| 1. |
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| 2. |
- Brown, Paul, et al.
(författare)
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Solubility of Radium and Strontium Sulfate across the Temperature Range of 0 to 300℃
- 2014
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Ingår i: Uranium Mining and Hydrogeology 2014. - 9783319110592 ; , s. 553-563
-
Konferensbidrag (refereegranskat)abstract
- Solubility constant data for radium and strontium (celestite) sulfate has been determined across the temperature range of 0 to 300℃ based on the available literature data for these two phases as well as similar data for calcium (anhydrite) and barium (barite) sulfate for which solubility constant data is available acrossthe same temperature range. The thermodynamic data for the phases have been determined by assuming that the solubility constants are a function of the inverse ofabsolute temperature with a constant, but non-zero, heat capacity change. The solubility for all phases shows a peak with respect to temperature, with the temperature at which the peak occurs increasing as the alkaline earth metals become heavier. The heat capacity change is a function of the ionic radius of the alkaline earth metal ion whereas the enthalpy of reaction at 25℃ is related to the peak at which the maximum solubility occurs. The entropy of reaction at 25℃ is related to the solubility constant and the derived enthalpy of reaction at that temperature.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Hansson, Niklas, 1992, et al.
(författare)
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Geometrical aspects of alpha dose rates from UO2 based fuels
- 2022
-
Ingår i: Radiation Physics and Chemistry. - : Elsevier BV. - 0969-806X .- 1879-0895. ; 199, s. 110336-
-
Tidskriftsartikel (refereegranskat)abstract
- Models for calculating dose rates of spherical particles as well as in fuel cracks are important for radionuclide source term estimations. Dose rates from UO2 based fuels were calculated for planar, spherical, and crack geometries. The escape probability for a-particles in spherical UO2 particles was derived as a continuous equation. The dose rate increased with increasing spherical radius due to the decreasing relative volume of the surrounding water layer. The model produced escape probabilities that were closely predicted by the theoretical derivation. It was shown that the dose rate in water filled fuel cracks with width smaller than the range of an alpha-particle led to dissolution rates that were lower per unit surface area.
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| 7. |
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| 8. |
- Hedström, Hanna, 1983, et al.
(författare)
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A study of the Arrhenius behavior of the co-precipitation of radium, barium and strontium sulfate
- 2013
-
Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 298:2, s. 847-852
-
Tidskriftsartikel (refereegranskat)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.
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| 9. |
- Hedström, Hanna, 1983, et al.
(författare)
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Radon capture with silver exchanged zeolites
- 2012
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Ingår i: Radiochimica Acta. - : Walter de Gruyter GmbH. - 0033-8230 .- 2193-3405. ; 100:6, s. 395-399
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Tidskriftsartikel (refereegranskat)abstract
- To enable laboratory work with larger amounts of Ra-226 and its decay products, e.g., Rn-222 and its daughters, these need to be captured in order to avoid unnecessary alpha contamination of the laboratory work space and ventilation systems. In this study, radon gas was pumped through a column filled with the silver exchanged zeolite called "silver exchanged molecular sieves 13X" (Ag84Na2[(AlO2)(86)(SiO2)(106)]. xH(2)O). After exposure to radon, the radioactivity of the zeolite was measured repeatedly using high resolution gamma spectrometry. It was shown that radon was captured and retained in the silver exchanged zeolite. The zeolites' ability to retain radon was decreased by formation of metallic silver, caused by ionizing radiation. However, the zeolite was regenerated by heating and its radon capture ability was restored. The daughters of radon are not in gas phase and will hence stay on the column.
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| 10. |
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| 11. |
- Kajan, Ivan, 1984, et al.
(författare)
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Impact of Ag and NOx compounds on the transport of ruthenium in the primary circuit of nuclear power plant in a severe accident
- 2017
-
Ingår i: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 100, s. 9-19
-
Tidskriftsartikel (refereegranskat)abstract
- Ruthenium is a semi-volatile element originating as a fission product in nuclear reactors that can be released in case of a severe nuclear accident. In this work, the impact of atmosphere composition on the transport of ruthenium through the primary circuit was examined. The effects of silver nanoparticles representing aerosols and NO2 gas as a product of air radiolysis were studied. Quantification of ruthenium transported both as gas and aerosol was performed. Chemical composition of ruthenium species was evaluated. The transport of gaseous ruthenium through the facility increased significantly when NO2 gas was fed into the atmosphere. When both silver aerosols and NO2 were fed into the atmosphere, the transport of ruthenium in gaseous and aerosol forms was promoted. It was concluded that the composition of atmosphere in the primary circuit will have a notable effect on the speciation of ruthenium transported into the containment building during a severe accident and thus on the potential radioactive release to the environment.
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| 12. |
- Kärkelä, T, et al.
(författare)
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Nordic Collaboration: Impact of Ag and NOx Compounds on the Transport of Ruthenium in the Primary Circuit of NPP in a Severe Accident
- 2016
-
Ingår i: 25th International Conference Nuclear Energy for New Europe, (Nene 2016); proccedings eds. Snoj, L; Lengar, I.. - 9789616207409 ; , s. no. 802-
-
Konferensbidrag (refereegranskat)abstract
- When ruthenium is released from the fuel as ruthenium oxides to the environment in a severe NPP accident, ruthenium isotopes Ru-103 and Ru-106 cause a radiotoxic risk to the population both in a short and long term. As the previous international studies on the transport of ruthenium in the reactor coolant system (RCS) have mainly been conducted in pure air-steam atmospheres, the current study was dedicated to air ingress conditions with representative airborne air radiolysis (NOx) and control rod (Ag) species which were mixed with vaporized Ru oxides. The aim was to study the impact of these additives on the transport of ruthenium as gas and particles through the primary circuit of nuclear power plant in a severe accident. As a main outcome, the transport of gaseous ruthenium through the facility increased significantly when the oxidizing NO2 gas was fed into the atmosphere.
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| 13. |
- Matyskin, Artem, 1989, et al.
(författare)
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Crystal structure of radium sulfate: An X-ray powder diffraction and density functional theory study
- 2017
-
Ingår i: Journal of Solid State Chemistry. - : Elsevier BV. - 0022-4596 .- 1095-726X. ; 253, s. 15-20
-
Tidskriftsartikel (refereegranskat)abstract
- Radium-barium sulfate (Ra0.76Ba0.24SO4) powder was examined using X-ray Diffraction (XRD) technique and its crystal structure was optimized using Density Functional Theory (DFT). XRD data show that radium and barium sulfate form a solid solution and that Ra0.76Ba0.24SO4 is orthorhombic and isostructural with pure RaSO4, barite (BaSO4), celestite (SrSO4) and anglesite (PbSO4), crystallizing in the space group Pmna (No. 62). The unit cell parameters of the Ra0.76Ba0.24SO4 crystal have been determined using Rietveld refinement and were extrapolated to unit cell parameters of the pure RaSO4 phase using Vegard's law: a=9.129(8), b=5.538(3), c=7.313(5) Å. DFT geometry optimization was used to derive atomic coordinates and interatomic distances in both Ra0.76Ba0.24SO4 and pure RaSO4. The experimental and DFT geometry optimization results obtained in this work are in good agreement with each other, and furthermore with literature data.
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| 14. |
- Matyskin, Artem, 1989, et al.
(författare)
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Disassembly of old radium sources and conversion of radium sulfate into radium carbonate for subsequent dissolution in acid
- 2016
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 310:2, s. 589-595
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Tidskriftsartikel (refereegranskat)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.
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| 15. |
- Ramebäck, Henrik, 1967, et al.
(författare)
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A laboratory exercise on systematic effects in gamma ray spectrometry
- 2015
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 304:1, s. 467-471
-
Tidskriftsartikel (refereegranskat)abstract
- A laboratory exercise for calculation of true coincidence summing correction factors as well as calculating the effect of deviations between sample and standard source (filling height) was developed. This laboratory exercise was held in a masters course in nuclear chemistry the first time during fall 2013. The aim of the exercise was to high-light the importance of correcting for biases due to different systematic effects in gamma spectrometric measurements.
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| 16. |
- Ramebäck, Henrik, 1967, et al.
(författare)
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A Monte Carlo method for calculation of the characteristic limits decision threshold and detection limit in low-level radioactivity measurements
- 2021
-
Ingår i: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043 .- 1872-9800. ; 178
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, calculation of decision threshold and detection limit expressed in counts for low-level radioactivity measurements were evaluated and compared to a Monte Carlo method for the case of paired Poisson-distributed observations, i.e. for discrete variables. The calculated characteristic limits obtained from Monte Carlo calculations were compared with analytical expressions given in literature. The results in this study show that the equations given by Currie are in good agreement with the results from the Monte Carlo calculations simulating nuclear counting applications with a low number of observed counts. An exception is observed for a background corresponding to zero counts. This study also shows that at a low number of counts, the specific boundary conditions of the interval that represents counts corresponding to the presence of the analyte (>or ≥), have an impact on the false positives and negatives rates as defined by the parameters α and β.
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| 17. |
- Ramebäck, Henrik, 1967, et al.
(författare)
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Calculation of decision threshold and detection limit in radiometric measurements using a Monte Carlo Method
- 2020
-
Ingår i: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043 .- 1872-9800. ; 156
-
Tidskriftsartikel (refereegranskat)abstract
- Calculation of the decision threshold and detection limit of a measurement, or measurement method, are crucial in order to decide if an analyte is present or not and with what confidence it can be quantified. That decision is important in view of possible actions if something would be detected. In this work, a method for calculating these limits using a Monte Carlo method is presented. In the Monte Carlo method any a priori distribution (e.g. normal distribution, rectangular distribution, triangular distribution) of an input quantity can be selected. Differences between the Monte Carlo calculated characteristic limits and the ones calculated according to ISO 11929:2010 is presented. Moreover, suggestions how to calculate the detection limit when it can not be calculated according to the ISO 11929:2010 are given.
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| 18. |
- Ramebäck, Henrik, 1967, et al.
(författare)
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The jackknife as an approach for uncertainty assessment in gamma spectrometric measurements of uranium isotope ratios
- 2010
-
Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 268:16, s. 2535-2538
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Tidskriftsartikel (refereegranskat)abstract
- The jackknife as an approach for uncertainty estimation in gamma spectrometric uranium isotope ratio measurements was evaluated. Five different materials ranging from depleted uranium (DU) to high enriched uranium (HEU) were measured using gamma spectrometry. High resolution inductively coupled plasma mass spectrometry (ICP-SFMS) was used as a reference method for comparing the results obtained with the gamma spectrometric method. The relative combined uncertainty in the gamma spectrometric measurements of the U-238/U-235 isotope ratio using the jackknife was about 10-20% (k = 2), which proved to be fit-for-purpose in order to distinguish between different uranium categories. Moreover, the enrichment of U-235 in HEU could be measured with an uncertainty of 1-2%. (C) 2010 Elsevier B.V. All rights reserved.
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| 19. |
- Ramebäck, Henrik, 1967, et al.
(författare)
-
Uncertainty assessment in gamma spectrometric measurements of plutonium isotope ratios and age
- 2012
-
Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 287, s. 56-59
-
Tidskriftsartikel (refereegranskat)abstract
- A method for the assessment of the combined uncertainty in gamma spectrometric measurements of plutonium composition and age was evaluated. Two materials were measured. Isotope dilution inductively coupled plasma sector field mass spectrometry (ID-ICP-SFMS) was used as a reference method for comparing the results obtained with the gamma spectrometric method for one of the materials. For this material (weapons grade plutonium) the measurement results were in agreement between the two methods for all measurands. Moreover, the combined uncertainty in all isotope ratios considered in this material (R-Pu238/Pu239, R-Pu240/Pu239, R-Pu241/Pu239, and R-Am241/Pu241 for age determination) were limited by counting statistics. However, the combined uncertainty for the other material (fuel grade plutonium) were limited by the response fit, which shows that the uncertainty in the response function is important to include in the combined measurement uncertainty of gamma spectrometric measurements of plutonium.
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| 20. |
- Torapava, Natallia, 1980, et al.
(författare)
-
Recrystallization of Ra-223 with barium sulfate
- 2014
-
Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 301:2, s. 545-553
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, the kinetics of barium sulfate recrystallization has been studied in acidic 0.01 mol dm -3 sodium sulfate solution using Ra-223 and Ba-133 tracers at very low total radium concentration, i. e. less than 10(-13) mol dm(-3). It was found that the system follows the homogeneous recrystallization model and that recrystallization rates, inferred by the decrease of Ra-223 and Ba-133 in the aqueous solution, are fast. Therefore, even at very low concentrations, below the solubility limit, radium will be retained by barium sulfate-a mineral present in the deep underground repository.
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| 21. |
- Vesterlund, Anna, 1980, et al.
(författare)
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Characterization of strong 241Am sources
- 2015
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Ingår i: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043 .- 1872-9800. ; 99, s. 162-167
-
Tidskriftsartikel (refereegranskat)abstract
- Gamma ray spectra of strong 241Am sources may reveal information about the source composition as there may be other radioactive nuclides such as progeny and radioactive impurities present. In this work the possibility to use gamma spectrometry to identify inherent signatures in 241Am sources in order to differentiate sources from each other, is investigated. The studied signatures are age, i.e. time passed since last chemical separation, and presence of impurities. The spectra of some sources show a number of Doppler broadened peaks in the spectrum which indicate the presence of nuclear reactions on light elements within the sources. The results show that the investigated sources can be differentiated between by age and/or presence of impurities. These spectral features would be useful information in a national nuclear forensics library (NNFL) in cases when the visual information on the source, e.g. the source number, is unavailable.
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| 22. |
- Vesterlund, Anna, 1980, et al.
(författare)
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Characterization of strong 241Am sources
- 2014
-
Ingår i: International Conference on Advances in Nuclear Forensics: Countering the Evolving Threat of Nuclear and Other Radioactive Material out of Regulatory Control, Vienna, IAEA; 07/2014.
-
Konferensbidrag (refereegranskat)
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| 23. |
- Vesterlund, Anna, 1980, et al.
(författare)
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On the categorization of uranium materials using low resolution gamma ray spectrometry
- 2013
-
Ingår i: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043 .- 1872-9800. ; 73, s. 54-57
-
Tidskriftsartikel (refereegranskat)abstract
- In order to characterize uranium materials during e.g. nuclear safeguards inspections and in initial stages of nuclear forensic investigations, hand-held low resolution gamma ray detection instruments with automatic uranium categorization capabilities may be used. In this paper, simulated response curves for a number of matrices applied on NaI(Tl) scintillation detector spectra show that the result of the categorization is strongly dependent on the physical properties of the uranium material. Recommendations on how to minimize the possibility of misclassification are discussed.
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| 24. |
- Vieceli, Nathalia Cristine, 1989, et al.
(författare)
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Recycling of Li-Ion Batteries from Industrial Processing: Upscaled Hydrometallurgical Treatment and Recovery of High Purity Manganese by Solvent Extraction
- 2023
-
Ingår i: Solvent Extraction and Ion Exchange. - : Informa UK Limited. - 0736-6299 .- 1532-2262. ; 41:2, s. 205-220
-
Tidskriftsartikel (refereegranskat)abstract
- Manganese plays a central role in lithium-ion batteries (LIBs) but its recycling is rarely addressed when compared to other valuable metals present in LIBs, such as Co and Ni. Thus, the main goal of this work was to study and achieve the separation of Mn from Co and Ni by solvent extraction from a leachate obtained from LIBs using hydrochloric acid in an upscaled reactor, which is an innovative aspect of this work. The results confirmed the high selectivity of D2EHPA towards Mn, which could be completely extracted in two stages (0.5 M D2EHPA at pH 2.5). The main co-extracted metals were Al, Cu and Co, but with lower concentrations than Mn. The behavior of minor impurities such as Zn and Mg was also monitored. Scrubbing using manganese chloride was crucial to remove impurities from the loaded organic and prevent their presence in the stripping product, and high O:A ratios negatively affected the scrubbing efficiency. Keeping the concentration of HCl up to 0.5 M in the stripping stage helped to limit the stripping of impurities. Manganese oxide was precipitated as a product with 99.5% purity (with traces of Zn, Cu and Co), which could be reused in the battery value chain.
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| 25. |
- Vieceli, Nathalia Cristine, 1989, et al.
(författare)
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Solvent extraction of cobalt from spent lithium-ion batteries: Dynamic optimization of the number of extraction stages using factorial design of experiments and response surface methodology
- 2023
-
Ingår i: Separation and Purification Technology. - : Elsevier BV. - 1873-3794 .- 1383-5866. ; 307
-
Tidskriftsartikel (refereegranskat)abstract
- The optimization of lithium-ion batteries (LiBs) recycling is crucial not only from a waste management perspective but also to decrease the dependence on imports of critical raw materials. In addition, the diversification of the recycling technologies is very important for better flexibility of the market. This study aims at investigating the recovery of Co from spent LiBs using solvent extraction from a real chloride-based solution obtained after the removal of Mn, which is very rarely reported. Cyanex 272 was used as the extractant and the effect of several variables on the extraction efficiency was considered to model and optimize the separation of Co and Ni. The number of extraction stages directly affects not only the process efficiency but also its cost. Thus, in this work, a novel approach was developed to assist in the selection of the number of extraction stages using a dynamic method based on the factorial design of experiments and response surface methodology combined with the Kremseŕs Equation. This method can assist the process design, decrease the overall cost of the operation, and optimize the separation of Co and Ni in a reduced number of extraction stages. The concentration of Co and Ni in the feed solutions is ∼ 8.3 g/L and 1.9 g/L, respectively. Based on the results, 98% extraction efficiency for Co can be achieved in 1 to 2 extraction stages with low co-extraction of Ni (<5%) when using 0.6–0.8 M Cyanex 272, O:A ratio below 1 and pH ∼ 5, but several combinations of conditions could provide similar results.
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| 26. |
- Agrawal, Munmun, et al.
(författare)
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Global market trends of tantalum and recycling methods from Waste Tantalum Capacitors: A review
- 2021
-
Ingår i: Sustainable Materials and Technologies. - : Elsevier BV. - 2214-9937. ; 29
-
Forskningsöversikt (refereegranskat)abstract
- The rapid digitalization of the world, technological up-gradation, and shorten life cycle of electronic gadgets leading to the generation of an enormous amount of waste tantalum capacitors (WTCs) rich in tantalum every year. The need of the hour is to develop an effective way to recycle tantalum from these waste scraps considering the scarcity of tantalum, environmental impacts, resource and energy utilization, and lower recycling rates. In this paper, various existing methods of recovery of metallic tantalum from WTCs have been extensively reviewed. Processes have been examined in light of recovery efficiency, purity of the resultant product, process complexity, and limitations. The bottleneck in the recovery of tantalum from WTCs is the presence of tightly covered mold resin over the surface of the tantalum anode. Various researchers have recovered Ta with varying degrees of success. Pyrolysis, followed by chloride metallurgy, has been proven to be an effective technology on account of its high removal rate, resource and energy utilization, and lesser environmental impacts. This article also explores the global scenario of tantalum. Overall this review provides a foundation to understand the potential barrier and various opportunities associated with the recovery of tantalum from WTCs.
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| 27. |
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| 28. |
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| 29. |
- Allard, Stefan, 1968, et al.
(författare)
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Complexing Properties of α-Isosaccharinate: Stability Constants, Enthalpies and Entropies of Th-complexation with Uncertainty Analysis
- 2006
-
Ingår i: Journal of Solution Chemistry. - : Springer Science and Business Media LLC. - 0095-9782 .- 1572-8927. ; 25:8, s. 1173-1186
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Tidskriftsartikel (refereegranskat)abstract
- The complexation of Th-alpha-isosaccharinate has been examined using liquid-liquidextraction technique. An organic phase consisting of 0.025 M acetylacetone in toluene was used with a 1.0 M NaClO4 aqueous phase kept at pH 8 in a thermostated AKUFVE unit. Two temperatures, 15 degrees C and 35 degrees C, were investigated and the stability constants for the complexation reaction Th4+ + pISA Th(ISA(-))(p)((4-p)+) were determined by curve fitting of a distribution ratio equation to experimental data employing a chi(2) method to estimate the standard deviation. By incorporating data from a previous study at 25 degrees C, Delta H degrees and AS' for the reaction were also obtained, using randomly generated, binomially distributed, data points around the stability constant values with one standard deviation in two dimensions. Three alpha-isosaccharinate ligands were found to be involved in the complexation with thorium.
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| 30. |
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| 31. |
- Altmaier, M., et al.
(författare)
-
TALISMAN - A European Commission FP7 project promoting transnational access to large infrastructures for a safe management of actinides
- 2014
-
Ingår i: Plutonium Futures: The Science 2014; Las Vegas; United States; 7 September 2014 through 12 September 2014. - 9781510808089 ; , s. 165-166
-
Konferensbidrag (refereegranskat)abstract
- TALISMAN is a large international project funded within the European Commission FP7 EURATOM framework. The aim of TALISMAN is to offer transnational access to large infrastructures for a safe management of actinides. Although clearly focusing on R&D activities from European Union member states, TALISMAN is also open to participation from non-EU countries. TALISMAN is coordinated by CEA (contact by stephane.bourg@cea.fr), supported by a Governing Board and the ExCom. Dedicated studies on Pu containing materials are integral part of TALISMAN. Safety issues are of fundamental importance for the acceptance and sustainable application of nuclear energy. Actinides play a central role in the nuclear fuel cycle from mining, fuel fabrication, energy production, up to reprocessing, partitioning and transmutation treatment of used fuel, and finally the management and disposal of radioactive waste. Fundamental understanding of actinide properties and behavior in fuel materials during the separation processes and in geological repositories is an imperative prerequisite to tackle the related safety issues. Unravelling the complexity of the actinide components of used nuclear fuel certainly represents one of the great challenges in nuclear science. To meet the needs of safe and sustainable management of nuclear energy it is essential to maintain a high level of expertise in actinide sciences both on a European and international level. Educating and training the next generation of scientists and engineers who will contribute to developing safe actinide management strategies is a key mission. Because actinides are radioactive elements and handling requires specific safety measures, their study requires advanced tools and facilities that are only available to a limited extent. Only a few academic and research organisations have the capabilities and licenses to work on actinide elements. From a European perspective it is therefore strategic to coordinate the existing actinide infrastructures in Europe and strengthen the community of scientists working on actinides. Within TALISMAN we offer (for positively evaluated scientific research proposals submitted in reply to a specific TALISMAN call) access to the previous ACTINET Pooled Facilities (CEA Atalante and CEA DPC, France; ITU Laboratories & hot-cells, European Commission; KIT-INE laboratories and KIT-INE beamline, Germany; HZDR-IRE & ROBL, Germany; PSI microXAS Beamline, Switzerland) to which two new facilities have been added: NNL Central Lab in the UK and CHALMERS in Sweden. TALISMAN is also open to scientists and research organizations from outside the European Union. TALISMAN leads and coordinates a network of actinide facilities across Europe, but also manages a network between facilities and users to increase the knowledge for a safer management of actinides. TALISMAN also enhances the efforts made to support education and training issues by continuing the former ACTINET Summer School series and travel grant attributions for attending international conferences like the Plutonium Futures series. The TALISMAN project website is regularly updated and offers detailed information on all TALISMAN activities at http://www.talisman-project.eu. This is including contact addresses, TALISMAN newsletters, announcements and description of open and forthcoming calls for transnational user access and indicates several other options to perform actinide research within the TALISMAN context.
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| 32. |
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| 33. |
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| 34. |
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| 35. |
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| 36. |
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| 37. |
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| 38. |
- Andersson, Sofie, 1976, et al.
(författare)
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Study of nitrate complex formation with Pm, Eu, Am and Cm using a solvent extraction technique
- 2004
-
Ingår i: Radiochimica Acta. - : Walter de Gruyter GmbH. - 0033-8230 .- 2193-3405. ; 92:12, s. 863-867
-
Tidskriftsartikel (refereegranskat)abstract
- The separation of actinides and lanthanides is an important question in the treatment of spent nuclear fuel in the transmutation concept. To find an efficient and well functioning separation process it is necessary to study the chemistry of the elements in the two groups in different aqueous media. The stability constants of the nitrate complex formation with Pm, Eu, Am and Cm were determined using solvent extraction. The extraction was studied using the synergistic system of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine and 2-bromodecanoic acid in tert-butyl benzene. As the nitrate ion concentration in the aqueous phase was increased, a decrease in separation between actinides and lanthanides was seen owing to complex formation between the different elements and the nitrate ions.
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| 39. |
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| 40. |
- Aneheim, Emma, 1982, et al.
(författare)
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A TBP/BTBP-based GANEX Separation Process. Part 1: Feasibility
- 2010
-
Ingår i: Solvent Extraction and Ion Exchange. - : Informa UK Limited. - 0736-6299 .- 1532-2262. ; 28:4, s. 437-458
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Tidskriftsartikel (refereegranskat)abstract
- A GANEX (Group ActiNide EXtraction) separation system for transmutation has been developed. In this separation process the actinides should be extracted as a group from the lanthanides and the fission and corrosion/activation products. This can be achieved by combining BTBP (bis-triazine-bipyridine) with TBP (tri-butyl phosphate) in cyclohexanone. From 4M nitric acid this organic system extracts the actinides (log(DAm) = 2.19, log(DPu) = 2.31, log(DU) = 1.03, log(DNp) = 0.53) and also separates them from the lanthanides (log(DLa) = -2.0, log(DCe) = -1.72, log(DNd) = -1.05, log(DSm) = -0.18, log(DEu) = -0.02). One problem encountered is that some of the fission and corrosion products are also extracted. The new system however still looks feasible.
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| 41. |
- Aneheim, Emma, 1982, et al.
(författare)
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A TBP/BTBP-Based GANEX Separation Process Part 3: Fission Product Handling
- 2013
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Ingår i: Solvent Extraction and Ion Exchange. - : Informa UK Limited. - 0736-6299 .- 1532-2262. ; 31:3, s. 237-252
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Tidskriftsartikel (refereegranskat)abstract
- A Group ActiNide EXtraction (GANEX) separation system for transmutation has been developed, combining CyMe4-BTBP with TBP and cyclohexanone. This new GANEX solvent has proven efficient in actinide extraction but also been found to extract some undesired fission products and corrosion products. Three major fission products were primarily selected for the study: Mo, Zr, and Pd. There are three main strategies for handling the extraction problem, all of which have been investigated and discussed; these are Pre-extraction, Suppression, and Scrubbing. The only strategy that was found to control the behavior of all three main fission products was suppression by the combination of two water-soluble complexing agents bimet and mannitol.
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| 42. |
- Aneheim, Emma, 1982, et al.
(författare)
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A TBP/BTBP-based GANEX Separation ProcessPart 2: Ageing, Hydrolytic, and Radiolytic Stability
- 2011
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Ingår i: Solvent Extraction and Ion Exchange. - : Informa UK Limited. - 0736-6299 .- 1532-2262. ; 29:2, s. 157-175
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Tidskriftsartikel (refereegranskat)abstract
- The waste from nuclear power plants worldwide has to be isolated from man and his environment for about 100,000 years to equal the levels of natural uranium. If, however, the long-lived actinides could be separated from the spent fuel and transmuted, then the isolation time could be shortened to about 1,000 years. This does, however, require the selective separation of the actinides from the rest of the waste. Several processes exist for such a separation, of which one is the Group ActiNide Extraction (GANEX) process. A novel GANEX process has been developed at the Chalmers University of Technology utilizing the properties of already well known extractants by combining BTBP and TBP into one solvent. The stability provided by this GANEX solvent towards ageing, hydrolysis, and radiolysis has been investigated. The results show that the actinide distribution ratios are maintained after a long duration of contact with strong nitric acid. The solvent has also been found to be stable towards radiolysis up to 200 kGy in contact with 4 M nitric acid.
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| 43. |
- Aneheim, Emma, 1982, et al.
(författare)
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Aqueous complexation of palladium to prevent precipitation and extraction in a group actinide extraction system
- 2012
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Ingår i: Hydrometallurgy. - : Elsevier BV. - 0304-386X. ; 115, s. 71-76
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Tidskriftsartikel (refereegranskat)abstract
- It has recently been reported that a cyclohexanone based solvent containing the extractant, CyMe4-BTBP (BisTriazine,BiPyridine) together with tri-butyl phosphate intended for use in a GANEX (Group Actinide Extraction) process also extracts the fission product palladium. When cyclohexanone was used as a diluent it was also observed that without any extractant present in the organic phase, palladium rapidly formed a fine black precipitate of metallic palladium. In this work, two water soluble complexing agents were identified and found to be able to stabilize the palladium in 1 M nitric acid, preventing it from precipitating, namely the amino acid methionine and its derivative (25,2'S)-4,4'-(ethane-12-diylbis(sulfanediyl))bis(2-aminobutanoic acid) (bimet). Of these two, however, only bimet could reliably prevent the precipitation of palladium from the process aqueous solution (4 M nitric acid) and stop its extraction by the organic solvent. It was also found that an addition of bimet to the aqueous phase did not alter the actinide extraction by the GANEX solvent, thus making it a feasible candidate for masking the palladium extraction in a future process.
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| 44. |
- Aneheim, Emma, 1982, et al.
(författare)
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Development of a Novel GANEX Process
- 2010
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Ingår i: ACS Symposium Series. - Washington, DC : American Chemical Society. - 1947-5918 .- 0097-6156. ; 1046, s. 119-130
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Konferensbidrag (refereegranskat)abstract
- The waste from nuclear power plants has to be isolated from man and his environment for about 100,000 years to be considered safe. It has been suggested that if the long-lived actinides could be separated from the spent fuel and transmuted, the isolation time could be shortened to about 1,000 years. This, however, requires selective separation of parts of the waste. The partitioning for transmutation research in Europe has for the major part taken place within several European Union Framework Programmes. Within the projects NEWPART, PARTNEW and EUROPART a process scheme for the partitioning of nuclear waste from the PUREX process was developed. The scheme includes the DIAMEX, SANEX and SESAME-processes among which both the DIAMEX and SANEX process has been successfully tested on genuine spent fuel. However, in the latest EU Project ACSEPT, which started in 2008, another approach towards partitioning is being investigated. This is the so called GANEX (Group ActiNide EXtraction) process. In the GANEX process all the actinides in the dissolved spent fuel are extracted as a group and hence separated from the lanthanides as well as the rest of the fission and corrosion/activation products. A novel GANEX process has been developed at Chalmers university of Technology in Sweden. This new process utilizes the properties of already well known extractants by combining BTBP and TBP into one solvent. The system is able to extract U, Np, Pu and Am from strong nitric acid and simultaneously separate these elements from the lanthanides. This is done with sufficiently high distribution ratios and separation factors without the need for any redox control.
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| 45. |
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| 46. |
- Aneheim, Emma, 1982, et al.
(författare)
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Extraction experiments after radiolysis of a proposed GANEX solvent - the effect of time
- 2012
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Ingår i: Procedia Chemistry. - : Elsevier BV. - 1876-6196. ; 7, s. 123-129
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Konferensbidrag (refereegranskat)abstract
- In a solvent intended for use within group actinide extraction CyMe4-BTBP and TBP are combined together in cyclohexanone. After irradiating the solvent in acid contact a latency period before extraction reduced the extraction capability of plutonium. This reduction was larger when the solvent was kept in contact with the acid after irradiation. The decrease in plutonium extraction could be an effect of both a reduced extraction performance of CyMe4-BTBP caused by hydrolysis as well as a shift in oxidation state of the plutonium as it was shown that oxidizing Pu(IV) to Pu(VI) decreased the extraction by the solvent. (C) 2012 Elsevier B. V. .. Selection and/or peer-review under responsibility of the Chairman of the ATALANTE 2012 Program Committee
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| 47. |
- Aneheim, Emma, 1982, et al.
(författare)
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Fission product interactions with nitrogen donor ligands used for spent nuclear fuel treatment
- 2013
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Ingår i: Polyhedron. - : Elsevier BV. - 0277-5387. ; 50:1, s. 154-163
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Tidskriftsartikel (refereegranskat)abstract
- The so called BTBP (bis-triazine bi-pyridine)-type molecules have been developed for liquid-liquid extraction in the advanced reprocessing of used nuclear fuel. One solvent composition that has proven to be promising for such an application is the combination of CyMe4-BTBP and tri-butyl phosphate (TBP) in cyclohexanone. This solvent can extract the actinides successfully but unfortunately some fission products are also co-extracted. One of the most problematic fission products is palladium, but silver and cadmium are also extracted by the proposed solvent, which has been investigated here. In this study it was found that CyMe4-BTBP in cyclohexanone, when extracting palladium from nitric acid, forms complexes that are soluble both in the organic and aqueous phase. The predominant complex observed in both phases established with mass spectrometry and confirmed by NMR is a 1:1 complex, contrary to silver that forms 2:2 complexes and cadmium that forms 1:2 complexes. The nitrate dependency of the palladium extraction from nitric acid into a BTBP containing organic phase was found to be two. However, with higher ionic strengths, such as under process conditions, the palladium was found to be salted out into the organic phase.
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| 48. |
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| 49. |
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| 50. |
- Aneheim, Emma, 1982, et al.
(författare)
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Single Centrifugal Contactor Test of a Proposed Group Actinide Extraction Process for Partitioning and Transmutation Purposes
- 2015
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Ingår i: Separation Science and Technology. - : Informa UK Limited. - 1520-5754 .- 0149-6395. ; 50:10, s. 1554-1559
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Tidskriftsartikel (refereegranskat)abstract
- In this work a solvent comprising of tri-butyl phosphate and bis-triazinyl, bi-pyridine in cyclohexanone has been used in a single centrifugal contactor test to evaluate its GANEX process potential. It was found that the density of the aqueous phase had to be increased to facilitate phase separation in the centrifuge. The kinetics of the system was also found to be relatively slow in the equipment of choice, especially regarding the stripping. However, it was still possible to recover more than 87% of all actinides in one extraction step with minor fission product contaminations using a flowrate of 30 mL/h.
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