20.500.12556/RUL-187890 Prisotnost tritija in radioogljika v vodnih rastlinah na območju pretočne akumulacije Hidroelektrarne Brežice magistrsko delo Presence of tritium and radiocarbon in aquatic plants in the flow accumulation area of the Brežice hydroelectric power plant master thesis Uvod: Tritij in radioogljik, naravno prisotna in antropogeno sproščena radionuklida, se zaradi visoke mobilnosti kopičita v rastlinah in prehranskih verigah. Tritij se v organizmih pojavlja predvsem kot tritij v tkivni vodi in kot organsko vezan tritij, medtem ko se radioogljik med fotosintezo vgrajuje v organske spojine. Posebno vlogo pri zadrževanju in porazdelitvi teh radionuklidov imajo vodni sistemi s spremenjeno hidrodinamiko, kot je območje pretočne akumulacije Hidroelektrarne Brežice, ki se nahaja dolvodno od Nuklearne elektrarne Krško. Upočasnjen tok reke Save omogoča povečano zadrževanje snovi in njihovo akumulacijo v vodnih rastlinah, ki so zato pomembni bioindikatorji prostorskih in časovnih sprememb obremenitve okolja z radionuklidi. Namen: Namen magistrskega dela je analizirati prisotnost in porazdelitev tritija in radioogljika v vodnih rastlinah pretočne akumulacije Hidroelektrarne Brežice ter ovrednotiti vpliv sezonskih sprememb, lokacije vzorčenja, tipa rastline, padavinskega režima in obratovalnih značilnosti Nuklearne elektrarne Krško na njuno kopičenje. Metode dela: V raziskavi smo določili prisotnost radionuklidov tritija in radioogljika v vzorcih rastlin z uporabo tekočinske scintilacijske spektrometrije v akreditiranem laboratoriju Instituta »Jožef Stefan«. Vzorci so zajemali enoletne vodne rastline ter nekaj kopenskih rastlin kot primerjavo. Priprava vzorcev je vključevala pripravo vzorcev oz. merjencev, meritve ter obdelavo in interpretacijo rezultatov s pomočjo obdelave sekundarnih podatkov. Rezultati: Analiza tritija v tkivni vodi in organsko vezanega tritija je pokazala, da sta obe frakciji prisotni v vseh analiziranih vzorcih rastlin, pri čemer so bile vrednosti tritija v tkivni vodi višje in bolj razpršene kot vrednosti organsko vezanega tritija. Pri radioogljiku ni bilo zaznati bistvenih razlik med izmerjenimi vrednostmi. Razprava in zaključek: Raziskava je pokazala, da vodne rastline na območju pretočne akumulacije Hidroelektrarne Brežice ne izkazujejo povišanih aktivnosti tritija in radioogljika. Tritij v tkivni vodi se izkaže kot občutljiv pokazatelj kratkoročnih sprememb, medtem ko organsko vezan tritij in radioogljik odražata bolj stabilno, dolgoročno prisotnost radionuklidov v ekosistemu. Variabilnost aktivnosti je odvisna od kombinacije okoljskih dejavnikov, kot so izpusti Nuklearne elektrarne Krško, hidrološke razmere in biološka aktivnost rastlin, kar poudarja potrebo po sistematičnem in večletnem vzorčenju. Introduction: Tritium and radiocarbon, naturally occurring and anthropogenically released radionuclides, accumulate in plants and food chains due to their high mobility. In living organisms, tritium occurs primarily as tritium in tissue water and as organically bound tritium, whereas radiocarbon is incorporated into organic compounds through photosynthesis. Aquatic systems with altered hydrodynamics play a particularly important role in the retention and distribution of these radionuclides. One such system is the flow accumulation area of the Brežice Hydropower Plant, located downstream of the Krško Nuclear Power Plant, where the reduced flow velocity of the Sava River enables increased retention of substances and their accumulation in aquatic plants. These plants therefore represent important bioindicators of spatial and temporal changes in environmental radionuclide contamination. Purpose: The purpose of this master’s thesis is to analyse the presence and distribution of tritium and radiocarbon in aquatic plants within the flow accumulation area of the Brežice Hydropower Plant and to evaluate the influence of seasonal variations, sampling location, plant type, precipitation regime, and operational characteristics of the Krško Nuclear Power Plant on their accumulation. Methods: The presence of the radionuclides tritium and radiocarbon in plant samples was determined using liquid scintillation spectrometry in an accredited laboratory of the Jožef Stefan Institute. The samples included annual aquatic plants and several terrestrial plant species for comparison. Sample preparation comprised the preparation of samples and measurement media, the measurements themselves, and subsequent data processing and interpretation of results using the processing of secondary data. Results: The analysis of tritium in tissue water and organically bound tritium showed that both fractions were present in all analysed plant samples, with higher and more variable activities observed in tissue water tritium compared to organically bound tritium. No significant differences were detected among the measured radiocarbon values. Discussion and conclusion: The study demonstrated that aquatic plants in the flow accumulation area of the Brežice Hydropower Plant do not exhibit elevated activities of tritium and radiocarbon. Tritium in tissue water proved to be a sensitive indicator of short-term environmental changes, whereas organically bound tritium and radiocarbon reflect a more stable, long-term presence of radionuclides in the ecosystem. Variability in activity levels depends on a combination of environmental factors, including discharges from the Krško Nuclear Power Plant, hydrological conditions, and plant biological activity, highlighting the importance of systematic, long-term monitoring. magistrska dela sanitarno inženirstvo tritij radioogljik radioaktivnost vodne rastline pretočna akumulacija HE Brežice Nuklearna elektrarna Krško master's theses sanitary engineering tritium radiocarbon radioactivity aquatic plants flow accumulation area Brežice hydropower plant Krško nuclear power plant true false false [R. C. Pružek] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-09-16 07:46:04 2026-09-16 07:46:10 2026-09-17 04:29:49 0000-00-00 00:00:00 2026 0 Ljubljana 0 Ljubljana XI, 62 str., [3] str. pril. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 614 164800 291243779 63474.pdf 63474.pdf 1 F42E8D8A94E97A0FBACB76DE94C80893 c6732e23207075c0befe5410c878b769dc0807da44b1e8f45b90c7601ef28759 e2e92e91-b191-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=247717 Zdravstvena fakulteta 0 0 0