Origin of enriched uranium contained in Japanese atmospheric deposits

Yoshikazu Kikawada, Kohei Oda, Masao Nomura, Teruyuki Honda, Takao Oi, Katsumi Hirose, Yasuhito Igarashi

1Department of Materials and Life Sciences, Sophia University, Tokyo, Japan;.
Atomic Energy Research Laboratory, Tokyo City University, Kawasaki, Japan.
Department of Materials and Life Sciences, Sophia University, Tokyo, Japan;.
Meteorological Research Institute, Tsukuba, Japan.
Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo, Japan.

DOI: 10.4236/ns.2012.431122                

Abstract

The chemical compositions of atmospheric deposits collected in Fukuoka, Japan, in 1964 and 2000, which are known to have high ²³⁵U/²³⁸U 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 ²³⁵U/²³⁸U 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 ²³⁵U/²³⁸U 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.

Keywords

Atmospheric Deposit; Enriched Uranium; Uranium Isotope Ratio; Nuclear Test; Anthropogenic Radionuclides

Conflicts of Interest

The authors declare no conflicts of interest.

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