Das Projekt "Measurements of fission products in the experiments mol 7C/6 and mol 7C/7" wird vom Umweltbundesamt gefördert und von Forschungszentrum Karlsruhe GmbH Technik und Umwelt durchgeführt. Objective: During core melt-down accidents, significant fractions of the fission product inventory can be released from the molten fuel to the sodium, and subsequent to vessel failure; a further release of fission products from the evaporating sodium-pool to the atmosphere will occur. The physical processes which occur in the mol 7c experiments, melting of the fuel in presence of sodium, being comparable with a real accident, interesting and important information can be obtained with respect to the source term problem of core melt-down accidents. Measurement of the activity concentration of the different fission products in the sodium and relating it to the mass of disrupted and molten fuel could provide nuclide-specific transfer factors. The unique features offered by the mol 7c experiments (release of radio nuclides from genuine molten LMFBR fuel through sodium vapour and liquid) can be fully utilized with the addition of a fission products measuring device, without interfering with the main objective of the experiment. General information: the upper part of the sodium circuit of the mol 7c in-pile section extends above the reactor top cover. So, fission product activity measurements can be made in front of the expansion tank which forms the upper part of the mol 7c loop. Activity measurements are made with a ge-li detector incorporated in an under water measuring device. This device has been conceived and used for the scanning of LWR fuel elements in the reactor pool. Between the detector and the mol 7c loop a collimator tube is installed. In front of the detector the lead shield around the upper part of the mol 7c loop is provided with a window. A preliminary evaluation of the detection limits of the fission products under theses circumstances gives the following results: - isotopes considered in the evaluation: 18 - isotopes easy to be measured: 8 sr91, i131, i133, ru103, ru105, te132, i134, i135 - isotopes detectable: 6 zr95, y92, y 93, zr97, ba140, nd149 - isotopes not detectable or with interference: 4 y91, te127m, ce144, nd147. The fabrication of the measuring device is in progress and it is scheduled to be available when the mol 7c/6 experiment is being carried out.
Das Projekt "Exzellenzcluster 80 (EXC): Ozean der Zukunft" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum für Ozeanforschung Kiel (GEOMAR), Forschungsbereich 2: Marine Biogeochemie, Forschungseinheit Marine Geosysteme durchgeführt. The proposed research project focuses on risks arising from CO2 leakages for the marine environment associated with submarine CO2 storage. Carbon capture and storage (CCS) is considered as one important measure to reduce global anthropogenic CO2 emissions by the IPCC (IPCC, 2007) and various international studies (STERN, 2007). CO2 from industrial sources will be stored in geological formations located on land or below the seafloor. Future CO2 storage sites have to accommodate huge and continuous streams of CO2 (greater than 10 Mio t yr-1). The response of the sub-seafloor hydrological system to this major perturbation is largely unknown. A solid understanding of the leakage potential and environmental risks associated with submarine CO2 storage will only emerge while large-scale disposal sites are coming into operation. Thus, the legal framework and future monitoring activities have to be designed in the face of considerably uncertainty (STOLL and WALLMANN, 2008).
Das Projekt "Ermittlung von Transferfaktoren beim Uebergang von Cs 137, Sr 90 und Pb 210 aus dem Futter in das Fleisch von Schlachttieren" wird vom Umweltbundesamt gefördert und von Bundesanstalt für Fleischforschung, Institut für Chemie und Physik, Isotopenlaboratorium durchgeführt. A) Ermittlung des Transfers laengerlebiger Radionuklide aus der Umwelt in das Fleisch von Schlachttieren. B) Radiochemische Reinigung der vorwiegend aus Futtermitteln und Fleisch isolierten Radionuklide; Messung der Aktivitaet durch Low-Level Counting.
Das Projekt "Sub project: Influence of fluids from the ocean crust on growth and activity of deep-biosphere populations (IODP Leg 301)" wird vom Umweltbundesamt gefördert und von Carl von Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres durchgeführt. The sediment column of IODP Site 1301 of the eastern flank of the Juan de Fuca Ridge (water depth: 2650 m, sediment coverage: 265 m) is characterised by a diffusive flow of hydrothermal fluids from the underlying ocean crust, a steep temperature gradient of 0.23 degree C/m and two sulfate-methane transition zones. One goal of our project is to understand the role of fluids as a driving force for the marine deep biosphere by introducing electron acceptors to deeply buried sediments. This hypothesis was supported by cell quantification and activity measurements along the sediment column. Elevated cell numbers at the sediment-basement interface gave the first evidence for a microbial community stimulated by crustal fluids. Potential phosphatase activity was enhanced in phosphate-depleted layers towards the sediment-basement interface. Rates of sulfate reduction and anaerobic oxidation of methane were elevated within the lower sulfate-methane transition zone. Further investigations are focussed on isolation and characterisation of indigenous microorganisms. Molecular screening, used to determine the microbial composition of enrichment cultures from all sediment layers, revealed different phylotypes. However, as we are dealing with slowly growing prokaryotes, they need up to six months to form a colony. Therefore, the isolation and characterisation of new isolates and the preparation of publications will be finished until the end of the application period.
Das Projekt "Sub project: Geobiology of saline fluids from the deep biosphere obtained from the KTB pump test" wird vom Umweltbundesamt gefördert und von Universität Göttingen, Geowissenschaftliches Zentrum, Abteilung Geobiolgie durchgeführt. The major goal of the proposed project is the characterization of microbial biofilms formed in controlled environment biofilm model systems inoculated and maintained with fluids from the KTB pumping test originated from the deep continental biosphere. For this purpose, two controlled environment biofilm model systems are designated for the investigation of biofilm formation. System A is based on a modified Robbins Devices (MRD), that allows testing of different substrata, and coupons can be removed independently after various exposure times for examination of the biofilm or testing the effects of different media on biofilm growth in situ. Thin sections of different types of rock will be used as natural substrata for biofilm formation. For biofilm formation of putative thermophilic Archaea and Bacteria obtained from the deep subsurface fluids, a modified heatable chemostat (System B) is designated. The biofilms obtained from both systems will be investigated with regard to their overall phylogenetic structure, spatial arrangement and the cellular activity of the biofilm associated bacteria using fluorochromes for total cell count determination and fluorescent in situ hybridization (FISH). Analysis of the signature lipid biomarkers additonally provides quantitative measures of abundance, distribution and the nutritional status of the attached communities. Along with the microbiological investigations, biochemical analysis, especially for d13C, d15N, 2H isotopic compositions of specific organic compounds in the fluids (e.g. lipids) will be performed that could enable to elucidate microbiological driven processes within the deep biosphere.
Das Projekt "Teilprojekt 4" wird vom Umweltbundesamt gefördert und von bbe Moldaenke GmbH durchgeführt. bbe wird sich im Rahmen von SIGN II mit zwei Themenbereichen beschäftigen. Zum einen wird das neu entwickelte UV Floreszenz- Spektrometer im Wasserwerk HuaYan auf seine Fähigkeit zur Wasserwerkssteuerung getestet und optimiert. Zum anderen wird eine neue, auf Holographie basierende Technik erforscht, die eine Algenerkennung auf Spezies- Ebene ermöglicht und dabei aufgrund der angewendeten Algorithmen besonders schnell und präzise ist. Zusätzlich wird auch auf Zellebene eine automatische photosynthetische Aktivitätsmessung durchgeführt.
Das Projekt "Radiological aspects of recycling concrete debris from dismantling of nuclear installations" wird vom Umweltbundesamt gefördert und von Technischer Überwachungsverein Bayern Sachsen durchgeführt. Objective: Limiting values for the release of concrete with low-level residual radioactivity for the selective safe utilization (e.g., for noise barriers, earth fill, earth bank or substitute for foundation material) are presently not defined. The research programme will examine whether it is possible to define limiting values for radioactively contaminated concrete in the range of the limiting values for steel. The effect of radioactively contaminated concrete on the soil (leach out of radio nuclides) and on man (radiation exposure) will be determined. The results of these studies will have an effect on the decommissioning activities as far as buildings of the controlled area and the kind and quantity of the radioactively contaminated concrete are concerned. The advantage of the studies lies in an economic and safe recycling of large amounts of concrete with a low-level artificial residual radioactivity. Thereby, valuable ground storage space would be saved and natural gravel deposits would be preserved. The research work will provide data concerning cost saving by recycling concrete from controlled areas, radiation exposure of the decommissioning workers and of the general public. The research programme is performed in cooperation with CEA-IPSN, which has a research programme with a similar objective. General Information: WORK PROGRAMME: 1. Leach tests; 1.1. Design of the test facility and determination of concrete test specimen. (all); 1.2. Construction and operation of the test facility. (TUV-Bay.); 1.3. Literature survey on leaching out problems of radio nuclides in concrete. (TUV-Bay.); 1.4. Radiological measurements on concrete rubble before, during and after leach out tests. (TUV-Bay.); 2. Natural radioactivity in concrete; 2.1. Procurement of samples from recently produced and aged concrete. (RWE); 2.2. Measurement of alpha, beta and gamma radiation. (TUV-Bay.); 2.3. Literature survey concerning the natural radioactivity of concrete. 3. Development of methods for recycling concrete. 3.1. Examination of concrete recycling possibilities by a literature study. (RWE); 4. Calculation of radiation exposure and determination of the artificial residual radioactivity; 4.1. Determination of radiation exposure scenarios. (TUV-Bay.); 4.2. Calculation of radiation exposure for man due to natural and artificial radioactivity. (TUV-Bay.); 4.3. Derivation of criteria for the safe use of concrete with artificial radioactivity. (TUV-Bay.). Achievements: Limiting values for the release of concrete with low level residual radioactivity for selected safe utilisation (e.g. for noise barriers, earth fill, earth bank or substitute for foundation material) are presently not defined. The research programme will examine whether it is possible to define limiting values for radioactively contaminated concrete in the range of the limiting values for steel. The effect of radioactively contaminated concree on the soil (leach out of radio nuclides) and on man ...
Das Projekt "Erstellen von technischen Regeln fuer den Strahlenschutz" wird vom Umweltbundesamt gefördert und von Deutsches Institut für Normung, NA Kerntechnik durchgeführt. Technische Regeln zu den Themen: - Messverfahren zur Freigabe von kontaminierten Reststoffen. - Berechnung von Erkennungs- und Nachweisgrenzen. - Abschirmung von Detektoren fuer nuklidspezifische Aktivitaetsmessungen. - In-situ-Spektrometrie. - Passive Radonmessungen.
Das Projekt "Teilprojekt B" wird vom Umweltbundesamt gefördert und von Institut für Umwelt & Energie, Technik & Analytik e.V. durchgeführt. Die Zulassung von Chemikalien erfordert derzeit toxikologische Untersuchungen in Tiermodellen. Aus gesellschaftlichen und wissenschaftlichen Gründen besteht jedoch ein verstärktes Interesse an der Entwicklung und Validierung Humanzell-basierter Testsysteme als (teilweise) Ersatzmethoden zu den herkömmlichen in-vivo-Versuchen. Das Hauptziel dieses Projektes ist die Entwicklung einer Teststrategie zur Abschätzung potentieller neurotoxischer Effekte von Chemikalien mittels eines Systembiologie-basierten 3R-Verfahrens. Besonderes Augenmerk wird auf die Anwendbarkeit dieses Verfahrens hinsichtlich der Risikobewertung von Nanomaterialien gelegt. In diesem Rahmen werden eine Reihe innovativer in-vitro-Methoden eingesetzt. Neuronale Aktivitätsmessungen neuronaler Zellen aus embryonalen Stammzellen (ESZ) von Mensch und Maus werden mittels Multielektroden-Arrays als Maß für Hirnfunktion und Kognition erfasst. Zur Beantwortung dieser Fragestellungen sind Informationen hinsichtlich Exposition, Kinetik und Effekten der zu untersuchenden Materialien erforderlich. Als Referenzmaterialien werden zwei Insektizide (Organophosphate) und dazu zwei Nanopartikelproben genutzt, um einen (begrenzten) Vergleich zwischen und auch innerhalb von (chemischen) Stoffgruppen zu ermöglichen. IUTA wird in AP1 Projektmanagement und Öffentlichkeitsarbeit und AP4 Charakterisierung chemischer und physikalischer Eigenschaften der Nanopartikel beteiligt sein.
Das Projekt "Untersuchungen zum Schmelzen von radioaktivem Altmetall in einem kontrollierten Bereich" wird vom Umweltbundesamt gefördert und von Noell durchgeführt. Objective: the melting of radioactive metal waste has several advantages in comparison with other procedures, i.e.: reduction of the waste volume to be disposed of, safe enclosure of the radio nuclide in the metal matrix safe and exact determination of the radioactive inventory and, under certain conditions, harmless reuse of the metal. The aim of the investigations is the testing of the melting procedure on various types of waste metal, with surface contamination up to 500 bq/cm2 and specific activity up to 200 bq/g, under permanent operation conditions and in a controlled area. General information: b.1. Investigations on the distribution of radio nuclides in melt, slag, furnace liner and filter dust. B.2. Investigations on secondary waste, in function of the processed material, and on behaviour of the filter system. B.3. Investigations on committed doses and activity release as consequences of the melting work. B.4. Overall evaluation of the melting technique and comparison with alternative techniques (decontamination, compaction, direct disposal.). Achievements: the melting of 200 t of various highly contaminated steel wastes (200 bq/g and 500 bq/cm(2)) was not completed because the melting plant was prematurely decommissioned by the Kernforschungszentrum Karlsruhe, for economic reasons. In the work completed, however, it was found that cobalt-60 and other iron like nuclides remained, as expected, almost completely in the ingot, whereas caesium-137 and europium-152 were concentrated in the slag. In spite of the short operation time, it was shown that long term operation of the melting plant would be possible without significant radiation exposure to the workforce.
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