<p>The aim of this study has been to clarify how the radiumdistribution in soils affects the radon emanation. Thedistribution of radium, uranium and thorium has been determinedusing sequential extractions. In the study, soils from twodifferent locations were investigated.</p><p>In the first part the applicability of the sequentialextraction method for determining Ra distribution in differentsoil types was investigated, using a simple sequentialextraction method. Sampled soils were clay, sand and till fromthe vicinity of the Stockholm Esker. The main part of Rnemanating Ra was associated with Fe oxides in the soil. Themethods applied provided information about the radon risk ofthe soil, but, inorder to gain more information on theprocesses governing Ra distribution and radon emanation insoils, a more detailed sequential extraction procedure would bedesirable.</p><p>The second part consisted of a detailed study of theradionuclide distribution and the geochemistry in a podzolisedglacial till from Kloten in northern Västmanland. A moredetailed sequential extraction procedure was used, and thespecific surface area of samples was measured. Samples weretaken from E, B, and C horizons; radium and thorium wereenriched in the B horizon, whereas uranium had its maximumconcentration in the C horizon. Extractable radium primarilyoccurred in the exchangeable pool, possibly organicallycomplexed, whereas extractable uranium and thorium were mainlyFe oxide bound. Oxide-bound Ra was important only in the Bhorizon. The radon emanation was not correlated with the amountof exchangeable Ra, but instead with the oxide bound Ra.However, the amount of oxide-bound Ra was too small to accountfor all the emanated Rn, thus, exchangeable Ra was interpretedas the main source of emanated Rn. This exchangeable Ra wasmore emanative in the B horizon than in the C horizon. Theexplanation is the larger surface area of the B horizonsamples; the specific surface area appears to be the maingoverning parameter for Rn emanation in this soil. The surfacearea is largely created by the precipitation of amorphous Feoxides, thus, Fe oxides has a significant effect on Rnemanation.</p><p>Comparing the two studies, the Stockholm samples had thesame amounts of oxide-bound Fe and surface-bound Ra. Still theradon emanation was much smaller for these samples than in theKloten soil. The amount of organic matter in the B horizon ofthe Kloten soil is however, much larger than the organic mattercontent in the Stockholm samples. It is suggested that thelarge Rn emanation in the B horizon of Kloten is caused by thecombined effect of Fe oxides and organic matter.</p><p>The variability of²²⁶Ra distribution in soils was also investigated.The²²⁶Ra distribution was determined for samples from60-70 cm and 80-90 cm depth, from three adjacent soil profilesin a podzolic glacial till. Ra distributions, and estimationsof Rn risk based on the Ra distributions, of a single soilprofile, are likely to be representative for a similar area,provided that the samples are taken from a sufficientdepth.</p><p>KEYWORDS: distribution, emanation, extraction, glacial till,podzol, Ra, radium, radon, Rn, sequential soil, spodosol, Th,thorium, U, uranium, variability</p>

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This thesis has been prepared for DIAMO, Branch GEAM Dolní Rožínka. Literature research includes a description of the ionizing radiation, natural radionuclides, mining of uranium ore and mineral deposits; Běstvina and Licoměřice. The experimental part includes sampling, analysis and evaluation of the content of selected radionuclides in the two selected locations. The content of uranium and radium in sludge from mine water treatment plant is determined annually by an external laboratory, using of semiconductor gamma-spectrometric analysis (GSA). Determination of both radionuclides in waters in these areas is carried out in the Centre of testing laboratories (SZLAB) in Dolní Rožínka. Uranium and radium activity is below the detection limit. Sludges from Běstvina, according to the results of external laboratories, routinely show activity of both radionuclides. But activity in the waters from this locality is below the detection limit. The goal of this diploma thesis is to verify the radionuclide content in sludge from CDV Běstvina by another method. As a comparative method was chosen determination of uranium using the UV-VIS spectrophotometry with separation on silicagel. Location Licoměřice was chosen as a reference. Like a supplementary method for determining the concentration of uranium was chosen ICP-MS. For the determination of the radium was chosen radiochemical method scintillator ZnS (Ag).

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In the field of nuclear medicine, radioisotopes are used for applications such as diagnostic imag- ing, treatment, and equipment sterilization. The most commonly used radioisotope in medicine is technetium-99m (Tc-99m). It is used in 80% of all nuclear medicine procedures. Its parent isotope is molybdenum-99 (Mo-99). NRU, which is now closed, formerly produced 40% of the worlds demand for Mo-99. The production capacity of this reactor has been supplemented by a network of cyclotrons and a modified research reactor. This study aims to provide an alternative means of production for Mo-99, as well as other radioisotopes by modifying the center pin of a standard 37-element bundle of a CANDU reactor. The neutron transport code DRAGON, and the neutron diffusion code DONJON were used to model a CANDU-9 reactor. The lowest, median, and highest power channels were chosen as candi- dates for the modified bundles. It was found that the reactor parameters were altered by a negligible amount when any one channel was used to house the modified bundles. Significant quantities of the radioisotope lutetium-177 as well as the generating isotopes of the alpha-emitting radioisotopes lead- 212/bismuth-212, and radium-223 were produced. However, only minute amounts of molybdenum-99, and the generating isotope of bismuth-213 were produced. / Thesis / Master of Applied Science (MASc)

What could it mean to be a physicist specialized in radioactivity in the early 20th century Vienna? More specifically, what could it mean to be a woman experimenter in radioactivity during that time? This dissertation focuses on the lived experiences of the women experimenters of the <i>Institut für Radiumforschung</i> in Vienna between 1910 and 1938. As one of three leading European Institutes specializing in radioactivity, the Institute had a very strong staff. At a time when there were few women in physics, one third of the Institute's researchers were women. Furthermore, they were not just technicians but were independent researchers who published at about the same rate as their male colleagues. This study accounts for the exceptional constellation of factors that contributed to the unique position of women in Vienna as active experimenters. Three main threads structure this study. One is the role of the civic culture of Vienna and the spatial arrangements specific to the <i>Mediziner-Viertel</i> in establishing the context of the intellectual work of the physicists. A second concerns the ways the Institute's architecture helped to define the scientific activity in its laboratories and to establish the gendered identities of the physicists it housed. The third examines how the social conditions of the Institute influenced the deployment of instrumentation and experimental procedures especially during the Cambridge-Vienna controversy of the 1920s. These threads are unified by their relation to the changing political context during the three contrasting periods in which the story unfolds: a) from the end of the 19th century to the end of the First World War, when new movements, including feminism, Social Democracy, and Christian Socialism, shaped the Viennese political scene, b) the period of Red Vienna, 1919 to 1934, when Social Democrats had control of the City of Vienna, and c) the period from 1934 to the <i>Anschluss</i> in 1938, during which fascists and Nazis seized power in Austria. As I show, the careers of the Institute's women were shaped in good part by the shifting meanings, and the politics, that attached to being a "woman experimenter" in Vienna from 1910 to the beginning of the Second World War. / Ph. D.

La caractérisation des transferts hydrologiques entre le domaine continental souterrain et la zone côtière est essentielle afin de mieux contraindre les bilans hydrologiques et de matière dans ces zones. Ce travail porte sur l'étude du fonctionnement hydrologique de la zone côtière sud de la lagune de Venise, et plus précisément sur les interactions entre les eaux de surface et les eaux souterraines des aquifères superficiels côtiers, où la charge hydraulique et le niveau du sol sont en dessous du niveau marin. <br />Les éléments majeurs et les isotopes stables de l'eau sont utilisés pour caractériser les processus de mélange au sein de l'aquifère de surface (0-30m). Nos résultats mettent en évidence la restriction de la salinisation de l'aquifère à une étroite bande côtière (<1km), en bon accord avec les résultats des travaux de modélisation hydrodynamique. En amont, le système de canaux constitue une barrière efficace de l'intrusion saline, malgré la subsidence de la zone, et le système d'irrigation/drainage permet un rafraîchissement permanent.<br />Les apports d'eau souterraine dans la lagune sont quantifiés en utilisant les traceurs des isotopes du radium et du radon. Leurs activités mesurées dans la lagune sont en excès par rapport à la mer et nécessitent un apport d'eau souterraine enrichie en ces traceurs, ce qui est confirmé par une approche de modélisation géochimique. Un bilan de masse à l'état stationnaire permet de calculer un flux variant entre 8.1x10^5 et 1.5x10^7 m3.j-1, dépendant fortement de la composition du pôle d'eau souterraine choisi. Ce flux, principalement dû à la recirculation d'eau lagunaire au sein des sédiments, est 2 à 10 fois plus élevé que le flux de surface, et représente potentiellement une source significative d'éléments dans les eaux côtières.

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