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Uranium in historical ceramic glazes: Determination by alpha radiation detection and comparison with other methods
Vopat, Michal ; Goliáš, Viktor (advisor) ; Jelínek, Emil (referee)
In the Czech Republic yellow and ivory glazes with uranium in the Ditmar-Urbach and Terra Teplice companies were manufactured in the pre-war and inter-war period. The production of these glazes took place at the latest since the 1900, the material springs have existed since 1912. Their production ended in 1945. The most suitable method of non-destructive determination of uranium was the measurement of surface alpha activity on planar surfaces by a probe with a ZnS (Ag) scintillator constructed special for this bachelor thesis. Altogether 85 samples, evidence of this production, were measured. To determine the conversion of detected alpha activity to uranium content, an indirect calibration method was chosen to measure uranium content in three types of glazes by WDS analysis. In the studied set, uranium contents ranged from 0.2-2.2 % with the highest frequency ranging from 0.5-0.6 % U. 16 samples of yellow and ivory glazes were without added uranium with contents up to 322 ppm eU. Comparison of uranium contents determined by surface alpha activity measurement with area beta activity confirmed that the glazing does not form a saturated layer for beta radiation. Three types of glazes analyzed by WDS were also measured by XRF. By comparing uranium contents determined by both methods, it was found that...
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Underground waters and springs at Jeseník Spa: New hydrogeochemical data
Kohn, Tomáš ; Goliáš, Viktor (advisor) ; Vylita, Tomáš (referee)
This thesis deals with the areal survey of water resources in the area of Priessnitz baths, to search for natural medicinal sources and advanced data collection for evaluation radiohydrogeochemical situation of the area. The area of interest is situated in the Hrubý Jeseník mountains. Hydrogeologically it is a hard rock, which consists mainly of metamorphic rocks of the Bohemian Massif, the Moravian-Silesian region, presented as the methamorfic envelope of the desen group of Silenics. Altogether, 83 objects were recorded and many of them were visited repeatedly. Physical parameters (temperature, pH, Eh, conductivity), activity 222Rn and flow rate were measured. In addition, the chemical composition and tritium contents were determined on selected sources. Conductometry, thermometry, and probes for peloids were conducted. There was no source of water (or peloid) that would reach the criteria of a natural healing source (according to the Czech spa law). However, the overall hydrogeological and hydrochemical situation is quite complicated. Both the genesis of water and its chemical composition is highly heterogeneous and influenced by the heterogenical geological structure. Generally, we have distinguished three types of water according to the chemical composition. We also divided the water sources...
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The Long-term Natural Corrosion of Uranium Coloured Glasses
Procházka, Radek ; Goliáš, Viktor (advisor) ; Zeman, Josef (referee) ; Helebrant, Aleš (referee)
klíčová slova: koroze skla, zvětrávání skla, přírodní alterace skla, přírodní analog, uran, experimentální loužení Historická skla barvená uranem byla vyráběna v řadě českých skláren přibližně mezi lety 1830 a 1945. Obsah uranu v těchto sklech se pohybuje v řádu desetin procenta. Materiál představuje vhodný analog tzv. nukleárních skel sloužících k imobilizaci radioaktivního odpadu. Vzhledem ke složitosti procesů předpokládaných v podzemním úložišti v době kdy se odpadní skla dostanou do kontaktu s vodou má materiál velkou vypovídací hodnotu pro posouzení dlouhodobé stability skla v přírodních podmínkách se zaměřením na chování uranu. V předložené práci jsou studovány změny historických uranem barvených skel vystavených až 150 let působení přírodních roztoků v exogenních podmínkách. Během této doby došlo na povrchu vzorků ke korozi. U draselných skel bylo při povrchu zjištěno preferenční vyloužení alkálií a vznik hydratované difúzní zóny o mocnosti až 0,6 mm. V této korodované části bylo pozorováno srážení novotvořeného kalcitu (CaCO3) patrně v důsledku zvýšeného pH. Oproti původnímu sklu byla ve vyloužené zóně potvrzena stabilní, v některých případech zvýšená koncentrace uranu. Ačkoli došlo k vyloužení až 17,5 % K2O a nahrazení prakticky veškerého draslíku ionty H3O+ z roztoku, uran zůstal ve...
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