Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
1 PublicationStructural determination of neptunium redox spezies in aqueous solution
Ikeda-Ohno, A.; Hennig, C.; Rossberg, A.; Funke, H.; Scheinost, A. C.; Bernhard, G.; Yaita, T.
Abstract
Neptunium (93Np) is one of the most important elements to be considered for the geological disposal of high-level radioactive wastes, because of a considerable content in the wastes, and the high radioactivity, half-lives and radiotoxicity of its nuclides. From a chemists point of view, it is also a very interesting element because of its diversity of oxidation states from III to VII [1]. Whether Np may be retained in the waste repository for millions of years, or whether it will migrate to the biosphere, depends heavily on its chemical forms (speciation). We assume that oxidation state will have a strong influence on the speciation. Therefore detailed knowledge about the interrelation between oxidation state and the structure of chemical species is critical for the development of safe nuclear waste repositories. This motivated us to perform X-ray absorption fine structure (XAFS) studies to determine the complex structure of Np species in aqueous solutions at different oxidation states. The experiments were performed at the Rossendorf Beamline (BM20), the only beamline at the ESRF, where such studies with aqueous Np samples can be performed.
Keywords: Neptunium; EXAFS
-
Contribution to external collection
G. Admans: ESRF Highlights, Grenoble: European Synchrotron Radiation Facility, 2009, 99-100
Permalink: https://www.hzdr.de/publications/Publ-13350
Years: 2023 2022 2021 2020 2019 2018 2017 2016 2015