SwePub - search: L773:0236 5731 OR L773:1588 27...

Enumeration	Reference	Cover	Find
1.	Abdel-Khalek, Ahmed A., et al. (author) Chemical Studies on Uranium Extraction from Concentrated Phosphoric Acid by Using PC88A and DBBP Mixture. 2011 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer. - 0236-5731 .- 1588-2780. ; 290, s. 353-359 Journal article (peer-reviewed)abstract Liquid–liquid extraction of U (VI) from concentrated phosphoric acid by using (2-ethyl hexyl) phosphonic acid, mono (2-ethyl hexyl) ester (PC88A) and di-butyl butyl phosphonate (DBBP) has been investigated. The effect of different factors affecting the extraction process (PC88A concentration, DBBP concentration, shaking time, aqueous/organic phase ratio, phosphoric acid concentration and effect of diluents) have been investigated. The obtained data of temperature on the extraction showed that the enthalpy change is −17.15 kJ mol−1. Uranium was extracted from the strip liquor by using di (2-ethylhexyl) phosphoric acid and tri-octyl phosphine oxide mixture and finally converted to a high purity UO3 product using precipitation with hydrogen peroxide and heat treatment at 365 °C.
2.	Al-Jobori, S. M., et al. (author) Analysis of natural milk and milk powder samples by NAA 1990 In: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731 .- 1588-2780. ; 144:3, s. 229-239 Journal article (peer-reviewed)abstract As a part of the Iraqi Food'Analysis Programme /I.F.A.P./ the concentrationof Na, Mg, P, CI, K, Ca, Zn, Se, Br, Rband I in natural milk collected from different regions of Iraq, and in milkpowder samples have been determined byusing the NAA technique. It was found that except for the elements I, Rb and Br the concentration of the elements was approximately identical in both the natural milks and milk powders.
3.	Al-Jobori, S.M., et al. (author) Determination of major, minor and trace elements in Iraqi vegetabel samples by INAA 1992 In: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731 .- 1588-2780. ; 159:1, s. 29-36 Journal article (peer-reviewed)abstract Vegetable samples collected from different locations in Iraq have been analyzed by the method of instrumental neutron activation analysis for the determination of its content of major, minor and trace elements. Twenty types of vegetables have been analyzed and the concentrations of sixteen elements are presented.
4.	Aldahan, Ala, et al. (author) Particle-bound Be-10 from a low latitude arid region 2014 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 299:3, s. 1709-1713 Journal article (peer-reviewed)abstract The Be-10 isotope is widely used in geochronology, climate and environmental analyses and astrophysics where atmospheric deposition model estimate plays a vital role for the initial concentration. Data from arid regions have not been well constrained because of sparse measurement and here we present Be-10 concentration in samples of dust, soil, marine sediments and paleosol collected from an arid to semi-arid low latitude region. These results indicate concentrations that are about a factor of three lower than values expected from latitude zonal models, but are comparable with global atmospheric depositional model. The agreement and discrepancy between model and measured data are rather vital for establishing accurate initial Be-10 in the Earth's surface environment for reconstruction of paleoclimatic variability (precipitation rates and temperature).
5.	Alshamsi, Dalal M., et al. (author) Uranium isotopes in carbonate aquifers of arid region setting 2013 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 298:3, s. 1899-1905 Journal article (peer-reviewed)abstract Groundwater in arid and semiarid regions is vital resource for many uses and therefore information about concentrations of uranium isotopes among other chemical parameters are necessary. In the study presented here, distribution of U-238 and U-235 in groundwater of four selected locations in the southern Arabian peninsula, namely at two locations within the United Arab Emirates (UAE) and two locations in Oman are discussed. The analyses of the uranium isotopes were performed using ICP-MS and the results indicated a range of concentrations for U-235 and (238) U at 3-39 ng L-1 (average: 18 ng L-1) and 429-5,293 ng L-1 (average: 2,508 ng L-1) respectively. These uranium concentrations are below the higher permissible WHO limit for drinking water and also comparable to averages found in groundwater from similar aquifers in Florida and Tunisia. Negative correlation between rainfall and uranium concentrations suggests that in lithologically comparable aquifers, climate may influence the concentration of uranium in subtropical to arid regions.
6.	Aneheim, Emma, 1982, et al. (author) Astatine-211 labeling: a study towards automatic production of astatinated antibodies 2015 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 303:1, s. 979-983 Journal article (peer-reviewed)abstract Targeted alpha therapy is especially interesting for therapy of microscopic cancer tumors due to short path length and high linear energy transfer of the alpha particles. One of the most promising nuclides for targeted alpha therapy is At-211. To facilitate larger clinical studies using At-211, the current manual synthesis of radiolabeled antibodies would benefit from being transferred into an automated method. In this work, successful modifications of the manual synthesis have been performed in order to adapt it to automation. The automatic synthesis has also been tested using the modified synthesis method.
7.	Aneheim, Emma, 1982, et al. (author) Technetium chemistry in a novel group actinide extraction process 2013 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 296:2, s. 743-748 Journal article (peer-reviewed)abstract A newly developed method for advanced reprocessing of used nuclear fuel is the Group ActiNide EXtraction (GANEX) process. It is a liquid-liquid extraction process that aims at extracting all the actinides as a group from dissolved used nuclear fuel. This extraction can either be performed after a removal of the bulk uranium or directly on the dissolution liquor. At Chalmers University of Technology in Sweden a solvent that utilizes tributyl-phosphate (TBP) and a molecule from the bis-triazine bipyridine (BTBP) class of ligands dissolved in cyclohexanone has been developed for the use in a GANEX process. Previously the system has not been tested with the presence of technetium that is one of the major fission products. Technetium is often considered a problem within reprocessing since it has a chemical behaviour that differs from most other elements in the spent fuel. Therefore, a special emphasis was put on the investigation of technetium in the selected GANEX system. It was shown that technetium is readily extracted by the GANEX solvent and that cyclohexanone is the main extractant when no other metals were present in the system. It was also found that the presence of uranium decreased the overall technetium extraction despite a slight co-extraction with TBP, while irradiation of the GANEX solvent to large doses ([>1 MGy) increased its technetium extraction capability. It was also discovered that an increased nitrate concentration in the aqueous phase and an addition of other fission products both inhibited the technetium extraction even though fission product loading most likely changed the extraction mechanism to co-extraction by BTBP.
8.	Bartos, B., et al. (author) Ru-103/Rh-103m generator 2009 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 279:2, s. 655-657 Journal article (peer-reviewed)abstract Rh-103m is a very promising radionuclide for Auger electron therapy due to its very low photon/electron ratio. The goal of the present work was the elaboration a method for production of large quantities of Rh-103m for generator system. It was found that the combination of solvent extraction with evaporation of (RuO4)-Ru-103 followed by decomposition of H5IO6 makes it possible to produce Rh-103m of high radionuclidic and chemical purity.
9.	Bian, Wenjie, et al. (author) Diffusion behavior of Se(IV) and Re(VII) in biotite: effects of dry density and ionic strength 2023 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Nature. - 0236-5731 .- 1588-2780. ; 332:11, s. 4413-4425 Journal article (peer-reviewed)abstract Biotite is an important adsorption carrier in the constituent minerals of Beishan granite. In this work, the effects of compaction density and ionic strength on the diffusion behavior of Se(IV) and Re(VII) in biotite were studied by capillary in-diffusion method and diffusion cell through-diffusion method. When the compaction density decreases or the ionic strength increases, the apparent diffusion coefficient increases, and its values range between 10–11 and 10–9 m2/s. The relationship between De and εacc, ionic strength and εacc was fitted using Archie's law and compared with the parameters of other researchers.
10.	Bruskin, Alexander, et al. (author) Separation of two labeled components of [111In] -OctreoScan by HPLC 2001 In: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731 .- 1588-2780. ; 247:1, s. 95-99 Journal article (peer-reviewed)abstract [111In]-DTPA-D-Phe1-octreotide (OctreoScan®, Mallinkrodt) is widely used for detection of neuroendocrine tumors and has lately been proposed for radionuclide therapy. We found, using HPLC and a GF-250 column (Zorbax®, Hewlett Packard), that OctreoScan® can be separated in two radiolabeled components of about equal amount. The analytical conditions for a quantitative isolation indicate that the two-peptide components of OctreoScan®have different lipophilicity. The isolated components are stable and do not transform into each other at room temperature during 6 hours (shelf-life of OctreoScan®).
11.	Chen, P., et al. (author) Comparison of measurement and modeling results of the global Be-10 flux in topsoil 2017 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer. - 0236-5731 .- 1588-2780. ; 311:3, s. 2039-2045 Journal article (peer-reviewed)abstract Soils are among the major terrestrial reservoirs of atmospheric Be-10 isotope and provide information of landscape evolution history. Despite this importance, there is no overview of the global soil Be-10 fluxes in topsoil that is linked with atmospheric flux models. A comparison between measured (in topsoil) and atmospherically modeled Be-10 fluxes is presented here. The data show relatively good agreement in the latitudinal trends. This feature demonstrates the potential to use the modeling data in estimating soil development/erosion rates in large scale basins where extensive Be-10 measurements can be limited.
12.	Chen, Xuegao, et al. (author) Estimation of I-129 inventory in the oceans 2016 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 308:1, s. 59-65 Journal article (peer-reviewed)abstract Spatial distribution of oceanic I-129 inventory presented here is based on collection of data from published literatures coupled with model calculation using ArcGIS software tools. A total of 363 thiessen polygons were created for the oceans in order to cover the tremendous variability in distribution of I-129 data range. The results indicate that total I-129 oceanic inventory is approximately 7310 kg, which is mainly stored in the region of the North Atlantic and the Arctic Oceans. The concentrations of I-129 in the oceans are 3-4 orders of magnitude higher than the pre-anthropogenic level reflecting effects of post 1945 anthropogenic activities.
13.	Coenen, Heinz H., et al. (author) Open letter to journal editors on : international consensus radiochemistry nomenclature guidelines 2018 In: American Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 2160-8407. ; 61:4, s. 402-404 Journal article (other academic/artistic)
14.	Cui, Daqing, et al. (author) Reductive immobilization of Se-79 by iron canister under simulated repository environment 2009 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 282:2, s. 349-354 Journal article (peer-reviewed)abstract To understand the fate of Se-79 in a repository-like environment, the interactions between iron canister surface with dissolved selenite (SeO3 (2-)) and selenate (SeO4 (2-)) in anaerobic solutions have been investigated. Se(IV) immobilization on iron surface was observed to be about 100 times faster than that of Se(VI) at same conditions. An iron surface coated with a FeCO3 layer corrosion product is more reactive than a polished iron to immobilize Se(IV) and Se(VI). The reacted iron surfaces were analysed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), X-ray diffraction (XRD), Raman spectrometry and micro-X-ray Absorption Spectroscopy (XAS). The result show that Se(IV) and Se(VI) were reduced and precipitated. The dominating phase was found to be FeSe2..
15.	Dario, Mårten, et al. (author) Sorption of europium on TiO2 and cement at high pH in the presence of organic ligands 2006 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 270:3, s. 495-505 Journal article (peer-reviewed)abstract Organic substances present in radioactive waste lower the sorption of metal ions at the high pH in cement matrices and, hence, enhance their possible migration. The aim of this study was to develop a method to compare organic substances or their degradation products with respect to what extent they affect metal sorption. Batch sorption studies were performed with cement or TiO2 as solid phase and Eu(III) as a model element for trivalent lanthanides and actinides at pH 12.5 (representative of a cement waste matrix during the first approximately 100,000 years). Different kinds of ligands were studied in a broad concentration range, e.g., organic acids, cement additives, cleaning agents and degradation products from ion-exchange resin.
16.	De La Rosa, Nathaly, et al. (author) Quantification of lithium at ppm level in geological samples using nuclear reaction analysis 2018 In: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731 .- 1588-2780. ; 317, s. 253-259 Journal article (peer-reviewed)
17.	de la Rosa, Nathaly, et al. (author) Quantification of lithium at ppm level in geological samples using nuclear reaction analysis 2018 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 317:1, s. 253-259 Journal article (peer-reviewed)abstract Proton-induced reaction (p,α) is one type of nuclear reaction analysis (NRA) suitable especially for light element quantification. In the case of lithium quantification presented in this work, accelerated protons with an energy about of 850 keV were used to induce the 7Li(p,α)4He reaction in standard reference and geological samples such as tourmaline and other Li-minerals. It is shown that this technique for lithium quantification allowed for measurement of concentrations down below one ppm. The possibility to relate the lithium content with the boron content in a single analysis was also demonstrated using tourmaline samples, both in absolute concentration and in lateral distribution. In addition, Particle induced X-ray emission (PIXE) was utilized as a complementary IBA technique for simultaneous mapping of elements heavier than sodium.
18.	Ekberg, Christian, 1967, et al. (author) Extraction of At-211 from nitric acid solutions into various organic solvents for use as an alpha-source for radiation chemistry studies 2017 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 314:1, s. 235-239 Journal article (peer-reviewed)abstract The partitioning of At-211 from an irradiated bismuth target using solvent extraction into several organic solvents is presented. Although astatine speciation is difficult to measure given its invariably low chemical concentration its extraction here is consistent with the existence of a cationic species in nitric acid that is not reduced upon contact with the organic phase. This is consistent with previous work that postulated the most probable species in acidic solution as AtO+. The technique presented has a simple experimental set up and provides high specific activity astatine solutions compatible for use in alpha-radiolysis studies.
19.	Ekberg, Christian, 1967, et al. (author) Nitride fuel for Gen IV nuclear power systems 2018 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 318:3, s. 1713-1725 Research review (peer-reviewed)abstract Nuclear energy has been a part of the energy mix in many countries for decades. Today in principle all power producing reactors use the same techniqe. Either PWR or BWR fuelled with oxide fuels. This choice of fuel is not self evident and today there are suggestions to change to fuels which may be safer and more economical and also used in e.g. Gen IV nuclear power systems. One such fuel type is the nitrides. The nitrides have a better thermal conductivity than the oxides and a similar melting point and are thus have larger safety margins to melting during operation. In addition they are between 30 and 40% more dense with respect to fissile material. Drawbacks include instability with respect to water and a sometimes complicated fabrication route. The former is not really an issue with Gen IV systems but for use in the present fleet. In this paper we discuss both production and recycling potential of nitride fuels.
20.	Eriksson, Sofia, et al. (author) Reducing measurement uncertainty in Ni-63 measurements in reactor coolant water with high Co-60 activities 2013 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 296:2, s. 775-779 Journal article (peer-reviewed)abstract In methods for quantification of Ni-63, in e. g. reactor coolant water, a chemical separation is required due to Ni-63 being a pure beta emitter with limited means of quantification. Co-60, a common radionuclide in reactor coolant water, is not completely separated with the commonly used separation procedure, and it is not resolved from Ni-63 in the beta spectrum. The separation method discussed in this work consists of TRU resin (Eichrom) and Ni resin (Eichrom). After running the separation procedure, depending on the initial activity of Co-60, there may still remain enough Co-60 to interfere in the measurement of Ni-63. The Co-60 interference is corrected for via a gamma spectrometric measurement. This correction may, depending on the Ni-63/Co-60 ratio, introduce a large contribution to the measurement uncertainty. The aim of this work was to evaluate the possibility to reduce the measurement uncertainty of Ni-63 measurements by adding a second Ni separation to the method. Double Ni separations were performed on reactor coolant water having a Co-60 activity much higher than the Ni-63 activity (Ni-63/Co-60 = 0.01), in order to decrease the radioactivity of Co-60 in the sample. The measurement uncertainty of the Ni-63 measurement result was reduced by a factor of about three.
21.	Espegren, Fredrik, 1989, et al. (author) Chemical interaction between sea-salt and tellurium, between 300 and 1180 K 2018 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 317:1, s. 535-543 Journal article (peer-reviewed)abstract As an emergency action during the Fukushima accident, seawater was used to maintain cooling. To evaluate the effect of the salt on fission-products, sodium chloride, and tellurium were heated together using different ratios in different atmospheres (inert or oxidizing) using thermogravimetric analysis. The experiment under inert conditions showed no indication of interaction. However, under oxidizing conditions an interaction for all samples was observed that prevented an otherwise observed mass increase of the tellurium reference. The change in the appearance of the samples at increasing temperatures was studied by heating them in a furnace.
22.	Fermvik, Anna, 1978 (author) Comparison of the effect of alpha and gamma radiolysis on the extraction of americium by C5-BTBP in cyclohexanone. 2011 In: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731 .- 1588-2780. ; 289:3, s. 811-817 Journal article (peer-reviewed)abstract Solvent extraction is a separation technique suitable for the treatment of used nuclear fuel. Two immiscible phases are contacted and the metals of interest are extracted from one phase into the other, most often using so called extractants. One group of extractants is the bis(triazine)-bipyridine (BTBP) type molecules. These molecules have been developed within EU research programs for the separation of actinides from lanthanides. During such an extraction process, the components of the two phases will be exposed to ionizing radiation, since the used fuel contains many highly radioactive species. Radiolytic reactions can alter the chemistry of the extracting system, and affect the metal extraction by degradation of the extractant and the formation of degradation products. In this paper the effect of irradiation with alpha particles and gamma rays, respectively, has been studied for one of the BTBP type molecules, C5-BTBP.
23.	Greis, Christina, 1975-, et al. (author) Determination of plutonium in environmental samples with quadrupole ICP-MS 2008 In: Journal of Radioanalytical and Nuclear Chemistry. - Berlin : Springer. - 0236-5731 .- 1588-2780. ; 275:1, s. 55-70 Journal article (peer-reviewed)abstract A method for rapid determination of plutonium isotopes in environmental samples with ultrasonic nebulisation and quadrupole ICP-MS detection was established. Techniques for sample dissolution, pre-concentration and chemical separation were evaluated and the optimal scheme outlined. Comparisons with α-spectrometry and high resolution ICP-MS confirmed the suitability of the method when applied to different environmental matrices within the global fallout concentration range in the northern hemisphere as well as more contaminated sites. Operational detection limits were 0.5–1.5 fg/l for fresh waters and 0.03–0.1 ng/kg for lake sediments and saline marsh sediments.
24.	Greis, Christina, 1975-, et al. (author) Plutonium remobilization in a humic-rich lake 2007 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 277:1, s. 265-268 Journal article (peer-reviewed)abstract Fresh water from Lake Svartsjön, Sweden, was collected and four fractions were prepared: (1) adsorption on DEAE, (2) flocculation with Ca2+, (3) co-precipitation with Fe hydrous oxide and (4) co-precipitation with Mn hydrous oxide. The plutonium level in the lake is 65 fg/l (222 μBq/l), measured by ICP-QMS and ICP-SFMS. Pronounced accumulation in fractions (1) (34%) and (2) (66%), combined with observed levels of organic matter indicate that plutonium is predominantly associated with organic matter. Measurements of isotopic ratios indicate that 77% of the plutonium originates from weapons testing and the remaining appears to originate from the Chernobyl accident.
25.	Halleröd, Jenny, 1987, et al. (author) Phenyl trifluoromethyl sulfone as diluent in a grouped actinide extraction process: extraction properties of the solvent components TBP and CyMe4-BTBP 2016 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 307:3, s. 1711-1715 Journal article (peer-reviewed)abstract The grouped actinide extraction (GANEX) process combines two extractants CyMe4-BTBP and TBP in a diluent, in this study phenyl trifluoromethyl sulfone (FS-13). The extraction of U-235, Np-239, Pu-238, Am-241, Cm-244 and Eu-152 has been investigated in four different systems. System 1: 70 %vol FS-13, 30 %vol TBP and 10 mM CyMe4-BTBP, system 2: 70 %vol FS-13 and 30 %vol TBP, system 3: 100 %vol FS-13 and 10 mM CyMe4-BTBP and system 4: pure FS-13. In all cases 4 M HNO3 was used as aqueous phase. In system 1 all actinides were extracted and separated from the lanthanides. In both system 2 and 3 mainly U and Pu were extracted. In system 4 none of the metals were extracted.
26.	Halleröd, Jenny, 1987, et al. (author) Stability of phenyl trifluoromethyl sulfone as diluent in a grouped actinide extraction process 2015 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 304:1, s. 287-291 Journal article (peer-reviewed)abstract In this work, stability experiments have been performed on a phenyl trifluoromethyl sulfone based solvent containing 6,6'-bis(5,6-dialkyl-[1,2,4-]triazin-3-yl)-2,2'-bipyridine and tri-butyl phosphate. This solvent is intended to be used in a grouped actinide extraction process for partitioning and transmutation purposes. The distribution ratio for americium was determined to approximately 20 and for europium approximately 0.26 giving a separation factor of 77. The solvent maintain good distribution ratios and separation factors during both gamma irradiation of 6.6 kGy h(-1) for up to 24 h and acid contact for up to 6 weeks at room temperature.
27.	He, Peng, et al. (author) Radioactive I-129 in surface water of the Celtic Sea 2014 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 299:1, s. 249-253 Journal article (peer-reviewed)abstract Relatively large amounts of radioactive iodine 129I (T 1/2 = 15.7 Ma) have been documented in seawater such as the English Channel, the Irish Sea and the North Sea. Data on the concentration of the iodine isotopes in waters of the Celtic Sea are missing. Aiming to provide first 129I data in the Celtic Sea and compare them with levels in the other close-by seawater bodies, surface seawater samples were analyzed for the determination of 127I and 129I concentrations. The results revealed a high level of 129I in these waters and suggest strong influence by liquid discharges from La Hague and Sellafield reprocessing facilities. 127I concentrations are rather constant while the 129I/127I ratio reaches up to 2.8 × 10−8 (ranging from 10−10 to 10−8), which is 2–4 orders of magnitude higher than pre-nuclear era natural level. Transport of 129I to the Celtic Sea is difficult to depict accurately since available data are sparse. Most likely, however, that discharges originated from La Hague may have more influence on the Celtic Sea 129I concentrations than the Sellafield. Comprehensive surface water and depth profiles 129I data will be needed in the future for assessment of environmental impact in the region.
28.	He, Peng, et al. (author) Tracing variability in the iodine isotopes and species along surface water transect from the North Sea to the Canary Islands 2016 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 307:2, s. 1407-1412 Journal article (peer-reviewed)abstract A complete transect of surface water samples from the North Sea to the Canary Islands was collected during a continuous period in 2010. The samples were analyzed for total I-129 and I-127 isotopes and their iodide and iodate species. The results indicate a large variability in the total I-129 and its species along the transect, whereas less change and variation are observed for the total I-127 and its species. Transport of I-129 fromthe western English Channel via Biscay Bay is the main source of I-129 in the northeastern Atlantic Ocean.
29.	Hedström, Hanna, 1983, et al. (author) A study of the Arrhenius behavior of the co-precipitation of radium, barium and strontium sulfate 2013 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 298:2, s. 847-852 Journal article (peer-reviewed)abstract Co-precipitation of radium, barium and strontium is an important process in many contexts, such as uranium mining, oil extraction and in the safety assessment of a final repository for used nuclear fuel. Co-precipitation to a solid solution is possible since radium, barium and strontium act as chemical analogues. In this work the co-precipitation of radium, barium and strontium was studied and the kinetic behavior of the co-precipitation process was investigated. It was shown that radium, barium and strontium co-precipitate congruently and that the precipitation followed an Arrhenius behavior and the Arrhenius parameters for the systems was determined. When studying the differences of the Arrhenius constants by using a student t test (95 % confidence interval) it was observed that the only significant difference in the activation energy, E (a), is between radium and barium and between radium and strontium respectively, the pure strontium having the larger activation energy in comparison. This is most likely coupled to the metal ion size; since the hydration waters are more strongly bound, which leads to them having a slower exchange rate, which in turn effects the rate of co-precipitation to the metal these reactions will be slower.
30.	Ho, Doris M.L., et al. (author) Overall approaches and experiences of first-time participants in the Nuclear Forensics International Technical Working Group’s Fourth Collaborative Material Exercise (CMX-4) 2018 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 315:2, s. 353-363 Journal article (peer-reviewed)abstract The Fourth Collaborative Material Exercise (CMX-4) of the Nuclear Forensics International Technical Working Group (ITWG) registered the largest participation for this exercise in nuclear forensics, with seven of the 17 laboratories participating for the first time. Each of the laboratories had their strategic role to play in its respective country, analyzing real-world samples using their in-house resources. The scenario was fictitious but was thoughtfully crafted to engage participants in nuclear forensic investigations. In this paper, participants from five of the first-time laboratories shared their individual experience in this exercise, from preparation to analysis of samples.
31.	Insulander Björk, Klara, 1982, et al. (author) Effect of the thorium oxide content on the leaching of a mixed thorium-uranium oxide fuel 2022 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 331, s. 2849-2857 Journal article (peer-reviewed)abstract Leaching of uranium from uranium oxide fuel in contact with water can be a radiation hazard problem in the case of fuel cladding failure, either during nuclear reactor operation or in an interim storage, as well as in a final repository. One way to mitigate this is to reduce the solubility of the fuel matrix by the mixing uranium oxide with a compound which is less soluble but otherwise of similar properties. In this paper, the effect of thorium oxide content on the leaching of the uranium oxide matrix is investigated. The method was to study the leaching of the uranium oxide fuel matrix as a function of a varying content of thorium oxide, using materials manufactured by powder co-milling. It was found that the substitution of more than 25% UO2 with ThO2 reduces the matrix leaching by more than one order of magnitude in most of the different leaching solutions investigated. The substitution of 7% UO2 with ThO2 results in a reduction of matrix leaching by 10–90%, depending on the concentration of borate and dissolved oxygen in the leaching solution.
32.	Johnsson, Anna, 1975, et al. (author) Bioligand-mediated partitioning of radionuclides to the aqueous phase 2008 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 277:3, s. 637-644 Journal article (peer-reviewed)abstract The aqueous-phase partitioning of 59Fe, 147Pm, 234Th and 241Am by complexing compounds from subsurface bacteria has previously been studied in the presence of quartz sand. In this study the aqueous-phase partitioning of pico- to submicromolar amounts of 59Fe, 147Pm, 234Th and 241Am was analyzed in the presence of TiO2 and exudates from three species of subsurface bacteria: Pseudomonas fluorescens, Pseudomonas stutzeri, and Shewanella putrefaciens. All were grown under aerobic conditions and P. stutzeri and S. putrefaciens were grown under anaerobic conditions as well. The supernatants of the aerobic and anaerobic cultures were collected and radionuclide was added. TiO2, with BET surface area of 49.9 m2·g-1, was added to the supernatant radionuclide mix, and the pH was adjusted to approximately 8. After incubation, the amount of radionuclide in the liquid phase of the samples and controls was analyzed using scintillation method. Two types of values were calculated: solution% = the activity maintained in solution relative to the total activity, and Q-values = the quotient between the activity in samples and the activity in controls. Aerobic supernatants had solution% values between 89% and 100% for 59Fe and between 18 and 43% for 234Th. The solution% values for 241Am and 147Pm were less than 2% overall, but the Q-values were between 34 and 115 times more 241Am in bacterial supernatants than in controls. The corresponding values for 147Pm ranged from 6 to 20 times more than in the control. The solution% values for all elements in the presence of anaerobic supernatants were below 2%, but the Q-values clustered around 7 for 59Fe and ranging from 2 to 29 for 234Th, indicated that anaerobic supernatants partitioned these elements to the aqueous phase. Both aerobic and anaerobic supernatants tested positive for complexing compounds when analyzed, using the Chrome Azurol S assay. Complexation with excreted organic ligands is most likely the reason for the higher amounts of metals in samples than in the controls. Hence, aerobically and anaerobically excreted organic ligands seem able to influence the mobility of radionuclides in aerobic and anaerobic environments contaminated with these compounds.
33.	Johnsson, Anna, 1975, et al. (author) Leaching of spent nuclear fuel in the presence of siderophores 2009 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 279:2, s. 619-626 Journal article (peer-reviewed)abstract Metal species that are dissolved in water can be transported in the environment, because they can be mobile. Microorganisms can affect metal mobility by excreting organic ligands with high metal affinity. Siderophores are organic ligands with high affinities for Fe 3+ . They are also able to form complexes with other metals such as actinides. Many countries plan to deposit spent nuclear fuel in deep geological repositories. Microorganisms are present in these subterranean environments and could potentially affect the repository. In this study, the effect of microbial siderophores on the dissolution behavior of two fragments of a spent nuclear fuel pellet was investigated. The commercial hydroxamate siderophore, deferoxamine mesylate (DFAM), and pyoverdin siderophores, isolated from cultures of Pseudomonas fluorescens (CCUG 32456A), were used. DFAM and lyophilized pyoverdins were dissolved in synthetic groundwater to final concentrations of 10 μM and 2.5·10 -2 g·L -1 , respectively. The fuel pellet fragments were kept in sealed pressure vessels at 10 bars of H 2 . The pyoverdin solution was first tested, followed by the DFAM solution and the pure synthetic groundwater. Samples were taken on 0, 1, 5, 9 and 14 days after changing the solution in the pressure vessels. The elemental composition of samples was analyzed by means of ICP-MS. The pyoverdin solution maintained significantly higher concentrations of Np and Pu than the pure synthetic groundwater. On the 14 th day the concentrations of Np and Pu in the pure synthetic groundwater were 0.01 nM and 0.13 nM, respectively, compared to 0.02 nM and 0.31 nM in the pyoverdin solution. Furthermore, spent nuclear fuel samples were observed to release Ru in the presence of both pyoverdin and DFAM. Hence, it seems that siderophores can form complexes with elements present in spent nuclear fuel. © 2008 Akadémiai Kiadó.
34.	Jonsson, S., et al. (author) Experimental validation of corrections factors for gamma-gamma and gamma-X coincidence summing of Ba-133, Eu-152, and Sb-125 in volume sources 2020 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 323:1, s. 465-472 Journal article (peer-reviewed)abstract True coincidence summing correction factors for Ba-133, Eu-152 and Sb-125 were determined experimentally for a small volume source and compared with correction factors obtained with three softwares (EFFTRAN-X, GESPECOR and VGSL). The radionuclides investigated have a relatively challenging decay scheme and their spectra are known to suffer from losses due to summation (gamma-gamma, gamma-X and X-X) when measured at close distances on a HPGe detector sensitive to low energy photons. This study shows that the softwares were in good agreement with each other and the experimental data and the calculated activity was consistent with the activity in the volume source.
35.	Jonsson, S., et al. (author) Implementation of calculation codes in gamma spectrometry measurements for corrections of systematic effects 2015 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 303:3, s. 1727-1736 Journal article (peer-reviewed)abstract Four calculation codes were implemented on experimental data to calculate corrections of common systematic effects within high resolution gamma spectrometry. The detector parameters were sparsely optimized to imitate the usage that can be expected from personnel with limited experience. The transfer of the efficiency from the calibration geometry (60 ml, density 1.0 g/cm(3)) to 200 ml geometry (density 1.5 g/cm(3)) failed with all codes, which was discouraging. However, a majority of the other corrected activities deviated with less than 10 % from the reference activity values, even for density corrections or when corrections had been calculated for new source-detector-geometries. Smaller deviations, around 5 % or less, were achieved when corrections were done within the calibrated geometry. This shows a robustness of the calculation codes even if the in-data is not perfectly optimized.
36.	Kajan, Ivan, 1984, et al. (author) Effect of nitrogen compounds on transport of ruthenium through the RCS 2017 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 311:3, s. 2097-2109 Journal article (peer-reviewed)abstract Ruthenium is a fission product that can be released from the fuel in case of a severe nuclear accident. In this work the impact of the atmosphere composition, including air radiolysis products, on the transport of ruthenium through a primary circuit was examined. Experiments were performed at temperatures 1300, 1500 and 1700 K in a slightly humid air. In the experiments significant effect of nitrogen oxides (N2O, NO2) and nitric acid on the ruthenium chemistry in the model primary circuit was observed. The obtained results indicate a strong effect of air radiolysis products on the quantity partitioning of transported ruthenium to gaseous and aerosol compounds.
37.	Kajan, Ivan, 1984, et al. (author) Impact of gamma radiation on the ruthenium deposited materials in a nuclear power plant 2016 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 309:2, s. 743-749 Journal article (peer-reviewed)abstract © 2016 Akadémiai Kiadó, Budapest, Hungary During a severe nuclear accident ruthenium can form deposits on various surfaces inside the containment building in the form of ruthenium dioxide. Oxidizing air radiolysis products can interact with these deposits and volatilize ruthenium into the form of radiotoxic RuO4. The scope of this study was the gamma radiation induced re-vaporization of ruthenium from deposits on various materials representing surfaces inside the containment building. It was shown that humidity had an effect on the re-vaporization rates of ruthenium from epoxy paint. Some corrosion of various ruthenium deposited metal samples after gamma irradiation was also observed.
38.	Kim, CK, et al. (author) Pu-240/Pu-239 atom ratios in the bottom sediments of the NW Pacific Ocean 2003 In: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731 .- 1588-2780. ; 258:2, s. 265-268 Journal article (peer-reviewed)abstract Pu239+240 concentrations and Pu-240/Pu-239 atom ratios in bottom sediments of the Yellow Sea, Korea Strait, East Sea (Sea of Japan), Sea of Okhotsk, and Northwest Pacific Ocean were determined. In coastal sediments near the Korean Peninsula, Pu239+240 concentrations varied from 0.02 to 1.72 Bq.kg(-1), and their Pu-240 /Pu-239 atom ratios from 0.15 to 0.24, with an average of 0.20+/-0.03. Pu-240/Pu-239 atom ratios of bottom sediments in the deep NW Pacific Ocean and its marginal seas(East,Okhotsk seas) were in the range of 0.15-0.23. A little elevated Pu-240/Pu-239 atom ratios in the bottom layer sediment may be due to Pu released into the environment during the pre-moratorium period, having high Pu-240 /Pu-239 atom ratios and low Pu-238/Pu239+240 activity ratios.
39.	Korsakov, M. V., et al. (author) Feasibility of isotopic exchange in system [125I] iodide – undecahydro-iodo-closo-dodecaborate (2-) anion 2003 In: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731 .- 1588-2780. ; 256:1, s. 67-71:256, s. 67-71 Journal article (peer-reviewed)
40.	Kristo, Michael J., et al. (author) The application of radiochronometry during the 4th collaborative materials exercise of the nuclear forensics international technical working group (ITWG) 2018 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 315:2, s. 425-434 Journal article (peer-reviewed)abstract In a recent international exercise, 10 international nuclear forensics laboratories successfully performed radiochronometry on three low enriched uranium oxide samples, providing 12 analytical results using three different parent-daughter pairs serving as independent chronometers. The vast majority of the results were consistent with one another and consistent with the known processing history of the materials. In general, for these particular samples, mass spectrometry gave more accurate and more precise analytical results than decay counting measurements. In addition, the concordance of the U-235-Pa-231 and U-234-Th-230 chronometers confirmed the validity of the age dating assumptions, increasing confidence in the resulting conclusions.
41.	Lakosi, L., et al. (author) Gamma spectrometry in the ITWG CMX-4 exercise 2018 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 315:2, s. 409-416 Journal article (peer-reviewed)abstract Low enriched uranium samples of unknown origin were analyzed by 16 laboratories in the context of a Collaborative Materials Exercise (CMX), organized by the Nuclear Forensics International Technical Working Group (ITWG). The purpose was to compare and prioritize nuclear forensic methods and techniques, and to evaluate attribution capabilities among participants. This paper gives a snapshot of the gamma spectrometric capabilities of the participating laboratories and summarizes the results achieved by gamma spectrometry.
42.	Liljenzin, Jan, 1936, et al. (author) Preparation of radioactive enantiomers of amino acids using labelled racemates only 1988 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 126:3, s. 199-204 Journal article (peer-reviewed)
43.	Lundberg, Daniel (author) An overview of eight- and nine-coordinate N-donor solvated lanthanoid(III) and actinoid(III) ions 2018 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 316, s. 849-854 Journal article (peer-reviewed)abstract The use of replacement lanthanoid ions in actinoid chemistry is commonplace, which requires a full understanding of the similarities and differences between the two series. This overview lists, compares and discusses the available crystallographic data for N-donors for the lanthanoids and the actinoids using their trivalent state as a natural starting point for comparison.
44.	Lyseid Authen, Thea, 1993, et al. (author) A comparison on the use of DEHBA or TBP as extracting agent for tetra- and hexavalent actinides in the CHALMEX Process 2022 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 331:12, s. 5137-5145 Journal article (peer-reviewed)abstract The Chalmers Grouped ActiNide EXtraction process is a solvent extraction process for the homogeneous recycling of spent nuclear fuel. The use of TBP for the extraction of tetra- and hexavalent actinides can be problematic for several reasons, including troublesome degradation products causing crud formation, decreased extraction yield and the possibility of explosive red oil reactions. Here, the substitution of TBP by a N,N-dialkyl monoamide, DEHBA, is investigated. The findings suggest that DEHBA can be a suitable extracting agent for use in the CHALMEX solvent, although identified drawbacks need to be further investigated.
45.	Löfström Engdahl, Elin, 1983, et al. (author) A reinterpretation of C5-BTBP extraction data, performed in various alcohols 2013 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 296:2, s. 733-737 Journal article (peer-reviewed)abstract The separation of trivalent actinides from trivalentlanthanides present in used nuclear fuel can beachieved by using solvent extraction and the BTBP class ofligands. This separation is relevant for the advancedreprocessing of the used fuel. The choice of diluents insuch BTBP based systems has shown to affect the extractionas well as the separation. Long chained alcohols havepreviously been investigated as such diluents, showing thatthe americium extraction is higher into alcohols havingshorter chains (hexanol, and heptanol) than in longerchained ones (nonanol and decanol). In this work it isshown that not only the distribution ratio, but also thecontact time needed before reaching extraction equilibriumis shorter when using shorter chain length of the alcoholdiluent. It is also shown that the rate of extraction can becorrelated to the interfacial tension between the diluent andthe aqueous phase. A low interfacial tension gives a fastextraction while an extraction system with higher interfacialtension needs a longer time of phase contact in order toreach extraction equilibrium.
46.	Löfström Engdahl, Elin, 1983, et al. (author) Hexanoic acid as an alternative diluent in a GANEX process: feasibility study 2014 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 290:3, s. 1261-1266 Journal article (peer-reviewed)abstract Used nuclear fuel is radiotoxic for mankind andits environment for a long time. However, if it can betransmuted, the radiotoxicity as well as its heat load arereduced. Before a transmutation the actinides within theused fuel need to be separated from the fission, corrosionand activation products. This separation can be achieved byusing the liquid–liquid extraction technique. One extractionprocess that can be used for such a separation is the GroupActiNide EXtraction (GANEX) process. One GANEXprocess that can successfully accomplish the separationutilizes the diluent cyclohexanone in combination with theextractant tributylphosphate (TBP) (30 % vol) and a secondextractant, CyMe4-BTBP (10 mM). However, thereare some issues when using cyclohexanone as diluent. Inthis work an alternative diluent has therefore been tried inorder to determine if it can replace cyclohexanone. Thediluent used was hexanoic acid. In a system containing10–12 mM CyMe4-BTBP and 30 % vol TBP in hexanoicacid with the aqueous phase 4 M HNO3, the distributionratios for americium and curium are unfortunately low(DAm = 1.1 ± 0.27, DCm = 1.6 ± 1.81). The concentrationof CyMe4-BTBP ligand, the extractant of curium andamericium, could unfortunately not be increased, becauseof limited solubility in hexanoic acid. The distributionratios for fission, corrosion and activation products werelow for most metals; however, cadmium, palladium andmolybdenum all unfortunately have distributions ratiosabove 1. To conclude, low americium and curium extractionsindicate that hexanoic acid is not a suitable diluentwhich could replace cyclohexanone in a GANEX process
47.	Löfström Engdahl, Elin, 1983, et al. (author) Purification of used scintillation liquids containing the alpha emitters americium and plutonium 2015 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 303:2, s. 1133-1136 Journal article (peer-reviewed)abstract In Sweden, alpha radioactive waste liquids withan activity over some kBq per waste container cannot besent for final storage. Therefore, in this work, a method fora purification of alpha active scintillation cocktails wasdeveloped. Until today (March, 2013) more than 20 L ofscintillation liquids have successfully been purified fromamericium and plutonium. The products of the process area solid fraction that can be sent to final storage and apractically non-radioactive liquid fraction that can be sentto municipal incineration.
48.	Magnusson, Åsa, et al. (author) C-14 in spent ion-exchange resins and process water from nuclear reactors – A method for quantitative determination of organic and inorganic fractions 2008 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 275:2, s. 261-273 Journal article (peer-reviewed)abstract A method of separately quantifying organic and inorganic 14C compounds present in spent ion-exchange resins and process water from nuclear power reactors has been developed. Extraction of carbon compounds is accomplished by means of acid stripping (inorganic 14C) and subsequent wet oxidation (organic 14C) or by N2 purging in combination with a catalytic furnace (oxidized and reduced gaseous compounds) with organic and inorganic 14C species collected separately. Recovery experiments on simulated samples spiked with 14C-labeled sodium carbonate, sodium acetate and sodium formate, showed extraction yields of 94–98%. The sample-specific procedures were also tested on authentic samples of spent resins and reactor water with good results. Validation and reliability of the procedures are presented and the method is compared to previous methods reported in the literature.
49.	Mantero, Juan, et al. (author) Quality assurance via internal tests in a newly setup laboratory for environmental radioactivity 2019 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 322:2, s. 891-900 Journal article (peer-reviewed)abstract The present work shows one way to apply inner Control Tests to produce reliable results based on (a) the combination of different techniques (alpha vs. Gamma spectrometry, alpha spectrometry vs. ICP-MS or gamma spectrometry vs. XRF) and (b) on the performance of inter-comparison exercises with another laboratory with a wider experience in the field.
50.	Matyskin, Artem, 1989, et al. (author) Disassembly of old radium sources and conversion of radium sulfate into radium carbonate for subsequent dissolution in acid 2016 In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 310:2, s. 589-595 Journal article (peer-reviewed)abstract In this work details of safe radium source disassembly which were previously used in brachytherapy are described and different methods for conversion of RaSO4 into aqueous solution are reviewed. The method of choice included three cycles of RaSO4 heating in 1.5 M Na2CO3 up to 85 °C, cooling and subsequent removal of supernatant. X-ray diffraction study showed that the method allows the synthesis of, presumably, amorphous RaCO3, which can be dissolved in mineral acid. Gamma spectrometric measurements showed that most of the initial RaSO4 was converted into solution and that 7 ± 1 % of the initial 210Pb was co-precipitated with RaCO3.

Skapa referenser, mejla, bekava och länka

Permalink

Träfflista för sökning "L773:0236 5731 OR L773:1588 2780 "

Refine your search

Year