| 1. |
- Azeem, Hafiz Abdul, et al.
(författare)
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Towards the isolation and estimation of elemental carbon in atmospheric aerosols using supercritical fluid extraction and thermo-optical analysis
- 2017
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 409:17, s. 4293-4300
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Tidskriftsartikel (refereegranskat)abstract
- Air-starved combustion of biomass and fossil fuels releases aerosols, including airborne carbonaceous particles, causing negative climatic and health effects. Radiocarbon analysis of the elemental carbon (EC) fraction can help apportion sources of its emission, which is greatly constrained by the challenges in isolation of EC from organic compounds in atmospheric aerosols. The isolation of EC using thermo-optical analysis is however biased by the presence of interfering compounds that undergo pyrolysis during the analysis. EC is considered insoluble in all acidic, basic, and organic solvents. Based on the property of insolubility, a sample preparation method using supercritical CO2 and methanol as co-solvent was developed to remove interfering organic compounds. The efficiency of the method was studied by varying the density of supercritical carbon dioxide by means of temperature and pressure and by varying the methanol content. Supercritical CO2 with 10% methanol by volume at a temperature of 60 °C, a pressure of 350 bar and 20 min static mode extraction were found to be the most suitable conditions for the removal of 59 ± 3% organic carbon, including compounds responsible for pyrolysis with 78 ± 16% EC recovery. The results indicate that the method has potential for the estimation and isolation of EC from OC for subsequent analysis methods and source apportionment studies.
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| 2. |
- Bernhardsson, Christian, et al.
(författare)
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Environmental radiation baseline around the Belarusian nuclear power plant – assessments in Belarus and Lithuania
- 2023
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Ingår i: Medical Physics in the Baltic States : Proceedings of the 16<sup>th</sup> International Conference on Medical Physics - Proceedings of the 16<sup>th</sup> International Conference on Medical Physics. - 1822-5721. ; , s. 121-125
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Konferensbidrag (refereegranskat)abstract
- Prior to the operation of the first Belarussian nuclear power plant (BelNPP), the baseline of the radiation environment was determined within a radius of about 30 km from BelNPP. This independent assessment was carried out during two expeditions in 2019. In 2022, a similar survey was carried out (during the initialoperation of BelNPP) on the Lithuanian side of the boarder. Here we present the overall project and some general results of the baseline assessments.
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| 3. |
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| 4. |
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| 5. |
- Bernhardsson, Christian, et al.
(författare)
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Radiological environmental monitoring at the ESS facility – Annual report 2020
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Results from the radiological environmental monitoring of the European Spallation Source (ESS) are presented for year 2020.Among the 63 environmental samples analysed for gamma emitting radionuclides, no elevated levels of anthropogenic radioactivity were observed. All samples (except two samples of lichen) had activity concentrations below the MDA for the natural radionuclides as well as 137Cs, and normal levels of 40K. In sewage sludge, detectable levels of 177Lu and 1311 were observed in samples that were measured within one week after sampling.Mobile gamma spectrometry surveys were carried out around ESS and MAX IV (when operating at high frequency during a test run). No deviating radiation levels were observed.The samples analysed for their 3H activity concentration (120 samples) were generally below the detection limit using the current procedure, instrumentation and analysis time (MDA typically 1.6 Bq L-1). The results show no evidence of any local contamination of 3H in Lund during 2020.The 14C data in the 26 samples of grass, fruits, berries, crops, milk, honey and meat of in the Lund area and in southern Sweden is consistent with the declining 14C specific activity in atmospheric CO2. Seasonal variations were observed in the 14C data. No evidence of anthropogenic 14C contamination in the Lund area was noted during 2020.The report presents the first base-line measurements of 129I (10 samples) in the ESS environmental monitoring programme. The 129I activity concentrations ranged between (3.18 ± 0.20)∙1011 atoms/kg d.w. for grass and (1.31 ± 0.03)∙1013 atoms/kg d.w. for moss. These values are in the expected range.
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| 6. |
- Bernhardsson, Christian, et al.
(författare)
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ZERO POINT ASSESSMENT OF THE RADIATION ENVIRONMENT – EXAMPLES OF A PROGRAM APPLIED IN SWEDEN (ESS) AND IN BELARUS (BELNPP)
- 2019
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Ingår i: MEDICAL PHYSICS IN THE BALTIC STATES : Proceedings of the 14th International Conference on Medical Physics - Proceedings of the 14th International Conference on Medical Physics. ; , s. 85-88
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Konferensbidrag (refereegranskat)abstract
- Before commissioning of a nuclear facility it is important to determine the baseline of the radiation environment. Such baseline or Zero Point assessments can only,and uniquely, be made before start of operation of the facility and will serve several purposes when the facility is in operation. Here we report on the planning and implementation of such a Zero Point program for achieving high reproducibility and effectiveness of the assessments around two nuclear installations.
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| 7. |
- Edsfeldt, Andreas, et al.
(författare)
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Human Atherosclerotic Plaque Progression Is Dependent on Apoptosis According to Bomb-Pulse 14C Dating
- 2021
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Ingår i: JACC: Basic to Translational Science. - : Elsevier BV. - 2452-302X. ; 6:9-10, s. 734-745
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Tidskriftsartikel (refereegranskat)abstract
- Individuals with rapidly progressing atherosclerotic plaques are at higher risk of experiencing acute complications. Currently, we lack knowledge regarding factors in human plaque that cause rapid progression. Using the 14C bomb-pulse dating method, we assessed the physical age of atherosclerotic plaques and which biological processes were associated with rapidly progressing plaques. Interestingly, increased apoptosis was the main component associated with a young physical plaque age, reflecting rapid plaque progression. Our findings in combination with recent advances in imaging techniques could guide future diagnostic imaging strategies to identify rapidly progressing plaques or therapeutic targets, halting plaque progression.
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| 8. |
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| 9. |
- Eriksson Stenström, Kristina, et al.
(författare)
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Assessment of sediment sampling techniques for ESS environmental monitoring programme
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Radionuclides released and discharged into the environment from nuclear and other radiation-related facilities, such as the European Spallation Source (ESS), may accumulate in aquatic bottom sediments. Sediments should therefore, as recommended by the IAEA, be monitored regularly. This report describes the setting up of a methodology for zero-point assessments of the radiation levels in sediments of relevance for possible future releases from the ESS.Two types of sediment sampling devices have been tested: a grab sampler of the Lamotte type, and a stationary bottom trap consisting of a 5-L bucket placed on the bottom of a pond. The Lamotte grab sampler worked well in the absence of obstacles such as vegetation and stones. Sampling from boat may be advantageous in finding suitable sampling spots for the grab sampler. The stationary bottom trap, tested for more than two years at one of the ponds at the ESS facility, proved functional. To be certain to obtain sufficient sediment during collection period of one year, we recommend using three 5-L buckets per pond. The bottom trap is most likely not suitable for sampling in rivers with flowing water.For the sample preparation, sieving the sediment in a laboratory was found to be more efficient and more convenient compared to sieving at the sampling site. Freeze-drying was found superior, in terms of efficiency and dried sample texture, to drying the sediment in open air. Measurements of total carbon, total nitrogen, and the carbon to nitrogen ratio proved to have the potential to provide relevant information about the sources of the sediment. The results of gamma-ray spectrometry confirmed sediments as a useful indicator of radionuclides, with activity concentrations above the MDA levels for all reported radionuclides and samples, except for one site. Gamma-ray spectrometry measurements on the samples can provide information on local elevated levels of anthropogenic radionuclides and add information to the sources of the sediment itself.
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| 10. |
- Eriksson Stenström, Kristina, et al.
(författare)
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Environmental levels of radiocarbon in Lund, Sweden, prior to the start of the European Spallation Source
- 2022
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Ingår i: Radiocarbon. - 0033-8222. ; 64:1, s. 51-56
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Tidskriftsartikel (refereegranskat)abstract
- The European Spallation Source (ESS) is a neutron-based research facility under construction in Lund in southern Sweden. The spallation reactions will generate not only the desired neutrons, but also many radioactive byproducts, including 14C. As part of the licensing process, and as recommended by the IAEA, various preoperational studies are being carried out, including mapping the “zero-point” radiation environment around the site. As the city of Lund hosts several facilities using 14C-labeled substances, and since temporary and local 14C contamination have been observed in the past, 14C mapping is an important part of these baseline assessments. We here present a summary of 14C levels in various terrestrial environmental samples in Lund and in southern Sweden during the years 2012 to 2020. These environmental F14C do not display significantly elevated levels compared to sites located remote from Lund. We also describe a local 14C contamination event that was detected at the Lund Radiocarbon Dating Laboratory in 2009. Horse-chestnut leaves collected close to the laboratory exhibited F14C values of up to ∼25% above the clean air background. Elevated values of F14C were also found in a short tree-ring series, especially in 2007. The source of this contamination was identified and successfully removed.
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| 11. |
- Eriksson Stenström, Kristina, et al.
(författare)
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Identifying radiologically important ESS-specific radionuclides and relevant detection methods
- 2020
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Bok (refereegranskat)abstract
- The European Spallation Source (ESS) is under construction in the outskirts of Lund in southern Sweden. When ESS has entered the operational phase in a few years, an intense beam of high-energy protons will not only produce the desired spallation neutrons from a large target of tungsten, but a substantial number of different radioactive by-products will also be generated. A small part of these will be released to the environment during normal operation. During an accident scenario, a wide range of gases and aerosols may be released from the tungsten target. The palette of radionuclides generated in the ESS target will differ from that of e.g. medical cyclotrons or nuclear power plants, thus presenting new challenges e.g. in the required environmental monitoring to ensure that dose limits to the public are not exceeded. This project (SSM2018-1636), financed by the Swedish Radiation Safety Authority (SSM), aimed to strengthen competence at Lund University for measurement and analysis of ESS-specific radionuclides. First, an extensive literature review, including modelling as well as experimental analyses, of ESS-relevant radionuclides was performed. We found that radionuclide production in particle accelerators is well-known, while experience with tungsten targets is very limited. As a second part of the project, an independent simplified model of the ESS target sector for the calculations of radionuclide production in the ESS tungsten target was developed using the FLUKA code. We conclude that we have a fairly good agreement with results of other authors, except for 148Gd, and that the calculated radionuclide composition is sensitive to the nuclear interaction models used.In the third part of the project, known environmental measurement technologies for various ESS-relevant radionuclides were reviewed, focussing on pure difficult-to-measure alpha- and beta-emitters. Liquid scintillation counting (LSC) is a suitable technique e.g. for the important beta emitters 3H, 14C, 35S, 31P and 33P. Several ESS radionuclides of relevance for dose estimates have never been investigated by environmental analytical techniques, due to their absence in the normal environment. Alpha spectrometry seems promising for the analysis of alpha-emitting lanthanides, in particular for 148Gd. Among the many types of mass spectrometry techniques, ICP-MS (inductively coupled plasma mass spectrometry) and AMS (accelerator mass spectrometry) seem to be the most suitable for the analysis of long-lived ESS radionuclides in environmental samples (e.g. 243Am and possibly lanthanides for ICP-MS and 10Be, 14C, 32Si, 36Cl, 60Fe and 129I for AMS).Three experimental parts were performed during the project, related to initiation of radioactivity measurements of aerosols at Lund University, mapping of environmental tritium in the Lund area, and establishment of a method to measure tritium in urine followed by a study of tritium in persons presently living or working in Lund. Aerosols were collected at a rural background station (Hyltemossa near Perstorp, northern Skåne) using a high-volume aerosol sampler with automatic filter change (DHA-80, Digitel). Gamma spectrometry measurements of 7Be agreed rather well with results from a nearby air monitoring station (SSM/FOI). Tritium (radioactive hydrogen) is expected to dominate the source term from the ESS target station to the environment. We have performed several investigations to monitor the current situation of tritium in Lund using LSC: the matrices investigated included air humidity, precipitation, pond water, indoor air at one accelerator facility and urine from the general public as well as from persons who may be occupationally exposed to tritium. Environmental tritium was generally very low (<3.4 Bq L-1), with somewhat higher concentration in the springtime than during the rest of the year. Tritium in the vast majority of the 55 urine samples was also very low: only a few exposed workers were found to have up to 11 Bq L-1 in their urine, which still is very low compared to e.g. reactor workers. Suggestions for further actions and work related to measurement and analysis of ESS relevant radionuclides are presented.
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| 12. |
- Eriksson Stenström, Kristina, et al.
(författare)
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PREOPERATIONAL ASSESSMENT OF 14C IN THE VINICINITY OF THE BELARUSIAN NUCLEAR POWER PLANT
- 2021
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Ingår i: Medical Physics in the Baltic States : Proceedings of the 15th International Conference - Proceedings of the 15th International Conference. - 1822-5721. ; , s. 133-137
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Konferensbidrag (refereegranskat)abstract
- As part of an independent assessment of the preoperational radiation environment around the Ostrovets nuclear power plant in Belarus, grass and foodstuffs were collected in 2019 for 14C analysis. The preoperational 14C specific activities in the Ostrovets region were shown to be similar to that of European data from other uncontaminated sites.
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| 13. |
- Eriksson Stenström, Kristina, et al.
(författare)
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Project SSM2019-5225: “Marine 14C levels around the Swedish coast” – Additional gamma spectrometric measurements and ICP-MS analysis of brown algae (Fucus spp.)
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The results of the project SSM2019-5225, “Marine 14C levels around the Swedish coast”, financed by the Swedish Radiation Safety Authority (SSM), are presented in the paper “Spatial and temporal variations of 14C in Fucus spp. in Swedish coastal waters” published in the Journal of Environmental Radioactivity. The project SSM2019-5225 focussed on spatial variations in 14C in Fucus spp. samples collected in 2020 along the entire Swedish west coast, in coastal waters in the very south of Sweden, and for the east coast up into the Gulf of Bothnia. In this report we present results from additional measurements of the Fucus spp. samples, using gamma-ray spectrometry (of 7Be, 40K, 60Co, 137Cs and 131I) and inductively coupled plasma mass spectrometry (ICP-MS) (of Co, Ni, Cd, Gd, Hg and Pb). The gamma spectrometry showed in addition to the expected content of natural 40K also 137Cs and 7Be, and at some places also 60Co and 131I. The ICP-MS analysis revealed a correlation between F14C and Gd, and the highest values of F14C and Gd were found close to Ringhals nuclear power plant. This strengthens the hypothesis that that a significant part of the observed peak in F14C on the west coast originates from Ringhals nuclear power plant.
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| 14. |
- Eriksson Stenström, Kristina, et al.
(författare)
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Radiological environmental monitoring at the ESS facility – Annual report 2021
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Results from the radiological environmental monitoring of the European Spallation Source (ESS) are presented for 2021. Previous zero-point assessments (2017-2020) have mainly focussed on terrestrial samples. New sample types for 2021 include a sediment sample from a pond at the ESS and brown seaweed (Fucus) from Lomma bay and from the east coast of Scania (Skillinge). For gamma-emitting radionuclides, increased levels of anthropogenic radioactivity (177Lu and 131I) originating from hospital use, were only observed in sewage sludge samples. For tritium, the majority of the samples had activity concentrations that were below the minimum detectable activity (MDA) of 1.62 Bq l-1. Expected environmental levels, without any evidence of local contamination, were also seen in the 14C data.
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| 15. |
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| 16. |
- Frost, Robert, et al.
(författare)
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Development of a Pelletron-based compact neutron source : At the Nuclear Applications Laboratory, Lund University
- 2023
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Ingår i: Journal of Neutron Research. - 1023-8166. ; 24:3-4, s. 281-287
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Tidskriftsartikel (refereegranskat)abstract
- The Applied Nuclear Physics Group at Lund University is constructing a prototype CANS (Compact Accelerator-driven Neutron Source). The CANS is based around a 3 MV, single-ended, Pelletron accelerator, which is used to impinge a 2.8 MeV deuterium beam into a beryllium target. The anticipated neutron production will be on the order of 1010 n/s in 4π sr. A further upgrade to the ion source of the Pelletron is expected to increase neutron production to 1011 n/s. Neutron energies will be up to 9 MeV with peak emission at ∼5 MeV. Shielding and moderation will be provided by a large water tank surrounding the target, with three exit ports to allow neutrons of different energies to be directed to experiments. The design is supported by simulation results which predict fast-neutron fluxes of 9×104 to 5×106 n/cm2/s, and thermal-neutron fluxes of 1×104 to 5×104 n/cm2/s to be readily obtainable with a 10 µA deuteron beam.
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| 17. |
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| 18. |
- Martinsson, Johan, et al.
(författare)
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Exploring sources of biogenic secondary organic aerosol compounds using chemical analysis and the FLEXPART model
- 2017
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 17:18, s. 11025-11040
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Tidskriftsartikel (refereegranskat)abstract
- Molecular tracers in secondary organic aerosols (SOAs) can provide information on origin of SOA, as well as regional scale processes involved in their formation. In this study 9 carboxylic acids, 11 organosulfates (OSs) and 2 nitrooxy organosulfates (NOSs) were determined in daily aerosol particle filter samples from Vavihill measurement station in southern Sweden during June and July 2012. Several of the observed compounds are photo-oxidation products from biogenic volatile organic compounds (BVOCs). Highest average mass concentrations were observed for carboxylic acids derived from fatty acids and monoterpenes (12. 3 ± 15. 6 and 13. 8 ± 11. 6 ng mg-3, respectively). The FLEXPART model was used to link nine specific surface types to single measured compounds. It was found that the surface category sea and ocean was dominating the air mass exposure (56 %) but contributed to low mass concentration of observed chemical compounds. A principal component (PC) analysis identified four components, where the one with highest explanatory power (49 %) displayed clear impact of coniferous forest on measured mass concentration of a majority of the compounds. The three remaining PCs were more difficult to interpret, although azelaic, suberic, and pimelic acid were closely related to each other but not to any clear surface category. Hence, future studies should aim to deduce the biogenic sources and surface category of these compounds. This study bridges micro-level chemical speciation to air mass surface exposure at the macro level.
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| 19. |
- Mattsson, Sören, et al.
(författare)
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Gadolinium in coastal waters -Time trends and possible sources
- 2023
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Ingår i: Medical Physics in the Baltic States 2023 : Proceedings of the 16th International Conference on Medical Physics - Proceedings of the 16th International Conference on Medical Physics. ; , s. 112-114
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Konferensbidrag (refereegranskat)abstract
- Samples of Fucus serratus and Fucusvesiculosus taken in Swedish coastal waters have beenanalysed for Gd by ICP-MS. The results for one site withfrequent sampling show significantly increasing levelsduring the last 30 years, most likely a result of theincreasing use of Gd-containing contrast agents for MR-imaging at hospitals and other health care institutions.Samples taken at the west-, south- and east-coast in 2020show considerable variation in Gd-concentration fromsite to site with highest level in northern Kattegat.
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| 20. |
- Mattsson, Sören, et al.
(författare)
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Long-time variations of radionuclides and metals in the marine environment of the Swedish west-coast studied using brown algae : (Fucus serratus and Fucus vesiculosus)
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The support from SSM has made it possible to continue collecting brown algaefrom the place on the Swedish west coast where regular collections began asearly as 1967. The support has also enabled more extensive analyses ofpreviously collected material than was possible before. This applies to bothsupplementary analyses of previously reported radionuclides and analysis ofnew ones. The project has also enabled a start of more comprehensive analysesof the overall results. This has provided better information about long-termprocesses and seasonal variations for different radionuclides in both toothedwrack (Fucus serratus) and bladderwrack (Fucus vesiculosus). What is new isthat the sample material has now also been used to analyse metals, both thosewith known toxic effects such as lead, cadmium and mercury, as well as thosethat are of interest in assessing transport routes for radionuclides generated innew radiation sources, such as gadolinium isotopes from the EuropeanSpallation Source (ESS).Regarding the long-term development of various radionuclides in the marineenvironment on the Swedish west coast, the studies show rapidly increasinglevels of iodine-129, decreasing levels of cesium-137, technetium-99 andplutonium-239+240. The carbon-14 analyses suggest a continued inflow of thisradionuclide from the North Sea. The study also shows that the brown algaecould be important for the monitoring of emissions of naturally occurringradioactive materials (NORM) from the offshore oil and gas industry bysystematically studying long-term and seasonal variations of the content ofradium-228 and in the future also radium- 226 and lead-210. Interesting andhitherto unexplained variations in the beryllium-7 content in Fucus have beenmade. The tritium content in Fucus and in seawater has been analysed in alimited number of samples from 2020. No levels beyond the expected normalambient level for tritium have been found.During the 10-year period 2011-2020, there was a doubling of the levels of leadand nickel and a 50% increase in the levels of cadmium and cobalt in Fucus. Formercury a 10-fold decrease is registered between 2011 and 2016 and then adoubling of the concentration between 2016 and 2020. The decreasing trend formercury probably indicates an effect of the gradual phasing out of mercury inSweden and other countries. However, some businesses and companies have anexemption for continued use. For gadolinium there is an increase with a factor ofaround 5 from 2011 to 2020, most likely explained by the increased use ofgadolinium-containing contrast agents in magnetic resonance imaging inhealthcare.
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| 21. |
- Pédehontaa-Hiaa, Guillaume, et al.
(författare)
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Evaluation of the region-specific risks of accidental radioactive releases from the European Spallation Source
- 2021
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Ingår i: Medical Physics in the Baltic States : Proceedings of the 15th International Conference on Medical Physics - Proceedings of the 15th International Conference on Medical Physics. - 1822-5721. ; , s. 142-146
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Konferensbidrag (refereegranskat)abstract
- The European Spallation Source (ESS) is a neutron research facility under construction in southern Sweden. The facility will produce a wide range ofradionuclides that could be released into the environment. Some radionuclides are of particular concern such as the rare earth gadolinium-148. In this article, the local environment was investigated in terms of food production and rare earth element concentration in soil. The collected data will later be used to model thetransfer of radioactive contaminations from the ESS.
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| 22. |
- Pédehontaa-Hiaa, Guillaume, et al.
(författare)
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How to detect radionuclides specific to the European Spallation Source in soil samples?
- 2023
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Ingår i: Medical Physics in the Baltic States (2023) : Proceedings of the 16th International Conference on Medical Physics - Proceedings of the 16th International Conference on Medical Physics. ; , s. 115-120
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Konferensbidrag (refereegranskat)abstract
- The European Spallation Source (ESS) is a neutron research facility under construction in southern Sweden. The facility will produce a wide range of radionuclides including 148Gd, 187W, 172Hf, 182Ta and 178nHf that could be released into the environment in an accident scenario. Detection limits for these contaminants in soil were estimated to be in the mg k-1 range for ICP-MS and <3 Bq per 200 ml soil for gamma-ray spectroscopy.
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| 23. |
- Pédehontaa-Hiaa, Guillaume, et al.
(författare)
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Investigation of the limits of detection for specific radionuclides in soil from the European Spallation Source (ESS) using radiometric and mass spectrometric methods
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This study provides information about the concentration of Tungsten (W), Hafnium (Hf) and Tantal (Ta) in the ESS soil and recommendations on the most appropriate sample preparation and measurement technique to assess contamination by these elements. The current levels of W, Hf and Ta measured in this study are in agreement with the estimated values from previous geological surveys. ICP MS showed low limits of detection for W, Hf and Ta and is thus an appropriate technique for environmental monitoring. However, the three metals are difficult to extract from soil and require the use of specific sample preparation methods (based on hydrofluoric acid for example). The transfer of stable W, Hf and Ta from soil to plant is poorly known and only a handful of publications can be found that are relevant to the plants grown around the ESS. The transfer of the radioisotopes of W, Hf and Ta in particular to animals (and man) is even less studied. However, the existing articles indicate a fast excretion of radio-W and radio-Ta while the excretion is slow for radio-Hf.The Minimum Detectable Activity (MDA) for gamma emitter released from the ESS facility will depend not only on the performances of the detection equipment but also on the composition of tungsten target at the time of the release. The determination of limits of detection of ESS related gamma emitters was performed using a strategy based on simulation of spectra. Semi-synthetic gamma spectra were obtained by combining real soil measurements with simulated data for mixtures of ESS radionuclides using the software Nucleonica. The simulation of 187W spectra was used as a proof of concept for the method. With this approach, it is possible to estimate limits of detection by gamma spectroscopy for a given target composition. The limits of detection of four relevant radionuclides were successfully determined for two different compositions of the ESS target and at three different activity concentrations in soil.
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| 24. |
- Pédehontaa-Hiaa, Guillaume, et al.
(författare)
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Region-specific radioecological evaluation of accidental releases of radionuclides from ESS
- 2021
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Bok (refereegranskat)abstract
- Gadolinium-148 is one of the radionuclides of most concern that will be produced in the tungsten target of the European Spallation Source (ESS), as a by-product of the spallation reaction used by the facility to produce neutrons. Since 148Gd a pure alpha emitter, it is both very radiotoxic and difficult to measure. With its half-life of 75 years, it will remain in the environment for a long time if released from the facility during normal operation or after an accident. There are still uncertainties regarding the amounts that actually will be produced by spallation in the tungsten targets of the facility. As Gd-148 does not occur naturally in the environment, there is no information available about its analysis in environmental samples but a few studies provide data from irradiated target material analysed by alpha spectroscopy or inductively coupled plasma mass spectrometry (ICP-MS). This report is a continuation of the SSM project as described in the SSM report 2020:08, entitled “Identifying radiologically important ESS-specific radionuclides and relevant detection methods” that focused on the ESS-related radionuclides that will be the most relevant to study and monitor in the environment as well as the analytical techniques to detect them. The present report focuses on the rare earth elements (REEs), including their radioactive isotopes, in particular Gd-148, and is intended to highlight the knowledge gaps that exist regarding their fate in the specific environment of the ESS area. In the first part of the report, the available literature on radioecological models was reviewed, with emphasis on ESS-related radionuclides. The existing modelling programmes were surveyed as well as the most relevant environmental parameters and experimental radioecological data required to build models specific to the ESS.In the second part of the report, the area in the vicinity of the ESS was surveyed to identify the important producers of foodstuff, what plant species are grown in the area and also the local husbandry and hunting practices, in order to identify critical pathways after a radioactive dispersion into the environment in connection with a potential accident at the ESS. In the third part of this report, after a thorough literature review and preliminary assays, we propose to investigate the use of ICP-MS for assessment of Gd-148 in the event of an accidental release, knowing that this analytical technique is already used for the measurement of stable Gd and REEs in the environment. The existing methods to extract REEs from environmental samples (soil, water, plants, and animal products) and to properly assess their concentration are described in the form of a literature review. The presented examples of methods were selected to fit the type of environment found around the ESS facility and the local agricultural and horticultural practices. A pilot study was also conducted to test extraction and measurement methods on the specific type of soil around ESS. These results are presented at the end of this report.
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| 25. |
- Raaf, Christopher L., et al.
(författare)
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In vivo measurement of pre-operational spallation source workers : Baseline body burden levels and detection limits of relevant gamma emitters using high-resolution gamma spectrometry
- 2019
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 0952-4746 .- 1361-6498. ; 40:1, s. 119-133
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Tidskriftsartikel (refereegranskat)abstract
- As a measure to prepare for long-term internal dose monitoring of workers at the European Spallation Source (ESS) in Lund, Sweden, operated by the European Research Infrastructure Consortium (ERIC), as well as to enhance emergency preparedness against accidental releases, a series of in vivo measurements were conducted using a high-resolution HPGe detector with a 123% relative efficiency (1.332 MeV). This study describes the whole-body counting set-up, calibration procedure, and subsequent validation measurements using conventional NaI(Tl)-scanning-bed geometry on a selection of workers from the ESS. Detection limits for the relevant gamma emitters 7Be, 172Hf, and 182Ta were determined to be 65 Bq, 130 Bq, and 22 Bq, respectively, using a 2400 s acquisition time. The baseline measurements suggest that care must be taken to ensure that the fluctuations in the presence of radon daughters 214Bi and 214Pb are minimised by, for example, ensuring a minimum air exchange between the measuring room and the ambient air, and by demanding that the measured subjects change clothes and shower before measurement. Furthermore, in a monitoring program for internal doses to spallation source workers, the presence of radionuclides originating from non-work-related sources (such as 226Ra from private water wells or 137Cs from intakes of Chernobyl contaminated foodstuffs), or radionuclides from previous work history (such as 60Co within the nuclear power industry), must be considered.
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