediment-bound radionuclides is low. Bioaccumulation processes are controlled by many environmental and intrinsic factors including exposure time, physical-chemical form of the radionuclide, salinity, temperature, competitive effects with other elements, organism size, physiology, life cycle and feeding habits. Once accumulated, radionuclides are transported actively by vertical and horizontal movements of organisms and passively by release of biogenic products, e.g., soluble excreta, feces, molts and eggs. Through feeding activities, particles containing radionuclides are ''packaged'' into larger aggregates which are redistributed upon release. Most radionuclides are not irreversibly bound to such particles but are remineralized as they sink and/or decompose. In the pelagic zones, sinking aggregates can further scavenge particle-reactive elements thus removing them from the surface layers and transporting them to depth. Evidence from both radiotracer experiments and in situ sediment trap studies is presented which illustrates the importance of biological scavenging in controlling the distribution of radionuclides in the water column. (author)

Removal of Cobalt Ion by Adsorbing Colloidal Flotation

Energy Technology Data Exchange (ETDEWEB)

Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

1998-09-30

Simulated waste liquid containing 50 ppm cobalt ion was treated by adsorbing colloidal flotation using Fe(III) or Al(III) as flocculant and a sodium lauryl sulfate as a collector. Parameters such as pH, surfactant concentration, Fe(III) or Al(III) concentration, gas flow rate, etc., were considered. The flotation with Fe(III) showed 99.8% removal efficiency of cobalt on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, and flotation time 30 min. When the waste solution was treated with 35% H{sub 2}O{sub 2} prior to adsorbing colloidal flotation, the optimal pH for removing cobalt shifted to weak alkaline range and flotation could be applied in wider range of pH as compared to non-use of H{sub 2}O{sub 2}. Additional use of 20 ppm Al(III) after precipitation of 50 ppm Co(II) with 50 ppm Fe(III) made the optimal pH range for preferable flotation wider. Foreign ions such as, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, Ca{sup 2+} were adopted and their effects were observed, Of which sulfate ion was found to be detrimental to removal of cobalt ion by flotation. Coprecipitation of Co ion with Fe(III) and Al(III) resulted in better removal efficiency of cobalt ion in the presence of sulfate ion. (author). 14 refs., 13 figs.

Concentration parameters for radionuclides by marine molluscs

Energy Technology Data Exchange (ETDEWEB)

Nakahara, Motokazu; Makamura, Ryoichi; Suzuki, Yuzuru; Matsuba, Mitsue [National Inst. of Radiological Sciences, Nakaminato, Ibaraki (Japan). Nakaminato Lab. Branch Office

1994-03-01

Accumulation of radionuclides from seawater and from food by marine molluscs was observed in the laboratory experiments to get bioconcentration parameters for the nuclides. The radionuclides investigated were {sup 57}Co, {sup 95m}Tc, {sup 103}Ru, {sup 137}Cs, {sup 65}Zn and {sup 54}Mn. Several species of molluscs containing pelecypods, gastropods and cephalopod were used for the experimental organisms. For the uptake experiment from seawater, the organisms were kept for more than seven days in radioactive seawater containing those radionuclides together. Then the organisms were transferred into nonradioactive seawater to observe the loss of the nuclides from the organisms. Biphasic loss curves were observed for all of the nuclides. Bioconcentration parameters, such as uptake rate, excretion rate, biological half-life and concentration factor at steady state were estimated from the uptake and excretion curves of the nuclides by the organisms by applying an exponential model. In the uptake experiments from radioactive food, the phytoplankton (Tetraselmis tetrathele), the brown algae (Eisenia bicyclis) and the viscera of abalone (Haliotis discus) were fed to bivalves, herbivorous gastropods and carnivorous molluscs, respectively. After single feeding of the labelled food with the nuclides, retention of the nuclides in whole body of the organisms was followed for several weeks or more. The organisms showed relatively high retention of the nuclides in whole body, except {sup 137}Cs and {sup 54}Mn. Retention of {sup 137}Cs and {sup 54}Mn in the organisms one day after feeding of radioactive food was lower than 25% of the radioactivity dosed. (author).

Heating analysis of cobalt adjusters in reactor core

International Nuclear Information System (INIS)

Mei Qiliang; Li Kang; Fu Yaru

2011-01-01

In order to produce 60 Co source for industry and medicine applications in CANDU-6 reactor, the stainless steel adjusters were replaced with the cobalt adjusters. The cobalt rod will generate the heat when it is irradiated by neutron and γ ray. In addition, 59 Co will be activated and become 60 Co, the ray released due to 60 Co decay will be absorbed by adjusters, and then the adjusters will also generate the heat. So the heating rate of adjusters to be changed during normal operation must be studied, which will be provided as the input data for analyzing the temperature field of cobalt adjusters and the relative heat load of moderator. MCNP code was used to simulate whole core geometric configuration in detail, including reactor fuel, control rod, adjuster, coolant and moderator, and to analyze the heating rate of the stainless steel adjusters and the cobalt adjusters. The maximum heating rate of different cobalt adjuster based on above results will be provided for the steady thermal hydraulic and accident analysis, and make sure that the reactor is safe on the thermal hydraulic. (authors)

Determination of selenium in samples of concentrated of nickel plus cobalt using the analysis through activation with epi thermic neutron

International Nuclear Information System (INIS)

Capote Rodriguez, G.; Perez Zayas, G.; Hernandez Rivero, A.; Moreno Bermudez, G.; Ribeiro Guevara, S.; Arribere, M.A.; Molina Insfran, J.

1997-01-01

In this work, the concentration of selenium and other elements was determined. Seventeen samples of sulfides plus cobalt were used. Among the employed methods for such purpose, the analysis was made through neutronic activation, in its instrumental variants, and by means of the application of radiochemical separation. (author) [es

The effect of gaseous ammonia on cobalt perrhenate

International Nuclear Information System (INIS)

Maslov, L.P.; Men'shikov, O.D.; Borisov, V.V.; Sorokin, S.I.; Krutovertsev, S.A.; Kharkevich, S.I.; Ivanova, O.M.

1994-01-01

The influence of humid air ammonia mixture on crystal pentahydrate of cobalt(2) perrhenate has been studied by the methods of PES, IR spectroscopy thermal analysis and electrophysical measurements. It is shown that with an increase in ammonia content in gaseous phase cobalt perrhenate successively transforms into diaquodiammine-, tetrammine- and μ-dioxo-bis-(tetrammine) derivatives of cobalt. Reversibility of dioxocomplex formation and a correlation between the change in electrophysical properties of crystal sample and change in ammonia content in gaseous phase are pointed out. 16 refs.; 4 figs.; 1 tab

Nitrogen induced ferromagnetism in Cobalt doped BaTiO3

Directory of Open Access Journals (Sweden)

Chandrima Mitra

2012-09-01

Full Text Available The electronic structure and magnetism of Cobalt doped BaTiO3 (BaTi1−xCoxO3 is investigated. Substitutional Nitrogen on an Oxygen site is found to play an important role in inducing net magnetic moments in the system. The presence of a Nitrogen atom as nearest neighbour to a Cobalt atom is crucial in producing spin splitting of both the Nitrogen and Cobalt states thereby introducing a net local magnetic moment. The introduction of Nitrogen is further found to enhance ferromagnetic interactions between Cobalt atoms.

Effect of Organic Pollutants on Migration of Radionuclides in Soil

International Nuclear Information System (INIS)

Nasr, R.G.A.

2012-01-01

The aim of this thesis is to study the effect of organic pollutants on the mobility of selected heavy metal (pb 2+ ) and radionuclide ( 60 Co) in an Egyptian agricultural soil and in a clay fraction separated from the soil. The effect of presence of natural organic compounds such as humic acid is also studied

Nano cobalt oxides for photocatalytic hydrogen production

KAUST Repository

Mangrulkar, Priti A.

2012-07-01

Nano structured metal oxides including TiO 2, Co 3O 4 and Fe 3O 4 have been synthesized and evaluated for their photocatalytic activity for hydrogen generation. The photocatalytic activity of nano cobalt oxide was then compared with two other nano structured metal oxides namely TiO 2 and Fe 3O 4. The synthesized nano cobalt oxide was characterized thoroughly with respect to EDX and TEM. The yield of hydrogen was observed to be 900, 2000 and 8275 mmol h -1 g -1 of photocatalyst for TiO 2, Co 3O 4 and Fe 3O 4 respectively under visible light. It was observed that the hydrogen yield in case of nano cobalt oxide was more than twice to that of TiO 2 and the hydrogen yield of nano Fe 3O 4 was nearly four times as compared to nano Co 3O 4. The influence of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Synthesis and characterization of cobalt-manganese oxides

International Nuclear Information System (INIS)

Valencia, J.; Arias, N.P.; Giraldo, O.; Rosales-Rivera, A.

2012-01-01

Cobalt doped/un-doped manganese oxides materials were synthesized at various doping rates by soft chemical reactions, oxidation-reduction method, which allows generating a metal-mixed oxide. The synthesized materials were characterized using several techniques including chemical analysis, X-rays diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The chemical analysis confirmed the presence of cobalt in the samples. XRD patterns reveal mainly a spinel-like structure and SEM micrographs exhibited morphology with fine aggregate of particles. TGA profiles showed weight loss due to loss of water in a first step, followed by a loss of oxygen from the lattice associated with partial reduction of Mn 4+ to Mn 3+ . VSM was used to measure the magnetization as a function of the applied magnetic field at temperatures T=50 and 300 K. Different magnetic behaviors were observed when cobalt percentage changed in the samples. These behaviors are considered to be related to the size of the particles and composition of the materials. Higher coercive field and lesser magnetization were observed for the sample with higher cobalt content.

The presence of some artificial and natural radionuclides in a Eucalyptus forest in the south of Spain

International Nuclear Information System (INIS)

Vaca, F.; Manjon, G.; Garcia-Leon, M.

2001-01-01

Long-lived artificial radionuclides ( 137 Cs, 90 Sr) were studied in a Eucalyptus plantation located in the south-west of Spain. Radionuclide concentrations were determined in different types of samples corresponding to specific forest components (soil, trees, herbs and litter). Depth profile distributions were obtained in two selected core soils. Two layers were separately measured in three other cores. The concentration factor, defined as the ratio between the mean activity concentration in a component and the mean activity concentration in the soil, was calculated for each component. The biomass of different components was estimated in order to evaluate the total density concentration (Bq/ha) of the artificial radionuclides ( 137 Cs, 90 Sr) in the Eucalyptus plantation. The transfer of the radionuclides between the different forest components can be inferred from the results. Additionally, other naturally occurring radionuclides ( 40 K, 226 Ra, 228 Ra, 228 Ac) were determined for comparison. Transport of radionuclides from forest to a nearby pulp mill is also discussed

Total quality management of cobalt-60 sources

International Nuclear Information System (INIS)

Malkoske, G.R.

1999-01-01

Total Quality Management of Cobalt-60 sources by a supplier requires a life cycle approach to source management. This covers various aspects, including design, manufacturing, installation, field inspection, source surveillance and return of cobalt-60 sources at the end of their useful life. The Total Quality Management approach demonstrates a strong industry commitment to the beneficial use of gamma technology for industrial irradiation applications in both developed nations and in those nations who are developing their infrastructure and techniques for the beneficial use of this technology. MDS Nordion continues to demonstrate its support and commitment to the industry by developing and implementing state-of-the-art standards for the safe use of cobalt-60 sources

Solubility of cobalt in primary circuit solutions

International Nuclear Information System (INIS)

Lambert, I.; Joyer, F.

1992-01-01

The solubility of cobalt ferrite (CoFe 2 O 4 ) was measured in PWR primary circuit conditions, in the temperature range 250-350 deg C, and the results were compared with the ones obtained on magnetite and nickel ferrite. As in the former cases, it was found that, in the prevailing primary circuit conditions, the solubility of the cobalt ferrite was minimum at temperatures around 300 deg C, for cobalt as well as for iron. The equilibrium iron concentration is significantly lower than in the case of magnetite. The results are discussed in relation with the POTHY code, based only on thermodynamic laws and data, used for the prediction of the primary circuit chemistry

Determination of concentration factors for Chromium cesium, iron and cobalt in corvine and shrimp in the vicinities of Almirante Alvaro Alberto Nuclear Power Plant

International Nuclear Information System (INIS)

Kamel, L.N.

1988-01-01

In order to verify if the concentration factors for dose calculations in critical population recommended by the International Atomic Energy (IAEA), on the Safety Series 57, are in agreement with local factors, studies were carried out at Piraquara de Dentro bay, a region in the vicinities of the Almirante Alvaro Alberto Nuclear Power Plant (CNAAA). Chromium, caesium, iron and cobalt concentration factors for corvine and shrimp were determined using the activation analysis method by neutrons, taking into account the same behaviour between radioactive and stable from the same physicochemical form. This study has evidenced that: The local values of cesium, iron and cobalt concentration factors for corvine (fish) are in the same order of magnitude of the IAEA recommended values; The chromium, caesium and cobalt concentration factor values determined for shrimp for Piraquara de Dentro bay are in the same order of magnitude or smaller than those proposed by IAEA, while the concentration factor value for ion is one order of magnitude higher than the IAEA recommended value. (author) [pt

Comparative study of fixation of Co57 labelled bleomycin, labelled gallium citrate and Hg197 labelled mercury chloride, benign or malignant pulmonary lesions

International Nuclear Information System (INIS)

Bertrand, A.; Vaillant, G.; Robert, J.; Vaillant, D.; Nouel, J.P.; Delorme, J.; Lamy, P.

1975-01-01

Over the last ten years, numerous labelled molecules have been used in lung diseases, in order to attempt definite localisation of primary or secondary carcinoma. Three of these substances are now used: cobalt 57-labelled bleomycin, Hg 197 Cl 2 and Ga 67 citrate. A study of 34 patient with malignant or tuberculous lung disease with definite diagnosis, permitted demonstration of the fact that the highest uptake, or the best images, were obtained with labelled bleomycin. However, the long period of Co 57 limits its indications in young subjects and, in these cases, HgCl 2 is indicated [fr

Cobalt source calibration

International Nuclear Information System (INIS)

Rizvi, H.M.

1999-01-01

The data obtained from these tests determine the dose rate of the two cobalt sources in SRTC. Building 774-A houses one of these sources while the other resides in room C-067 of Building 773-A. The data from this experiment shows the following: (1) The dose rate of the No.2 cobalt source in Building 774-A measured 1.073 x 10 5 rad/h (June 17, 1999). The dose rate of the Shepherd Model 109 Gamma cobalt source in Building 773-A measured 9.27 x 10 5 rad/h (June 25, 1999). These rates come from placing the graduated cylinder containing the dosimeter solution in the center of the irradiation chamber. (2) Two calibration tests in the 774-A source placed the graduated cylinder with the dosimeter solution approximately 1.5 inches off center in the axial direction. This movement of the sample reduced the measured dose rate 0.92% from 1.083 x 10 5 rad/h to 1.073 x 10 5 rad/h. and (3) A similar test in the cobalt source in 773-A placed the graduated cylinder approximately 2.0 inches off center in the axial direction. This change in position reduced the measured dose rate by 10.34% from 1.036 x 10 6 to 9.27 x 10 5 . This testing used chemical dosimetry to measure the dose rate of a radioactive source. In this method, one determines the dose by the chemical change that takes place in the dosimeter. For this calibration experiment, the author used a Fricke (ferrous ammonium sulfate) dosimeter. This solution works well for dose rates to 10 7 rad/h. During irradiation of the Fricke dosimeter solution the Fe 2+ ions ionize to Fe 3+ . When this occurs, the solution acquires a slightly darker tint (not visible to the human eye). To determine the magnitude of the change in Fe ions, one places the solution in an UV-VIS Spectrophotometer. The UV-VIS Spectrophotometer measures the absorbency of the solution. Dividing the absorbency by the total time (in minutes) of exposure yields the dose rate

Transfer pathways of {sup 54}Mn, {sup 57}Co, {sup 85}Sr, {sup 103}Ru and {sup 134}Cs in rice and radish plants directly contaminated at different growth stages

Energy Technology Data Exchange (ETDEWEB)

Choi, Y.H. E-mail: yhchoi1@kaeri.re.kr; Lim, K.M.; Yu, D.; Park, H.G.; Choi, Y.G.; Lee, C.M

2002-03-01

In order to study radionuclide transfer pathways related to direct contamination of plants, the above-ground parts of rice and radish plants were sprayed with a solution containing {sup 54}Mn, {sup 57}Co, {sup 85}Sr, {sup 103}Ru and {sup 134}Cs in a greenhouse at 5 or 6 different times. Showing little difference among radionuclides, the interception factor increased as plants grew to maturity. Its highest observed value was 0.94 in rice and 0.83 in radish. Weathering losses of the intercepted activity by harvest were 32-89% in rice and 32-85% in radish depending on application time and radionuclide. Half lives for weathering loss were estimated to be longer on the whole for earlier applications. The translocation factor varied with application time by factors of 6-110 for hulled rice seeds and 2-23 for radish roots depending on the radionuclide. It varied with radionuclides by factors of 6-800 depending on application time and plant species. It was highest in the plants sprayed during active seed growth for rice and during early plant growth for radish. In general, {sup 134}Cs and {sup 57}Co had the highest translocation factors followed by {sup 54}Mn, {sup 85}Sr and {sup 103}Ru. Based on the experimental results, radionuclide concentrations in the edible parts of mature plants were predicted for unit deposition.

Piezoelectric properties and thermal stabilities of cobalt-modified potassium bismuth titanate

International Nuclear Information System (INIS)

Guo, Zhen-Lei; Wang, Chun-Ming; Zhao, Tian-Long; Yu, Si-Long; Cao, Zhao-Peng

2013-01-01

The cobalt-modified potassium bismuth titanate (K 0.5 Bi 4.5 Ti 4 O 15 , KBT) piezoelectric ceramics have been prepared using conventional solid–state reaction. X-ray diffraction analysis revealed that the cobalt-modified KBT ceramics have a pure four-layer (m = 4) Aurivillius-type structure. The dielectric, ferroelectric, and piezoelectric properties of cobalt-modified KBT ceramics were investigated in detail. The piezoelectric activities of KBT ceramics were significantly improved by the cobalt modification. The reasons for piezoelectric activities enhancement with cobalt modification were given. The piezoelectric coefficient d 33 and Curie temperature T c for the 5 mol% cobalt-modified KBT ceramics (KBT-Co5) were found to be 28 pC/N and 575 °C, respectively. The DC resistivity, frequency constants (N p and N t ), and electromechanical properties at elevated temperature were investigated, indicating the cobalt-modified KBT piezoelectric ceramics possess stable piezoelectric properties up to 500 °C. The results show the cobalt-modified KBT ceramics are potential materials for high temperature piezoelectric applications. - Highlights: • We examine the piezoelectric properties of the cobalt-modified K 0.5 Bi 4.5 Ti 4 O 15 . • A high level of piezoelectric activities (d 33 = 28 pC/N) are obtained. • High Curie temperature (T c = 575 °C) is acquired for the optimal composition. • The Co-modified K 0.5 Bi 4.5 Ti 4 O 15 is promising as high temperature materials

Radiochemical schemes of obtaining 89Sr and 90Y radionuclides

International Nuclear Information System (INIS)

Usarov, Z. O.

2010-03-01

Key words: strontium-89, yttrium-90, extraction and extraction-chromatographic purification of radionuclides, radiopharmaceuticals. Subjects of research: strontium-89 and yttrium-90 radionuclides and their chloride forms. Purpose of work is developing of radiochemical technologies on obtaining of 89 Sr and 90 Y on the WWR-SM reactor with high radionuclide purity. Methods of research: extraction and extraction-chromatographic methods of radionuclides separation, beta- and gamma-spectrometric methods of activity measuring. The results obtained and their novelty: Were determined the conformity to laws of Y and Sr distribution in two-phase systems TBP-HNO 3 , TBP-NH 4 NO 3 , TBP-HCI, HDEHP-NO 3 , HDEHP-NH 4 NO 3 and HDEHP-HCI. Were determined the conformity to laws of Y and Sr distribution in systems with craun ethers DB-18K-6 and DTBDB-18K-6 from water solutions of HNO 3 . Radiochemical technologies on obtaining of 89 Sr and 90 Y radionuclides including radiochemical process of yttrium target with using the systems TBP-HNO 3 and HDEHP/Teflone were developed. Practical value: the radiochemical technology of obtaining 89 Sr with high radionuclide purity was developed. The method of preparation a chloride compound of 89 SrCl 2 which is used as a drug form for preparation of 89 Sr- 'Metastron' was developed. The relatively simple method of on the way obtaining 90 Y in the reactor with high radionuclidic purity that is useful for follow using in medical practice was offered. Degree of embed and economic effectivity: the developed technologies have approbation in manufacturing conditions in Radiopreparat Enterprise of INP AS RU and were offered for receiving of domestic preparations against of import foreign analogues. The statement about using the invention by obtained patent is attached to dissertation. Field of application: the received results will be introduced in manufacture at Radiopreparat Enterprise of INP AS RU for receiving of domestic preparations

Gamma spectrometric validation of measurements test of radionuclides in food matrices

International Nuclear Information System (INIS)

Rosa, Mychelle M.L.; Custodio, Luis G.; Bonifacio, Rodrigo L.; Taddei, Maria Helena T.

2013-01-01

In a testing laboratory the quality system encompasses a set of activities planned and systematic, which ensure the traceability process of an analysis, which is based on the standards NBR ISO/TEC 17025. With the need for analysis of radionuclides in food products to meet the requirements of import and export, accreditation of testing on this standard becomes increasingly necessary. The Gamma Spectrometry is a technique used for direct determination of radionuclides in different matrices, among them the food, being possible the simultaneous determination of different radionuclides in the same sample without the need for a chemical separation. In the process of Accreditation the methodology validation is an important step that includes testing accuracy, traceability, linearity and recovery. This paper describes the procedures used to validate the assay for determining radionuclides using gamma spectrometry in food. These procedures were performed through analysis of a certificated reference material by the International Atomic Energy Agency (IAEA Soil 327), analysis of samples of milk powder prepared from the doping with certified liquid standards also by the results obtained in the participation of tests of proficiency in analysis of environmental samples. (author)

The cobalt radioactive isotopes in environment; Les isotopes radioactifs du cobalt dans l'environnement

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

For the year 1993 the total activity released in cobalt is 69 GBq for the whole of nuclear power plants. The part of activity in cobalt for La Hague in 1993 is 8 GBq of {sup 58}Co and 2 GBq of {sup 60}Co. The radioactive isotopes released by nuclear power plants or the reprocessing plant of La Hague under liquid effluents are shared by half between {sup 58}Co and {sup 60}Co. The exposure to sealed sources is the most important risk for the cobalt. The risk of acute exposure can associate a local irradiation of several decades of grays inducing a radiological burns, deep burn to treat in surgery by resection or graft even amputation. A global irradiation of organism for several grays induces an acute irradiation syndrome, often serious. At long term the stochastic effects are represented by leukemia and radio-induced cancers. The increase of probability of their occurrence is 1% by sievert. We must remind that the natural spontaneous probability is 25%. (N.C.)

Radionuclide generators

International Nuclear Information System (INIS)

Lambrecht, R.M.; Wollongong Univ.; Tomiyoshi, K.; Sekine, T.

1997-01-01

The present status and future directions of research and development on radionuclide generator technology are reported. The recent interest to develop double-neutron capture reactions for production of in vivo generators; neutron rich nuclides for radio-immunotherapeutic pharmaceuticals: and advances with ultra-short lived generators is highlighted. Emphasis is focused on: production of the parent radionuclide; the selection and the evaluation of support materials and eluents with respect to the resultant radiochemical yield of the daughter, and the breakthrough of the radionuclide parent: and, the uses of radionuclide generators in radiopharmaceutical chemistry, biomedical and industrial applications. The 62 Zn → 62 Cu, 66 Ni → 66 Cu, 103m Rh → 103 Rh, 188 W → 188 Re and the 225 Ac → 221 Fr → 213 Bi generators are predicted to be emphasized for future development. Coverage of the 99 Mo → 99m Tc generator was excluded, as it the subject of another review. The literature search ended June, 1996. (orig.)

Characterization of a Cobalt-Tungsten Interconnect

DEFF Research Database (Denmark)

Harthøj, Anders; Holt, Tobias; Caspersen, Michael

2012-01-01

is to act both as a diffusion barrier for chromium and provide better protection against high temperature oxidation than a pure cobalt coating. This work presents a characterization of a cobalt-tungsten alloy coating electrodeposited on the ferritic steel Crofer 22 H which subsequently was oxidized in air......A ferritic steel interconnect for a solid oxide fuel cell must be coated in order to prevent chromium evaporation from the steel substrate. The Technical University of Denmark and Topsoe Fuel Cell have developed an interconnect coating based on a cobalt-tungsten alloy. The purpose of the coating...... for 300 h at 800 °C. The coating was characterized with Glow Discharge Optical Spectroscopy (GDOES), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The oxidation properties were evaluated by measuring weight change of coated samples of Crofer 22 H and Crofer 22 APU as a function...

Association between cobalt allergy and dermatitis caused by leather articles

DEFF Research Database (Denmark)

Bregnbak, David; Thyssen, Jacob P; Zachariae, Claus

2015-01-01

BACKGROUND: Cobalt is a strong skin sensitizer and a prevalent contact allergen. Recent studies have recognized exposure to leather articles as a potential cause of cobalt allergy. OBJECTIVES: To examine the association between contact allergy to cobalt and a history of dermatitis resulting from...... exposure to leather. METHODS: A questionnaire case-control study was performed: the case group consisted of 183 dermatitis patients with a positive patch test reaction to cobalt chloride and a negative patch test reaction to potassium dichromate; the control group consisted of 621 dermatitis patients who...... did not react to either cobalt or chromium in patch testing. Comparisons were made by use of a χ(2) -test, Fisher's exact, and the Mann-Whitney test. Logistic regression analyses were used to test for associations while taking confounding factors into consideration. RESULTS: Leather was observed...

Metal Separations and Recovery in the Mining Industry

Science.gov (United States)

Izatt, Steven R.; Bruening, Ronald L.; Izatt, Neil E.

2012-11-01

Molecular Recognition Technology (MRT) plays an important role in the hydrometallurgical processing dissolved entities in solutions in the mining industry. The status of this industry with respect to sustainability and environmental issues is presented and discussed. The roles of MRT and ion exchange in metal separation and recovery processes in the mining industry are discussed and evaluated. Examples of MRT separation processes of interest to the mining community are given involving gold, cobalt purification by extraction of trace cadmium, rhenium, and platinum group metals (PGMs). MRT processes are shown to be sustainable, economically viable, energy efficient, and environmentally friendly, and to have a low carbon footprint.

Multiwalled Carbon Nanotubes Decorated with Cobalt Oxide Nanoparticles

Directory of Open Access Journals (Sweden)

D. G. Larrude

2012-01-01

Full Text Available Multiwalled carbon nanotubes (MWCNTs synthesized by spray pyrolysis were decorated with cobalt oxide nanoparticles using a simple synthesis route. This wet chemistry method yielded nanoparticles randomly anchored to the surface of the nanotubes by decomposition of cobalt nitrate hexahydrate diluted in acetone. Electron microscopy analysis indicated that dispersed particles were formed on the MWCNTs walls. The average size increased with the increasing concentration of cobalt nitrate in acetone in the precursor mixture. TEM images indicated that nanoparticles were strongly attached to the tube walls. The Raman spectroscopy results suggested that the MWCNT structure was slightly damaged after the nanoparticle growth.

Radionuclide contaminant analysis of small mammels, plants and sediments within Mortandad Canyon, 1994

International Nuclear Information System (INIS)

Bennett, K.; Biggs, J.; Fresquez, P.

1996-01-01

Small mammals, plants and sediments were sampled at one upstream location (Site 1) and two downstream locations (Site 2 and Site 3) from the National Pollution Discharge Elimination System outfall number-sign 051-051 in Mortandad Canyon, Los Alamos County, New Mexico. The purpose of the sampling was to identify radionuclides potentially present, to quantitatively estimate and compare the amount of radionuclide uptake at specific locations (Site 2 and Site 3) within Mortandad Canyon to an upstream site (Site 1), and to identify the primary mode (inhalation ingestion, or surface contact) of contamination to small mammals. Three composite samples of at least five animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. In addition, three composite samples were also collected for plants and sediments at each site. Samples were analyzed for 241 Am, 90 Sr, 238 Pu, 239 Pu, and total U. With the exception of total U, all mean radionuclide concentrations in small mammal carcasses and sediments were significantly higher at Site 2 than Site 1 or Site 3. No differences were detected in the mean radionuclide concentration of plant samples between sites. However, some radionuclide concentrations found at all three sites were higher than regional background. No differences were found between mean carcass radionuclide concentrations and mean pelt radionuclide concentrations, indicating that the two primary modes of contamination may be equally occurring

Radionuclides difficult to measure in waste packages. Final report

Energy Technology Data Exchange (ETDEWEB)

Thierfeldt, S; Deckert, A [Brenk Systemplanung, Aachen (Germany)

1995-11-01

In this study nuclide specific correlation analyses between key nuclides that can be easily measured and nuclides that are difficult to measure are presented. Data are taken from studies and data compilations from various countries. The results of this study can serve to perform assays of the nuclide specific radionuclide contents in waste packages by gamma measurements of {sup 60}Co and {sup 137}Cs and calculation of the contents of other nuclides via the correlation analyses, sometimes referred to as `scaling factor method`. It can thus be avoided to have to take samples from the waste for separate analysis. An attempt is made to also investigate the physical and chemical backgrounds behind the proposed correlations. For example, a formation pathway common to the two nuclides to be correlated can be regarded as an explanation, if a good correlation is found. On the other hand, if the observed correlation is of poor quality, reasons may possibly lie in different behaviour of the two nuclides in the water system of the nuclear plant. This implies not only chemical solubility, transfer constants etc. in the water system, which would not only affect the proportionality between the two nuclides, but a different behavior in different parts of the water system must be assumed (e.g. different filter efficiencies etc). 47 refs, 57 figs, 40 tabs.

Transport properties of cobalt at low temperatures

DEFF Research Database (Denmark)

Radharkishna, P.; Nielsen, Mourits

1965-01-01

Measurements are made of electrical resistivity, absolute thermoelectric power, and thermal conductivity of polycrystalline cobalt between 1.2 and 6 K; results are discussed on basis of inter-electronic scattering.......Measurements are made of electrical resistivity, absolute thermoelectric power, and thermal conductivity of polycrystalline cobalt between 1.2 and 6 K; results are discussed on basis of inter-electronic scattering....

Artificial radionuclides in the atmosphere over Lithuania

International Nuclear Information System (INIS)

Lujaniene, G.; Sapolaite, J.; Remeikis, V.; Lujanas, V.; Aninkevicius, V.

2006-01-01

Systematic observations of radionuclide composition and concentration in the atmosphere have been carried out at the Institute of Physics in Vilnius since 1963. An increase in activity concentration of radionuclides in the atmosphere was observed after nuclear weapon tests and the Chernobyl NPP accident. At present the radiation situation in Lithuania is determined by two main sources of radionuclides, forest fire and resuspension products transferred from highly polluted region of the Ukraine and Belarus. During forest fires the increase in activity concentration of 1 37Cs in the atmosphere was registered in many countries and in Lithuania as well. This work summarizes the experimental data on transport of cesium, plutonium, americium from the highly contaminated territories after the Chernobyl accident. The activity concentrations of 1 37Cs were measured in two - three days samples while plutonium and americium in monthly samples. In addition, the analyses of the events of the increase activity concentration, meteorological situation, speciation of radionuclides and mechanisms of formation and transformation of aerosol carriers of radionuclides are presented. Aerosols were sampled on perchlorvinyl filters and the large volume air samplers with a flow rate from 2400 m 3 /h to about 6000 m 3 /h were used. The radiochemical analyses of monthly samples of aerosol ashes (about 30 g) were performed. For separation of Pu isotopes the TOPO/cyclohexane extraction and radiochemical purification using UTEVA resin were performed, Am was separated after TOPO/cyclohexane extraction using TRU and TEVA resins (100-150 μm). 2 42Pu and 2 43Am were used as tracers in the separation procedure. The alpha spectrometry measurements of Pu and Am isotopes deposited on a stainless steel disc were carried out with the Alphaquattro (Silena) spectrometer. 1 37Cs was determined by gamma-ray spectrometry using the high purity HPGe detector (resolution - 1.9 keV/1.33 Mev, efficiency - 42

Perfluorinated cobalt phthalocyanine effectively catalyzes water electrooxidation

KAUST Repository

Morlanes, Natalia Sanchez

2014-12-08

Efficient electrocatalysis of water oxidation under mild conditions at neutral pH was achieved by a fluorinated cobalt phthalocyanine immobilized on fluorine-doped tin oxide (FTO) surfaces with an onset potential at 1.7 V vs. RHE. Spectroscopic, electrochemical, and inhibition studies indicate that phthalocyanine molecular species are the operational active sites. Neither free cobalt ions nor heterogeneous cobalt oxide particles or films were observed. During long-term controlled-potential electrolysis at 2 V vs. RHE (phosphate buffer, pH 7), electrocatalytic water oxidation was sustained for at least 8 h (TON ≈ 1.0 × 105), producing about 4 μmol O2 h-1 cm-2 with a turnover frequency (TOF) of about 3.6 s-1 and no measurable catalyst degradation.

A spot test for detection of cobalt release – early experience and findings

DEFF Research Database (Denmark)

Thyssen, Jacob P.; Menné, Torkil; Johansen, Jeanne D.

2010-01-01

Background: It is often difficult to establish clinical relevance of metal exposure in cobalt-allergic patients. Dermatologists and patients may incorrectly assume that many metallic items release cobalt at levels that may cause cobalt dermatitis. Cobalt-allergic patients may be unaware that they...

Innovative methods to stabilize liquid membranes for removal of radionuclides from groundwater

Energy Technology Data Exchange (ETDEWEB)

Lokhandwala, K. [Membrane Technology and Research, Inc., Menlo Park, CA (United States)

1997-10-01

In this Phase I Small Business Innovation Research program, Membrane Technology Research, Inc., is developing a stable liquid membrane for extracting uranium and other radionuclides from groundwater. The improved membrane can also be applied to separation of other metal ions from aqueous streams in industrial operations.

Radionuclide separation and processing for recycle or disposal

International Nuclear Information System (INIS)

Allen, W.O.; Morrey, J.R.; Fryberger, T.B.; Wolf, S.M.; Lien, S.C.T.

1992-01-01

The U.S. Department of Energy (DOE) Office of Technology Development (OTD) is sponsoring research and development on advanced radiochemical separations, at a modest level, with the long-term goals of reducing the volume of deep geologic repository-disposed waste and the toxicity of low-level waste disposed as cement grout in a near-surface vault. This will help reduce overall environmental risks and the cost of waste management. (author)

Assessment of cobalt levels in wastewater, soil and vegetable ...

African Journals Online (AJOL)

User

Key words: Cobalt level, Kubanni River, soil, vegetable, wastewater. INTRODUCTION. Cobalt is ... metals released into the environment from a variety of anthropogenic activities ..... Heavy Metal Stress in Plants, 2nd Edition,. Springer,. United.

Synthesis and phosphatase activity of a Cobalt(II) phenanthroline ...

Indian Academy of Sciences (India)

MAMONI GARAI

2017-09-19

Sep 19, 2017 ... Synthesis and phosphatase activity of a Cobalt(II) phenanthroline complex. MAMONI GARAIa ... tion, cobalt complexes have gained importance because of their application as ... 2.3 Physical measurements. Infrared spectrum ...

Radionuclides in terrestrial ecosystems

International Nuclear Information System (INIS)

Allen, S.E.; Horrill, A.D.; Howard, B.J.; Lowe, V.P.W.; Parkinson, J.A.

1983-07-01

The subject is discussed under the headings: concentration and spatial distribution of radionuclides in grazed and ungrazed saltmarshes; incorporation of radionuclides by sheep grazing on an estuarine saltmarsh; inland transfer of radionuclides by birds feeding in the estuaries and saltmarshes at Ravenglass; radionuclides in contrasting types of coastal pastures and taken up by individual plant species found in west Cumbria; procedures developed and used for the measurement of alpha and gamma emitters in environmental materials. (U.K.)

Correlation between morphology and magnetic properties of electrochemically produced cobalt powder particles

Directory of Open Access Journals (Sweden)

Maksimović Vesna M.

2015-01-01

Full Text Available Cobalt 3D powder particles were successfully prepared by the galvanostatic electrodeposition. Electrodeposited cobalt powder were characterized by X-ray diffraction (XRD, scanning electron microscope (SEM, Energy Dispersive Spectroscopy (EDS analysis and SQUID magnetometry. It has been shown that morphology, structure and magnetic properties of cobalt particles are closely associated and can be easily controlled by adjusting process parameters of electrodeposition. Morphology of cobalt powder particles is strongly affected by hydrogen evolution reaction as a parallel reaction to cobalt electrodeposition. Depending on the applied current density, the two types of powder particles were formed: dendrites at lower and spongy-like particles at higher current densities. Morphologies and structures of powder particles are correlated with their magnetic properties, and compared with those of the bulk cobalt. In comparison with the properties of bulk cobalt, the obtained 3D structures exhibited a decreased saturation magnetization (MS, but an enhanced coercivity (HC which is explained by their peculiar morphology. [Projekat Ministarstva nauke Republike Srbije, br. III 45012

Reference sources for radionuclide calibrations in nuclear programmes

International Nuclear Information System (INIS)

Almeida, M.C.M. de; Delgado, J.U.; Poledna, R.; Silva, R.L. da; Oliveira, E.M. de; Di Prinzio, M.A.R.

2009-01-01

The radionuclide metrology laboratories aim to provide radioactive standards for detector calibrations in nuclear safety areas. To produce the reference sources to be furnished to users the following standards of 57 Co, 60 Co, 133 Ba, 241 Am, 152 Eu and 166 Ho are commonly used. In this work was made a verifying of the uncertainties obtained for the two methods: comparative (sample-standards) and efficiency curve. The total uncertainties obtained by sample-standard method varied from 0.4 to 1.2% (k = 1). The results using efficiency curve method to the same radioisotopes and same conditions are between 0.9 to 2.2% (k = 1). (author)

Radionuclide data

International Nuclear Information System (INIS)

Anon.

1992-01-01

Chapter 8 presents tables on selected alpha, beta, gamma and x-ray emitters by increasing energy; information on specific activity for selected radionuclides; naturally occurring radionuclides; the natural decay series; and the artificially produced neptunium series. A table of alpha emitters is listed by increasing atomic number and by energy. The table of β emitters presented is useful in identifying β emitters whose energies and possibly half-lives have been determined by standard laboratory techniques. It is also a handy guide to β-emitting isotopes for applications requiring specific half-lives and/or energies. Gamma rays for radionuclides of importance to radiological assessments and radiation protection are listed by increasing energy. The energies and branching ratios are important for radionuclide determinations with gamma spectrometry detectors. This section also presents a table of x-ray energies which are useful for radiochemical analyses. A number of nuclides emit x-rays as part of their decay scheme. These x-rays may be counted with Ar proportional counters, Ge planar or n-type Ge co-axial detectors, or thin crystal NaI(T1) scintillation counters. In both cases, spectral measurements can be made and both qualitative and quantitative information obtained on the sample. Nuclear decay data (energy and probability by radiation type) for more than one hundred radionuclides that are important to health physicists are presented in a schematic manner

Synthesis and characterization of cobalt-manganese oxides

Energy Technology Data Exchange (ETDEWEB)

Valencia, J. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis 55455-0153 (United States); Arias, N.P. [Laboratorio de Materiales Nanoestructurados y Funcionales, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Departamento de Ingenieria Electrica, Electronica y Computacion, Facultad de Ingenieria y Arquitectura, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Giraldo, O. [Laboratorio de Materiales Nanoestructurados y Funcionales, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Rosales-Rivera, A., E-mail: arosalesr@unal.edu.co [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia)

2012-08-15

Cobalt doped/un-doped manganese oxides materials were synthesized at various doping rates by soft chemical reactions, oxidation-reduction method, which allows generating a metal-mixed oxide. The synthesized materials were characterized using several techniques including chemical analysis, X-rays diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The chemical analysis confirmed the presence of cobalt in the samples. XRD patterns reveal mainly a spinel-like structure and SEM micrographs exhibited morphology with fine aggregate of particles. TGA profiles showed weight loss due to loss of water in a first step, followed by a loss of oxygen from the lattice associated with partial reduction of Mn{sup 4+} to Mn{sup 3+}. VSM was used to measure the magnetization as a function of the applied magnetic field at temperatures T=50 and 300 K. Different magnetic behaviors were observed when cobalt percentage changed in the samples. These behaviors are considered to be related to the size of the particles and composition of the materials. Higher coercive field and lesser magnetization were observed for the sample with higher cobalt content.

Estimation of cobalt release from feed water heater tubes of BWRs

International Nuclear Information System (INIS)

Uchida, S.; Kitamura, M.; Ozawa, Y.

1983-01-01

To evaluate the release source of cobalt from heater tubes of the feed water line, release rate measurements were carried out by detecting 60 Co released from irradiated stainless steel in contact with neutral water at an oxygen concentration of 20 ppb. The dependences of cobalt release rate on temperature, flow velocity and exposure time were studied after 670 hours of release experiments, and an empirical equation (which is presented) was obtained in the temperature range from 150 to 240 deg C. A decrease in the cobalt release rate above 250 deg C was considered due to the formation of a protective oxide layer. From these data, the amount of cobalt released from individual feed water heaters was evaluated. It was demonstrated that low cobalt containing stainless steel was economically applied only in the higher temperature region of the heater (20% of the total surface) to reduce cobalt feed rate into the reactor (to approx. 1/2). (author)

Detection of gastroesophageal reflux in survivors of congenital diaphragmatic hernia: A radionuclide scintigraphic study in 26 children

International Nuclear Information System (INIS)

Thomas, E.J.; Bharathi Dasan, J.; Chandrasekhar, N.; Tripathi, M.; Kumar, R.; Kumar, A.; Malhotra, A.; Gupta, D.K.; Mitra, D.K.

2002-01-01

Introduction: Anatomical and functional esophageal abnormalities in survivors with CDH are well known. Gastro-esophageal Reflux (GER) is a common cause of long-term morbidity in survivors of congenital diaphragmatic hernia. The incidence of GER in these patients varies from 20-70% using various modalities. Aims: The present retrospective analysis was undertaken to find out the incidence of GER detected by radionuclide scintigraphy in survivors of congenital diaphragmatic hernia. Materials and Methods: Radionuclide scintigraphy for GER detection were performed in 26 survivors of congenital diaphragmatic hernia (17 male and 9 female) with a mean age of 19 months; age range 10 days to 56 months. Seven of the children had symptoms suggestive of GER. Of these 7, 3 had recurrent respiratory tract infection, 2 had regurgitation, 1 had vomiting and 1 had epigastric pain. The remaining 19 children were referred as part of routine follow up. All the children underwent radionuclide scintigraphy with 100-200 micro curie (3.7 -7.4MBq) of Tc99m-Sulphur Colloid. Results: The radionuclide scintigraphy detected GER in 11 out of 26(42.3%) children. Among the 7 symptomatic children, 4 (57%) had positive scintigraphic studies for reflux. Of these 4, 3(75%) had proximal reflux and 1 had distal reflux. Of the 19 asymptomatic patients, 7 (37%) were positive for GER on scintigraphy. Of these 7, 4 (57%) had proximal reflux and 3 (43%) had distal reflux. Conclusions: There is high incidence of GER in survivors of congenital diaphragmatic hernia irrespective of the presence or absence of symptoms suggestive of GER. Scintiscanning being a simple, noninvasive test can be used for initial evaluation of survivors of CDH for GER

A novel method to synthesize cobalt oxide (Co3O4) nanowires from cobalt (Co) nanobowls

DEFF Research Database (Denmark)

Srivastava, Akhilesh Kumar; Madhavi, S.; Ramanujan, R.V.

2010-01-01

A novel method suitable for the synthesis of the cobalt oxide (Co3O4) nanowires at targeted regions is presented in this report. Cobalt (Co) nanobowls synthesized by colloidal crystal directed assembly were transformed into Co3O4 nanowires by a simple heat treatment process. Co nanobowls exhibited...... a two phase (h.c.p. + f.c.c.) microstructure while single phase microstructure was observed for Co3O4 nanowires. Ferromagnetic Co nanobowls showed a dependence of coercivity on bowl size while Co3O4 exhibited weak ferromagnetic behavior....

A review of cobalt adsorption on transition metal oxides

International Nuclear Information System (INIS)

Walker, S.M.

1987-04-01

This report reviews studies of cobalt adsorption on transition metal oxides, in the context of corrosion product and radioactivity transport in PWR primary circuits. In general, uptake of cobalt increases with pH, with temperature and with decreasing ionic strength. Very little data are available under PWR primary circuit conditions, but the limited data available suggest that cobalt uptake by the zirconium oxide corrosion product layer on fuel pins may be significant compared to that deposited on fuel crud. If fuel crud levels can be reduced in future by coolant chemistry control then uptake by the zirconia will assume a greater relative role. It is planned to use an autoclave to study uptake of cobalt on oxidised Zircaloy surfaces at temperatures up to 593K under PWR primary circuit chemistry conditions. (author)

Carbohydrate and alditol analysis by high-performance anion-exchange chromatography coupled with electrochemical detection at a cobalt-modified electrode.

Science.gov (United States)

Casella, Innocenzo G; Contursi, Michela

2003-07-01

A cobalt oxyhydroxide film dispersed on a carbon electrode surface was characterized and proposed as an amperometric sensor for determination of alditols and carbohydrates in flowing streams. Complex mixtures of carbohydrates were separated by anion-exchange chromatography using a moderately alkaline solution as mobile phase. The cobalt modified electrode (GC-Co) was employed under a constant applied potential of 0.5 V (vs Ag/AgCl). Under these experimental conditions the detection limits (S/N=3) for all analyzed electroactive molecules ranged between 0.3 micromol L(-1) and 1.5 micromol L(-1) and the dynamic linear ranges spanned generally three orders of magnitude above the relevant detection limits. Analytical determinations of carbohydrates and alditols in red and white wines, are reported.

The Application of Moessbauer Emission Spectroscopy to Industrial Cobalt Based Fischer-Tropsch Catalysts

International Nuclear Information System (INIS)

Loosdrecht, J. van de; Berge, P. J. van; Craje, M. W. J.; Kraan, A. M. van der

2002-01-01

The application of Moessbauer emission spectroscopy to study cobalt based Fischer-Tropsch catalysts for the gas-to-liquids process was investigated. It was shown that Moessbauer emission spectroscopy could be used to study the oxidation of cobalt as a deactivation mechanism of high loading cobalt based Fischer-Tropsch catalysts. Oxidation was observed under conditions that are in contradiction with the bulk cobalt phase thermodynamics. This can be explained by oxidation of small cobalt crystallites or by surface oxidation. The formation of re-reducible Co 3+ species was observed as well as the formation of irreducible Co 3+ and Co 2+ species that interact strongly with the alumina support. The formation of the different cobalt species depends on the oxidation conditions. Iron was used as a probe nuclide to investigate the cobalt catalyst preparation procedure. A high-pressure Moessbauer emission spectroscopy cell was designed and constructed, which creates the opportunity to study cobalt based Fischer-Tropsch catalysts under realistic synthesis conditions.

Methods of Increasing the Performance of Radionuclide Generators Used in Nuclear Medicine: Daughter Nuclide Build-Up Optimisation, Elution-Purification-Concentration Integration, and Effective Control of Radionuclidic Purity

Directory of Open Access Journals (Sweden)

Van So Le

2014-06-01

Full Text Available Methods of increasing the performance of radionuclide generators used in nuclear medicine radiotherapy and SPECT/PET imaging were developed and detailed for 99Mo/99mTc and 68Ge/68Ga radionuclide generators as the cases. Optimisation methods of the daughter nuclide build-up versus stand-by time and/or specific activity using mean progress functions were developed for increasing the performance of radionuclide generators. As a result of this optimisation, the separation of the daughter nuclide from its parent one should be performed at a defined optimal time to avoid the deterioration in specific activity of the daughter nuclide and wasting stand-by time of the generator, while the daughter nuclide yield is maintained to a reasonably high extent. A new characteristic parameter of the formation-decay kinetics of parent/daughter nuclide system was found and effectively used in the practice of the generator production and utilisation. A method of “early elution schedule” was also developed for increasing the daughter nuclide production yield and specific radioactivity, thus saving the cost of the generator and improving the quality of the daughter radionuclide solution. These newly developed optimisation methods in combination with an integrated elution-purification-concentration system of radionuclide generators recently developed is the most suitable way to operate the generator effectively on the basis of economic use and improvement of purposely suitable quality and specific activity of the produced daughter radionuclides. All these features benefit the economic use of the generator, the improved quality of labelling/scan, and the lowered cost of nuclear medicine procedure. Besides, a new method of quality control protocol set-up for post-delivery test of radionuclidic purity has been developed based on the relationship between gamma ray spectrometric detection limit, required limit of impure radionuclide activity and its measurement

Plasma sprayed samarium--cobalt permanent magnets

International Nuclear Information System (INIS)

Willson, M.C.; Janowiecki, R.J.

1975-01-01

Samarium--cobalt permanent magnets were fabricated by arc plasma spraying. This process involves the injection of relatively coarse powder particles into a high-temperature gas for melting and spraying onto a substrate. The technique is being investigated as an economical method for fabricating cobalt--rare earth magnets for advanced traveling wave tubes and cross-field amplifiers. Plasma spraying permits deposition of material at high rates over large areas with optional direct bonding to the substrate, and offers the ability to fabricate magnets in a variety of shapes and sizes. Isotropic magnets were produced with high coercivity and good reproducibility in magnetic properties. Post-spray thermal treatments were used to enhance the magnetic properties of sprayed deposits. Samarium--cobalt magnets, sprayed from samarium-rich powder and subjected to post-spray heat treatment, displayed energy products in excess of 9 million gauss-oersteds and coercive forces of approximately 6000 oersteds. Bar magnet arrays were constructed by depositing magnets on ceramic substrates. (auth)

The cobalt radioactive isotopes in environment

International Nuclear Information System (INIS)

2007-01-01

For the year 1993 the total activity released in cobalt is 69 GBq for the whole of nuclear power plants. The part of activity in cobalt for La Hague in 1993 is 8 GBq of 58 Co and 2 GBq of 60 Co. The radioactive isotopes released by nuclear power plants or the reprocessing plant of La Hague under liquid effluents are shared by half between 58 Co and 60 Co. The exposure to sealed sources is the most important risk for the cobalt. The risk of acute exposure can associate a local irradiation of several decades of grays inducing a radiological burns, deep burn to treat in surgery by resection or graft even amputation. A global irradiation of organism for several grays induces an acute irradiation syndrome, often serious. At long term the stochastic effects are represented by leukemia and radio-induced cancers. The increase of probability of their occurrence is 1% by sievert. We must remind that the natural spontaneous probability is 25%. (N.C.)

Crystal structure and spin state of mixed-crystals of iron with zinc and cobalt for the assembled complexes bridged by 1,3-bis(4-pyridyl)propanes

Energy Technology Data Exchange (ETDEWEB)

Dote, Haruka [Hiroshima University, Graduate School of Science (Japan); Nakashima, Satoru, E-mail: snaka@hiroshima-u.ac.jp [Hiroshima University, Natural Science Center for Basic Research and Development (Japan)

2012-03-15

Mixed crystals of cobalt and zinc were synthesized using 1,3-bis(4-pyridyl)propane (bpp) as bridging ligand and NCS{sup - } as anion. Red crystals and blue crystals were obtained. Powder X-ray diffraction patterns showed that the former is in 2D interpenetrated structure, while the latter has the same structure with Zn(NCS){sub 2}(bpp). Iron ion was introduced both into the red crystals and blue crystals of the mixed crystals of cobalt with zinc. {sup 57}Fe Moessbauer spectrum of the red crystals showed a main doublet of Fe{sup II} high-spin state at 78 K, while the spectrum of blue crystals did not show Fe{sup II} high-spin state at 78 K.

Crystal structure and spin state of mixed-crystals of iron with zinc and cobalt for the assembled complexes bridged by 1,3-bis(4-pyridyl)propanes

International Nuclear Information System (INIS)

Dote, Haruka; Nakashima, Satoru

2012-01-01

Mixed crystals of cobalt and zinc were synthesized using 1,3–bis(4–pyridyl)propane (bpp) as bridging ligand and NCS  −  as anion. Red crystals and blue crystals were obtained. Powder X-ray diffraction patterns showed that the former is in 2D interpenetrated structure, while the latter has the same structure with Zn(NCS) 2 (bpp). Iron ion was introduced both into the red crystals and blue crystals of the mixed crystals of cobalt with zinc. 57 Fe Mössbauer spectrum of the red crystals showed a main doublet of Fe II high-spin state at 78 K, while the spectrum of blue crystals did not show Fe II high-spin state at 78 K.

Calculation support for industrial production of cobalt-60 at Leningrad NPP

International Nuclear Information System (INIS)

Artemov, Vladimir; Elshin, Alexander; Ivanov, Alexander; Gorbunov, Evgeny; Ikonnikov, Roman; Pimenov, Alexander

2008-01-01

Cobalt-60 is industrially produced at the Leningrad NPP by irradiation of cobalt-59 in special-purpose facilities loaded into the RBMK reactor core (all 4 units). The paper describes calculation methods used to determine the current activity of cobalt in irradiation assemblies for their timely unloading. The described peculiarities of core calculation model account for continuous refueling, overloading of irradiation assemblies and individual thermohydraulics in each channel under variation of reactor power. Fuel burnup in the core is calculated with a time step of about 24 hours. The resulting values for cobalt activity and uncertainties are presented in the paper as well. Deviation of calculated cobalt activity from measured activity is within the experimental accuracy of 10% (at confidence probability of 0.95). (authors)

Sorption behavior of cobalt on manganese dioxide, smectite and their mixture

International Nuclear Information System (INIS)

Ohnuki, T.; Kozai, N.

1995-01-01

The sorption behavior of cobalt on manganese dioxide, the clay mineral smectite and mixtures of the two was studied by batch type sorption/desorption experiments at neutral pH. Sorption behavior was examined by sequential extraction, in which the sorbents were contacted first with a 1 M CH 3 COONH 4 solution and then with a hydroxylamine solution (NH 2 OH of 1 M with 25 weight % CH 3 COOH). More than 70% of the sorbed cobalt was desorbed from smectite with a 1 M CH 3 COONH 4 solution: about 15% of the cobalt remained on the smectite after treatment with the hydroxylamine solution. Less than 1% of the remaining cobalt was desorbed from manganese dioxide with a 1 M CH 3 COONH 4 solution; with the hydroxylamine solution, all was desorbed. In mixtures of MnO 2 and smectite that were formulated to sorb equal amounts of cobalt regardless of the MnO 2 /smectite ratio in the mixture, less than 5% of the sorbed cobalt was desorbed by treatment with 1 M CH 3 COONH 4 . The fraction of the cobalt desorbed by treatment with the hydroxylamine solution increased with increased MnO 2 in the mixtures. The fraction of the cobalt sorbed on MnO 2 in the mixture was estimated from the desorption experiments. The results showed that higher fractions were sorbed onto MnO 2 than were estimated by the weighted averages of distribution coefficients for MnO 2 and smectite. Therefore, in minerals of the mixture, manganese dioxide is a more important component than smectite for the sorption of cobalt. (orig.)

Preparation of Radiopharmaceuticals Labeled with Metal Radionuclides

Energy Technology Data Exchange (ETDEWEB)

Welch, M.J.

2012-02-16

oxygen retention of the tissue and the significantly greater retention amounting in hypoxic tissue. This hypothesis was confirmed in a series of animal studies. Cu-64 can be used both as an imaging radionuclide and a therapeutic radionuclide. The therapeutic efficacy of Cu-64 ATSM was proven in hamsters bearing the CW39 human colorectal tumors. The administration of Cu-64 ATSM significantly increased the survival time of tumor-bearing animals with no acute toxicity. This copper agent therefore shows promise for radiotherapy. The flow tracer Cu-64 PTSM also demonstrates therapeutic potential by inhibiting cancer cells implanted in animal models. Again, this inhibition occurred at doses which showed no sign of toxicity to the animals. Cu-ATSM was translated to humans, under other support a series of tumors were investigated; these included head and neck cancer, non-small cell lung cancer, cervical cancer and renal cancer. Another radionuclide that was investigated was titanium 45. This radionuclide was successfully produced by radiation of a scandium foil with 15 MeV protons. The titanium 45 was processed and separated from residual scandium by high exchange chomotrophy. Titanium titanocene has been utilized as a therapeutic agent; this compound was prepared and studied in vitro and in vivo. Another project was the preparation of cyclodextrin dimers as a new pre-targeting approach for tumor uptake. Beta-cyclodextradin and two other dimers were synthesized. These dimers were studied for the in vivo application. Work continued on the application of the radionuclide already discussed. Technetium 94m, a positron emitting radionuclide of the widely used 99m Tc nuclide was also prepared. This allows the quantification of the uptake of technetium radiopharmaceuticals. In collaboration with Professor David Piwnica-Worms, technetium 94m, sestamibi was studied in animal models and in a limited number of human subjects.

Radionuclide Concentrations in Terrestrial Vegetation and Soil Samples On and Around the Hanford Site, 1971 Through 2008