このエントリーをはてなブックマークに追加
ID 25982
file
creator
Gauthier-Lafaye, François
NDC
Earth sciences. Geology
abstract
Ba isotopic studies of the Oklo and Bangombe natural fission reactors in east Gabon provide information on the geochemical behavior of radioactive Cs (135Cs and 137Cs) in a geological medium. Large isotopic deviations derived from fissiogenic Ba were found in chemical leachates of the reactor uraninites. The fissiogenic Ba isotopic patterns calculated by subtracting the non-fissiogenic component are classified into three types that show different magnifications of chemical fractionation between Cs and Ba. In addition, the isotopic signatures of fissiogenic 135Ba, 137Ba and 138Ba suggest an early differentiation between Cs and Ba of less than 20 years after the production of fissiogenic Cs and Ba. On the other hand, only small excesses of 135Ba (ε<+1.8) and/or 137Ba (ε<+1.3) were identified in some clay samples, which might have resulted from selective adsorption of 135Cs and 137Cs that migrated from the reactors by differentiation.
journal title
Geochimica et Cosmochimica Acta
volume
Volume 72
issue
Issue 16
start page
4123
end page
4135
date of issued
2008-08-15
publisher
Pergamon
Elsevier Science Ltd.
issn
0016-7037
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
Copyright (c) 2008 Elsevier Ltd
relation url
department
Graduate School of Science