CHARACTERISATION OF RADIOACTIVE CAESIUM IN SEDIMENTS AT THE NOGAWA RIVER, JAPAN
Satoshi Inose1, Yusuke Nanri2, Rintaro Saito1
1Applied Chemistry Course, Graduate School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan.
Radiation Protection Dosimetry
|September 9, 2022
Summary
Radioactive caesium (137Cs) from the Fukushima Daiichi Nuclear Power Plant accident is accumulating in river sediment. Its downstream migration is limited, strongly correlating with organic matter and clay-silt content.
Area of Science:
- Environmental Science
- Radiochemistry
- Geochemistry
Background:
- The 2011 TEPCO Fukushima Daiichi Nuclear Power Plant accident released radioactive caesium into the environment.
- Radioactive caesium has been detected within the Tama River watershed, with previous studies noting high concentrations in Nogawa River sediment.
Purpose of the Study:
- To investigate the relationship between radioactive caesium concentration in sediment and sediment characteristics.
- To understand the migration patterns of radioactive caesium in the Nogawa River tributary.
Main Methods:
- Analysis of radioactive caesium (137Cs) concentration in tributary sediment.
- Correlation analysis between 137Cs concentration and sediment characteristics such as organic matter, clay, and silt content.
Main Results:
- 137Cs concentration in tributary sediment showed limited downstream migration.
- A strong positive correlation was observed between 137Cs concentration and organic matter content.
- A correlation was also found between 137Cs concentration and the presence of clay and silt layers.
Conclusions:
- 137Cs is deposited in sediment along with organic matter and clay-silt components.
- The migration of 137Cs in the tributary sediment is slower compared to the mainstem, influenced by sediment composition.
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