► Kristina Brix
Kristina Brix, M. Sc.
BMWi joint project GRaZ I and GRaZ II: "Geochemical radionuclide retention at cement aging phases".
Retention of repository-relevant elements at calcium bentonite and cement aging phases
Nowadays, one of the major tasks for humanity is the development of a high level nuclear waste (HLW) disposal in deep geological formations. In order to ensure the compliance with safety standards for more than a hundred thousand years, it is essential to know the important interaction processes between the radioactive waste and the surrounding formations. In Germany, granite, salt and clay are considered as possible host rocks. Besides this natural barrier, preventing radioactive elements to contaminate the surrounding area, some technical barriers were also used. One of these barriers is calcium bentonite as a mixture of several clays, used as potential buffer material and borehole seal. The retention of elements relevant for high level waste disposal on calcium bentonite gets investigated via mass spectrometry with inductively coupled plasma (ICP-MS) for long term safety assessment considering different geochemical parameters like pH value and ionic strength.
The research work in GRaZ II relates in particular to the interactions of radionuclides and their homologues with cement or concrete and their alteration products within the geotechnical barrier of a potential repository under the influence of high-saline and hyperalkaline conditions. The main focus is to investigate the behaviour of repository-relevant elements or element mixtures under different geochemical conditions (formation waters, cement additives and competing ions). The selected elements are U(VI) as nuclear fuel or Mo(VI) as a possible homologous element, Eu(III) as a representative for the trivalent actinides, and Cs(I), Sr(II), Pd(II), Sm(III), Zr(IV) and Ru(IV) as possible degradation or fission products, as structural parts (e.g. cladding tubes or ingot moulds) and as non-radioactive homologous representatives. In addition to single-element experiments, the investigations are mainly carried out with element mixtures ("WASTe cocktail") using multi-element ICP-MS in the concentration range from 10-9 to 10-5 mol/L.
Brix, K., Baur, S., Haben, A., Kautenburger, R. (2021) Building the bridge between U(VI) and Ca-bentonite – Influence of concentration, ionic strength, pH, clay composition and competing ions. Chemosphere, 131445.
Meyer, A.M., Fünfrocken, E., Kautenburger, R., Cairault, A., & Beck, H. P. (2021) Detecting pollutant sources and pathways: High-frequency automated online monitoring in a small rural French/German transborder catchment. Journal of Environmental Management 290, 112619.
Fischer, T., Tschernig, T., Drews, F., Brix, K., Meier, C., Simon, M., Kautenburger, R., Schneider, M. (2021) SiRNA delivery to alveolar macrophages using aspherical, nanostructured microparti-cles as gene delivery system. European Journal of Pharmaceutics and Biopharmaceutics 158, 284-293.
Müller, D.W., Lößlein, S., Terriac, E., Brix, K., Siems, K., Moeller, R., Kautenburger, R., Mücklich, F. (2020) Increasing Antibacterial Efficiency of Cu Surfaces by targeted Surface Functionalization via Ultrashort Pulsed Direct Laser Interference Patterning (USP-DLIP). Advanced Materials Interfaces 2020, 2001656.
Brix K, Hein C, Haben A, Kautenburger R (2019) Adsorption of caesium on raw Ca-bentonite in high saline solutions: Influence of concentration, mineral composition, other radionuclides and modelling. Applied Clay Science, 182, 105275.
Kautenburger R, Brix K, Hein C (2019) Insights into the retention behaviour of europium(III) and uranium(VI) onto Opalinus Clay influenced by pore water composition, temperature, pH and organic compounds. Applied Geochemistry, 109, 104404.
Brix K, Hein C, Sande, JM, Kautenburger R (2017) Simultaneous quantification of iodine and high valent metals via ICP-MS under acidic conditions in complex matrices. Talanta 167, 532-536.
► Conference contributions
PD Dr. Ralf Kautenburger
+49-(0)681 302 2171
Kontakt und Anfahrt:
Universität des Saarlandes
Anorganische Chemie / Elementanalytik
Campus C4 1, 1. UG