| 1. |
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| 2. |
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| 3. |
- Carlsson, C.A., et al.
(författare)
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An instrument for measuring ambient dose equivalent, H*(10)
- 1996
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Ingår i: Radiation Protection Dosimetry. - 0144-8420 .- 1742-3406. ; 67:1, s. 33-39
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Tidskriftsartikel (refereegranskat)abstract
- The design and calibration of a small and simple instrument for measuring the ambient dose equivalent, H*(10), in photon fields is described. Comprising a thermoluminescence LiF dosemeter inside a 20 mm diameter PMMA sphere, it is capable of measuring the ambient dose equivalent with a nearly isotropic response. In the interval 0.1-100 mSv and for the energy range 30 keV to 1.25 MeV the energy response is within -31% and +15% relative to that of 137Cs gamma radiation (662 keV). In practical use, it is therefore sufficient to calibrate the instrument in a 137Cs gamma field using the corresponding conversion coefficient H*(10)/Kair taken from tabulations. The possibility of using the instrument to monitor the ambient dose equivalent for energies above 1.25 MeV is discussed and indicates that the range of applicability can be extended to 4.4 MeV with an energy response within -10% relative to 662 keV.
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| 4. |
- Dahlén, Johan, et al.
(författare)
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Determination of nitrate and other water quality parameters in groundwater from UV/Vis spectra employing partial least squares regression
- 2000
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Ingår i: Chemosphere. - : Pergamon Press. - 0045-6535 .- 1879-1298. ; 40:1, s. 71-77
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Tidskriftsartikel (refereegranskat)abstract
- The use of UV/Vis spectroscopy in combination with partial least squares (PLS) regression for the simultaneous prediction of nitrate and non-purgeable organic carbon (NPOC) in groundwaters was evaluated. A model of high quality was obtained using first order derivative spectra in the range 200–300 nm. Inclusion of non-UV-absorbing constituents in the modeling procedure, i.e., chloride, sulfate, fluoride, total carbon (TC), inorganic carbon (IC), alkalinity, pH and conductivity was also evaluated. This model seemed to be useful for prediction of chloride, TC, IC, alkalinity and conductivity, while its ability to predict sulfate, fluoride and pH was poor. In conclusion, application of PLS regression, which requires neither filtration of samples nor addition of chemicals, is a promising alternative for fast interpretation of geochemical patterns of groundwater quality.
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| 5. |
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| 6. |
- Greis, Christina, 1975-, et al.
(författare)
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Determination of plutonium in environmental samples with quadrupole ICP-MS
- 2008
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - Berlin : Springer. - 0236-5731 .- 1588-2780. ; 275:1, s. 55-70
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Tidskriftsartikel (refereegranskat)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.
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| 7. |
- Gårdestig, Magnus, 1973-, et al.
(författare)
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Approved Personal Dosimetry for Medical Personnel using Direct Ion Storage Dosimeters
- 2009
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Ingår i: IFMBE Proceedings vol. 25/III. - Heidelberg : Springer. - 9783642038976 ; , s. 352-354
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Dosimeters based on the Direct Ion Storage technology is used as the first approved electronic personal dosimeter in Sweden at the County Councils in Östergötland and Kalmar. TL dosimeters are replaced by DIS-1 dosimeters for all category A personnel at six hospitals with totally 300 dosimeter holders. The advantages are longer issue periods and instant read outs, appreciated by both the service and the holders
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| 8. |
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| 9. |
- Hansson, Edvin, 1987-
(författare)
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Internal Dosimetry in Nuclear Fuel Fabrication : Occupational Exposure to Uranium Aerosols
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The production of nuclear fuel can be associated with occupational exposure to ionizing radiation from radioactive decay of uranium. Such exposure must be sufficiently low and radiation doses adequately determined. Radiation doses from internal exposure, i.e., following intake (usually inhalation), cannot be estimated using dosimeters, but must be calculated based on indirect measurements in combination with biokinetic models.Such biokinetic models have been developed and refined for decades. Good knowledge of the material characteristics is crucial. However, the physicochemical properties of chemical compounds can vary between different production facilities. Aerosol size distributions and dissolution characteristics in lung fluid are of particular importance. The latter is important since dissolved material is absorbed to blood, whereupon a large fraction reaches the urine after filtering by the kidneys. This enables urine sampling as a method to monitor occupational exposure.The aim of this thesis was to investigate the physicochemical properties of uranium aerosols and their implication on internal dose assessments at a nuclear fuel fabrication plant in Sweden. Uranium aerosols were sampled and size fractionated using personal cascade impactors carried by workers at the factory’s different main workshops. Aerosols were studied using scanning electron microscopy in Paper I. In Paper II the activity size distributions were determined and in Paper III dissolution rates in simulated lung fluid were investigated. Paper IV is an internal dose assessment based on records of urine sample analyses from about 10 years of routine occupational exposure monitoring of uranium pelletizing workers at the site.For a median worker, the urinary daily excretion rate of uranium increased due to chronic exposure for about 1000 days, after which the excretion rate stabilized. This suggests that inhaled material dissolves in the respiratory tract rapidly enough to prevent a net buildup in the lung after several years of exposure. This could be modelled using the default recommendations for uranium oxide materials provided by the International Commission on Radiological Protection. However, the best model fit to measurement data was obtained using a different set of parameters, that showed some discrepancies with results from Papers II-III. For individual cases, excretion rates could vary between sampling occasions to a greater extent than predicted using the default recommendations, which could indicate a more rapid body clearance than expected. Whether this is an effect of experimental methods or simplifications in the biokinetic models should be further investigated in future work.
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| 10. |
- Hansson, Edvin, 1987-, et al.
(författare)
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Particle Size-dependent Dissolution of Uranium Aerosols in Simulated Lung Fluid : A Case Study in a Nuclear Fuel Fabrication Plant
- 2022
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Ingår i: Health Physics. - : Lippincott, Williams & Wilkins. - 0017-9078 .- 1538-5159. ; 123:1, s. 11-27
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Tidskriftsartikel (refereegranskat)abstract
- Inhalation exposure to uranium aerosols can be a concern in nuclear fuel fabrication. The ICRP provides default absorption parameters for various uranium compounds but also recommends determination of material-specific absorption parameters to improve dose calculations for individuals exposed to airborne radioactivity. Aerosol particle size influences internal dosimetry calculations in two potentially significant ways: the efficiency of particle deposition in the various regions of the respiratory tract is dependent on aerodynamic particle size, and the dissolution rate of deposited materials can vary according to particle size, shape, and porosity because smaller particles tend to have higher surface-to-volume ratios than larger particles. However, the ICRP model assumes that deposited particles of a given material dissolve at the same rate regardless of size and that uptake to blood of dissolved material normally occurs instantaneously in all parts of the lung (except the anterior portion of the nasal region, where zero absorption is assumed). In the present work, the effect of particle size on dissolution in simulated lung fluid was studied for uranium aerosols collected at the plant, and its influence on internal dosimetry calculations was evaluated. Size fractionated uranium aerosols were sampled at a nuclear fuel fabrication plant using portable cascade impactors. Absorption parameters, describing dissolution of material according to the ICRP Human Respiratory Tract Model, were determined in vitro for different size fractions using simulated lung fluid. Samples were collected at 16 time-points over a 100-d period. Uranium content of samples was determined using inductively coupled plasma mass spectrometry and alpha spectrometry. In addition, supplementary experiments to study the effect of pH drift and uranium adsorption on filter holders were conducted as they could potentially influence the derived absorption parameters. The undissolved fraction over time was observed to vary with impaction stage cut-point at the four main workshops at the plant. A larger fraction of the particle activity tended to dissolve for small cut-points, but exceptions were noted. Absorption parameters (rapid fraction, rapid rate, and slow rate), derived from the undissolved fraction over time, were generally in fair agreement with the ICRP default recommendations for uranium compounds. Differences in absorption parameters were noted across the four main workshops at the plant (i.e., where the aerosol characteristics are expected to vary). The pelletizing workshop was associated with the most insoluble material and the conversion workshop with the most soluble material. The correlation between derived lung absorption parameters and aerodynamic particle size (impactor stage cut-point) was weak. For example, the mean absorption parameters derived from impaction stages with low (taken to be <5 mu m) and large (>= 5 mu m) cut-points did not differ significantly. Drift of pH and adsorption on filter holders appeared to be of secondary importance, but it was found that particle leakage can occur. Undissolved fractions and to some degree derived lung absorption parameters were observed to vary depending on the aerodynamic size fraction studied, suggesting that size fractionation (e.g., using cascade impactors) is appropriate prior to conducting in vitro dissolution rate experiments. The 0.01-0.02 mu m and 1-2 mu m size ranges are of particular interest as they correspond to alveolar deposition maxima in the Human Respiratory Tract Model (HRTM). In the present work, however, the dependency on aerodynamic size appeared to be of minor importance, but it cannot be ruled out that particle bounce obscured the results for late impaction stages. In addition, it was noted that the time over which simulated lung fluid samples are collected (100 d in our case) influences the curve-fitting procedure used to determine the lung absorption parameters, in particular the slow rate that increased if fewer samples were considered.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
- Lee, Sang-Han, et al.
(författare)
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Distribution of plutonium and americium in the marginal seas of the nothwest pacific ocean.
- 2003
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Ingår i: Deep-sea research. Part II, Topical studies in oceanography. - 0967-0645 .- 1879-0100. ; 50, s. 2727-2750
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Tidskriftsartikel (refereegranskat)abstract
- Plutonium isotopes and 241Am were studied in seawater and sediment from the East China Sea, the Yellow Sea, the East Sea/Sea of Japan, the Sea of Okhotsk, and the northwest Pacific Ocean, collected between 1993 and 1996 with the aim to contribute to better understanding the behaviour of plutonium and americium in the marine environment. 239,240Pu concentrations in surface water varied from 2.3 to 13 µBq l-1 in the East China Sea and from 3.5 to 9.4 µBq l-1 in the East Sea. The 239,240Pu vertical profiles in water showed a broad subsurface maximum between 500 and 1000 m with a range of 30-40 µBq l-1, and gradually decreased from 1000 m depth down to the seafloor. 241Am concentrations in surface water showed values from 1.1 to 2.2 µBq l -1 in the East Sea, from 1.0 to 3.1 µBq l-1 in the Sea of Okhotsk, and from 0.68 to 12.0 µBq l-1 in the northwest Pacific Ocean. The activity ratios of 241Am/239,240Pu in seawater showed values similar to the global fallout ratio, which suggests that the source of these radionuclides in the northwest Pacific Ocean is global fallout. However, the 241Am/239,240Pu activity ratios in sediment were found to be much higher (1.0-1.9) than the global fallout ratio (0.37), confirming that 241Am is scavenged from the water column more rapidly than 239,240Pu. The 239,240Pu inventories in the water column of the East Sea were from 0.98 to 93 Bq m-2 depending on water depth and sedimentation rates. The 241Am inventory in the water column east of Kamchatka was 6.3 ± 1.0 Bq m -2 and the sediment inventory in the Sea of Okhotsk was 16 ± 2 Bq m-2. 239,240Pu concentrations in sinking particles in the southwest Japan Basin were from 3.7 to 5.2 Bq kg-1 (dry weight) with fluxes of 0.19-4.50 mBq m-2 d-1 and at the Ulleung Basin from 2.4 to 3.7 Bq kg-1 (dry weight) with fluxes of 0.77-1.10 mBq m-2 d-1. The mean residence time of 239,240Pu in the water column of the East Sea derived from sediment trap data was 140 ± 20 years, 2-3 times less than in the Atlantic and Pacific oceans.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Pettersson, Håkan, 1956-, et al.
(författare)
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Summary of IAEA-MEL's investigation of Kara Sea radioactivity and radiological assessment
- 1997
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Ingår i: Marine Pollution Bulletin. - 0025-326X .- 1879-3363. ; 35:7-12, s. 235-241
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Tidskriftsartikel (refereegranskat)abstract
- IAEA-MEL participated in five expeditions to the Kara Sea with the aim of assessing the radiological consequences of dumped radioactive wastes in the Novaya Zemlya Bays and Trough. The programme included sampling, in-situ underwater investigations, laboratory analyses of water, sediment and biota samples, the development of a marine radioactivity database, modelling and radiological assessment, the organization of intercomparison exercises and the evaluation of distribution coefficients. Radiometric investigations have shown that no radiologically significant environmental contamination has occurred. Leakages which have led to locally increased levels of radionuclides in sediment have only been observed in Stepovoy and Abrosimov Bays. Computer modelling results suggest that only radiological effects on local and regional scales may be of importance. The global radiological impact of the disposals in the Arctic Seas will be negligible.
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| 19. |
- Pham, M. K., et al.
(författare)
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Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)
- 2006
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Ingår i: Proceedings of the 15th International Conference on Radionuclide Metrology and its Applications (Applied Radiation and Isotopes). - Amsterdam : Elsevier BV. - 0969-8043 .- 1872-9800. ; 64:10-11, s. 1253-1259
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Konferensbidrag (refereegranskat)abstract
- A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides (K-40, Cs-137, Th-232, U-234, U-235, U-238, Pu-238, Pu239+240 and Am-241) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides (Sr-90, Pb-210(Po-210), Ra-226, Pu-239, Pu-240 Pu-241). Less frequently reported radionuclides (Tc-99, I-129, Th-228, Th-230 and Np-217) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units.
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| 20. |
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| 21. |
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| 22. |
- Povinec, Pavel, et al.
(författare)
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Reference material for radionuclides in sediment. IAEA-384 (Fangataufa lagoon sediment).
- 2007
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - Dordrecht : Springer. - 0236-5731 .- 1588-2780. ; 273:2, s. 383-393
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Tidskriftsartikel (refereegranskat)abstract
- A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (40K, 60Co, 155Eu, 230Th, 238U, 238Pu, 239+240Pu and 241Am). Information values are given for 12 radionuclides (90Sr, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 232Th, 234U, 235U, 239Pu, 240Pu and 241Pu). Less reported radionuclides include 228Th, 236U, 239Np and 242Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units.
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| 23. |
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| 24. |
- Sandborg, Michael, 1961-, et al.
(författare)
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Evaluation of patient-absorbed doses during coronary angiography and intervention by femoral and radial artery access
- 2004
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 14:4, s. 653-658
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare the radiation dose to patients during coronary angiography (CA) and coronary intervention (percutaneous transluminal coronary angioplasty, PTCA) by the femoral or radial artery access routes. A plane-parallel ionisation chamber, mounted on an under-couch X-ray tube (Siemens Coroskop TOP with an optional dose reduction system), recorded the dose-area product (DAP) to the patient from 40 coronary angiographies and 42 coronary interventions by the femoral route. The corresponding numbers for radial access were 36 and 24, respectively. Using a human-shaped phantom, conversion factors between maximum entrance surface dose and DAP were derived for CA and CA plus PTCA, respectively. The dose to the staff was measured with TL dosimeters for 22 examinations. Fluoroscopy time and DAP were significantly (p=0.003) larger using the radial access route for coronary angiography (7.5 min, 51 Gy cm2) than the corresponding values obtained from femoral access route (4.6 min, 38 Gy cm2. For CA plus PTCA the fluoroscopy time and DAP were larger for radial access (18.4 min, 75 Gy cm2) than for femoral access (12.5 min, 47 Gy cm2, p=0.013). In our experience, radial access did significantly prolong the fluoroscopy time and increase the patient doses.
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| 25. |
- Söderberg, Jonas, 1969-, et al.
(författare)
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Katastrofer orsakade av joniserande strålning
- 2002. - 2
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Ingår i: Katastrofmedicin. - Linköping : Linköpings universitet. - 9147048565 - 9789147048564 ; , s. 303-318
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Denna bok beskriver hur man ska hantera den svåra uppgiften att bedriva sjukvård på effektivast möjliga sätt i alla de olika typer av situationer där det akuta vårdbehovet överstiger vad som kan klaras med tillgängliga resurser. Den täcker hela omhändertagandekedjan från skadeområdet till definitiv behandling på sjukhus. Denna nya upplaga av Katastrofmedicin är en helt ny bok, utökad till innehållet och uppdaterad mot bakgrund av den omfattande utveckling som präglat detta ämnesområde sedan föregående upplaga.Katastrofmedicin kan användas som både läromedel vid utbildning på alla nivåer och som en lättillgänglig handbok och vänder sig till såväl personal i prehospital vård som till läkare och sjuksköterskor på sjukhusens akutmottagningar och inom berörda specialiteter.
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| 26. |
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| 27. |
- Vesterbacka, P, et al.
(författare)
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Intercomparison of Rn-222 determination from groundwater
- 2010
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Ingår i: Applied Radiation and Isotopes. - : Elsevier. - 0969-8043 .- 1872-9800. ; 68:1, s. 214-218
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Tidskriftsartikel (refereegranskat)abstract
- An intercomparison exercise on Rn-222 determination in groundwater was organized between eight Nordic laboratories. The individual laboratory results were in most cases within 20% of the median value and within reported uncertainties. Considering the particular difficulties in preparing, transporting and analyzing Rn-222, being a gaseous radionuclide, the results indicate a high analytical capability among the Nordic laboratories. In order to maintain a high analytical quality, similar intercomparisons will also be needed in the future.
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