Publikationen

Depth profile of U-236/U-238 in soil samples in La Palma, Canary Islands

Autor(en)
Michaela Srncik, Peter Steier, Gabriele Wallner
Abstrakt

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(en)
Institut für Anorganische Chemie, Isotopenphysik
Journal
Journal of Environmental Radioactivity
Band
102
Seiten
614-619
Anzahl der Seiten
6
ISSN
0265-931X
DOI
https://doi.org/10.1016/j.jenvrad.2011.03.011
Publikationsdatum
2011
Peer-reviewed
Ja
ÖFOS 2012
104003 Anorganische Chemie, 103014 Kernphysik, 104023 Umweltchemie
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/depth-profile-of-u236u238-in-soil-samples-in-la-palma-canary-islands(bcee7c4a-37e5-4e92-8d67-c8be3bc5fff9).html