Publications
Depth profile of U-236/U-238 in soil samples in La Palma, Canary Islands
- Author(s)
- Michaela Srncik, Peter Steier, Gabriele Wallner
- Abstract
The vertical distribution of the U-236/U-238 isotopic ratio was investigated in soil samples from three different locations on La Palma (one of the seven Canary Islands, Spain). Additionally the Pu-240/Pu-239 atomic ratio, as it is a well establish tool for the source identification, was determined. The radiochemical procedure consisted of a U separation step by extraction chromatography using UTEVA (R) Resin (Eichrom Technologies, Inc.). Afterwards Pu was separated from Th and Np by anion exchange using Dowex 1x2 (Dow Chemical Co.). Furthermore a new chemical procedure with tandem columns to separate Pu and U from the matrix was tested. For the determination of the uranium and plutonium isotopes by alpha spectrometry thin sources were prepared by microprecipitation techniques. Additionally these fractions separated from the soil samples were measured by Accelerator Mass Spectrometry (AMS) to get information on the isotopic ratios U-236/U-238, Pu-240/Pu-239 and U-236/Pu-239, respectively. The U-236 concentrations [atoms/g] in each surface layer (similar to 2 cm) were surprisingly high compared to deeper layers where values around two orders of magnitude smaller were found. Since the isotopic ratio Pu-240/Pu-239 indicated a global fallout signature we assume the same origin as the probable source for U-236. Our measured U-236/Pu-239 value of around 0.2 is within the expected range for this contamination source.
- Organisation(s)
- Department of Inorganic Chemistry, Isotope Physics
- Journal
- Journal of Environmental Radioactivity
- Volume
- 102
- Pages
- 614-619
- No. of pages
- 6
- ISSN
- 0265-931X
- DOI
- https://doi.org/10.1016/j.jenvrad.2011.03.011
- Publication date
- 2011
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 104003 Inorganic chemistry, 103014 Nuclear physics, 104023 Environmental chemistry
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/bcee7c4a-37e5-4e92-8d67-c8be3bc5fff9