Origin of enriched uranium contained in Japanese atmospheric deposits
- 1 1Department of Materials and Life Sciences, Sophia University, Tokyo, Japan;
- 2 Department of Materials and Life Sciences, Sophia University, Tokyo, Japan;
- 3 Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo, Japan
- 4 Atomic Energy Research Laboratory, Tokyo City University, Kawasaki, Japan
- 5 Department of Materials and Life Sciences, Sophia University, Tokyo, Japan;
- 6 Department of Materials and Life Sciences, Sophia University, Tokyo, Japan;
- 7 Meteorological Research Institute, Tsukuba, Japan
Abstract
The chemical compositions of atmospheric deposits collected in Fukuoka, Japan, in 1964 and 2000, which are known to have high 235 U/ 238 U uranium isotope ratio were determined. High uranium contents relative to that of continental crust were observed for the deposition samples in 1964 together with the high 235 U/ 238 U ratios, which indicated that the origin of uranium is fallout materials due to the large-scale 1961- 1962 nuclear explosions conducted by US and former USSR. The deposits in 2000 were mainly composed of dusts from the East Asia. This suggested that uranium with a high 235 U/ 238 U ratio in the deposits in 2000 has been transported as a component of mineral dust particles contaminated with nuclear debris from nuclear test sites from the East Asian deserts and arid regions by the prevailing wind.
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