Techn. Hochsch., Diss., 2004--Aachen.

The Institute of Safety Research (ISR) is one of the six Research Institutes of Forschungszentrum Dresden-Rossendorf e.V. (FZD), which is a member institution of the Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz (Leibnizgemeinschaft). Together with the Institutes of Radiochemistry and Radiation Physics, ISR implements the research programme „Nuclear Safety Research“, which is one of the three scientific programmes of FZD. The programme includes two main topics, i. e. “Safety Research for Radioactive Waste Disposal” and “Safety Research for Nuclear Reactors”.

Modern Societies have to consider diverse tasks strongly related to geochemistry sciences. Examples intensively discussed in the public are restoration measures for contaminated industrial fallow grounds, the safe storage of chemical-toxic and radioactive waste, carbon dioxide sequestration to reduce green-house gas emissions, the construction and operation of deep geothermal power plants, the geochemical exploration of natural resources or water and waste water treatments, including desalination efforts. Direct and urgent aspects to be dealt with are analytical and geochemical consequences of the Fukushima Daiichi nuclear disaster. All these cases have one in common – they require reliable thermodynamic data in order to forecast the fate of chemicals in the respective environment. Whereas a variety of standard methods, such as potentiometry, solubility studies, liquid-liquid extraction or electrochemical titrations, are in widespread use to generate thermodynamic data, it is far less straightforward to assign correct reaction pathways and structural patterns to the underlying chemical transformations. This especially holds for systems with strong tendencies to complexation and oligomerization. Here, it is essential to have proof of evidence for all involved species, which cannot be provided by the aforementioned methods, and is still lacking for various metal-containing systems. Spectroscopic techniques in combination with approaches from quantum chemistry can be of great benefit for such tasks. However, their application ranges are often restricted with respect to the type of element (and redox state) that can be probed. Further handicaps are imposed by detection limits or other parameters such as pH or salinity. Moreover, the spectroscopic results are often difficult to interpret in an unambiguous way. To overcome these complications at least partially, this workshop has been initiated. It shall significantly extend the application areas of spectroscopic tools important for lanthanide and actinide chemistry. Emphasis shall be placed on the development of spectroscopic methods towards more challenging environmental conditions – such as very basic pH values, elevated temperatures, pressures, or salinities – extending the range of covered elements and redox states. Furthermore, the exploration of options for lowering detection limits and increasing spatial resolution at sufficiently high signal-to-noise ratios will support future investigations on more complex systems. An approach combining the extension of spectroscopic tools with respect to elements and parameters, improvements of experimental setups, and applications of quantum chemical methods in predictive as well as interpretative ways certainly can be very beneficial. The workshop hopefully will bundle and strengthen respective research activities and ideally act as a nucleus for an international network, closely collaborating with international partners. I am confident that the workshop will deliver many exciting ideas, promote scientific discussions, stimulate new developments and in such a way be successful.

Zugl.: Hamburg, Helmut-Schmidt-Univ., Diss., 2007

Im Grundwasser des radioaktiven Endlagers Tomsk-7, Sibirien, Russland wurde die mikrobielle Diversität mittels der 16Sr DNA-Analyse untersucht. Die Ergebnisse zeigen die Dominanz von Betaproteobakterien, Bacteroidetes und einer neuen "Cyanobacteria-ähnlichen" Gruppe. Methanogene und verschiedene Cluster von Crenarcheota bestimmen die Archaeenpopulation. Autotrophe Bakterien wurden mit der RubisCO-Methode identifiziert und damit die Dominanz der Betaproteobakterien bestätigt. Aus den Gruppen der Alphaproteo- und Aktinobakterien wurden oligotrophe Bakterien isoliert. Diese tolerieren relativ hohe Konzentrationen unterschiedlicher Schwermetalle und wechselwirken effektiv mit Uran. EXAFS-Analysen haben gezeigt, dass bei pH 4,5 die Stämme U(VI) in Form von meta-Autunite immobilisieren. Bei pH 2 wurde das Uran an organische Phosphatreste gebunden. In der Umgebung des Endlagers Tomsk-7 wurden damit Mikroorganismen gefunden, die ein hohes Potential zur Bindung und zum Transport von Radionukliden haben.

Techn. Universiẗat, Diss., 2005--Darmstadt.

The Institute of Safety Research (ISR) is one of the six Research Institutes of Forschungszentrum Dresden-Rossendorf e.V. (FZD), which is a member institution of the Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz (Leibnizgemeinschaft). Together with the Institutes of Radiochemistry and Radiation Physics, ISR implements the research programme „Nuclear Safety Research“, which is one of the three scientific programmes of FZD. The programme includes two main topics, i. e. “Safety Research for Radioactive Waste Disposal” and “Safety Research for Nuclear Reactors”.

Modern Societies have to consider diverse tasks strongly related to geochemistry sciences. Examples intensively discussed in the public are restoration measures for contaminated industrial fallow grounds, the safe storage of chemical-toxic and radioactive waste, carbon dioxide sequestration to reduce green-house gas emissions, the construction and operation of deep geothermal power plants, the geochemical exploration of natural resources or water and waste water treatments, including desalination efforts. Direct and urgent aspects to be dealt with are analytical and geochemical consequences of the Fukushima Daiichi nuclear disaster. All these cases have one in common – they require reliable thermodynamic data in order to forecast the fate of chemicals in the respective environment. Whereas a variety of standard methods, such as potentiometry, solubility studies, liquid-liquid extraction or electrochemical titrations, are in widespread use to generate thermodynamic data, it is far less straightforward to assign correct reaction pathways and structural patterns to the underlying chemical transformations. This especially holds for systems with strong tendencies to complexation and oligomerization. Here, it is essential to have proof of evidence for all involved species, which cannot be provided by the aforementioned methods, and is still lacking for various metal-containing systems. Spectroscopic techniques in combination with approaches from quantum chemistry can be of great benefit for such tasks. However, their application ranges are often restricted with respect to the type of element (and redox state) that can be probed. Further handicaps are imposed by detection limits or other parameters such as pH or salinity. Moreover, the spectroscopic results are often difficult to interpret in an unambiguous way. To overcome these complications at least partially, this workshop has been initiated. It shall significantly extend the application areas of spectroscopic tools important for lanthanide and actinide chemistry. Emphasis shall be placed on the development of spectroscopic methods towards more challenging environmental conditions – such as very basic pH values, elevated temperatures, pressures, or salinities – extending the range of covered elements and redox states. Furthermore, the exploration of options for lowering detection limits and increasing spatial resolution at sufficiently high signal-to-noise ratios will support future investigations on more complex systems. An approach combining the extension of spectroscopic tools with respect to elements and parameters, improvements of experimental setups, and applications of quantum chemical methods in predictive as well as interpretative ways certainly can be very beneficial. The workshop hopefully will bundle and strengthen respective research activities and ideally act as a nucleus for an international network, closely collaborating with international partners. I am confident that the workshop will deliver many exciting ideas, promote scientific discussions, stimulate new developments and in such a way be successful.

Im Grundwasser des radioaktiven Endlagers Tomsk-7, Sibirien, Russland wurde die mikrobielle Diversität mittels der 16Sr DNA-Analyse untersucht. Die Ergebnisse zeigen die Dominanz von Betaproteobakterien, Bacteroidetes und einer neuen "Cyanobacteria-ähnlichen" Gruppe. Methanogene und verschiedene Cluster von Crenarcheota bestimmen die Archaeenpopulation. Autotrophe Bakterien wurden mit der RubisCO-Methode identifiziert und damit die Dominanz der Betaproteobakterien bestätigt. Aus den Gruppen der Alphaproteo- und Aktinobakterien wurden oligotrophe Bakterien isoliert. Diese tolerieren relativ hohe Konzentrationen unterschiedlicher Schwermetalle und wechselwirken effektiv mit Uran. EXAFS-Analysen haben gezeigt, dass bei pH 4,5 die Stämme U(VI) in Form von meta-Autunite immobilisieren. Bei pH 2 wurde das Uran an organische Phosphatreste gebunden. In der Umgebung des Endlagers Tomsk-7 wurden damit Mikroorganismen gefunden, die ein hohes Potential zur Bindung und zum Transport von Radionukliden haben.

Im Mai 2017 wurde das „Gesetz zur Suche und Auswahl eines Standortes für ein Endlager für hochradioaktive Abfälle“ (Standortauswahlgesetz -StandAG) vom Bundestag und Bundesrat neu verabschiedet. In diesem Gesetz sind sämtliche Kriterien (geowissenschaftliche Kriterien, planungswissenschaftliche Kriterien, Kriterien für Sicherheitsuntersuchungen) erstmals gesetzlich festgelegt, die für die zukünftige Auswahl eines Standortes für ein Endlager für hoch radioaktive Wärme entwickelnde Abfälle (ausgediente Brennelemente und Abfälle aus der Wiederaufarbeitung bestrahlter Brennelemente) in Deutschland gelten. Die Kriterien sind vorab durch die „Kommission Lagerung hochradioaktiver Abfallstoffe“ (Endlagerkommission) in zweijähriger Arbeit von 2014 bis 2016 in kontroverser Diskussion festgelegt worden. In diesem Beitrag werden die geowissenschaftlichen Kriterien und die Phasen im Standortauswahlverfahrens kurz vorgestellt. Der Autor war Mitglied der Endlagerkommission. / In May 2017, the 'Act on the Search for and Selection of a Site for a Repository for Highly Radioactive Waste' (Site Selection Act - StandAG) was passed by the German “Bundestag” and “Bundesrat”. This Act for the first time defines by law all the criteria (geoscientific criteria, planning criteria, criteria for safety investigations) that apply to the future selection of a site for a repository for high-level radioactive, heat-generating waste (spent fuel elements and waste from the reprocessing of spent fuel elements) in Germany. The criteria have been defined in advance by the 'Commission on the Storage of Highly Radioactive Waste Materials' (Final Storage Commission; “Endlagerkommission”) in a controversial discussion during two years of work from 2014 to 2016. In this article, the geoscientific criteria and the phases in the site selection process are briefly presented. The author was member of the Repository Commission.