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Design and Construction of an Urban Runoff Research Facility
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CESIUM-RICH MICROPARTICLES RUNOFF DURING RAINFALL: A CASE STUDY IN THE TAKASE RIVER
Takahiro Tatsuno1, Hiromichi Waki2, Minato Kakuma2
1Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan.
Radiation Protection Dosimetry
|September 9, 2022
Summary
Cesium-rich microparticles (CsMPs) carrying radioactive cesium-137 (137Cs) were studied for river runoff after the Fukushima accident. CsMPs were rarely found in river water, indicating minimal CsMP runoff from forests to the Takase River.
Area of Science:
- Environmental Science
- Radiochemistry
- Geochemistry
Background:
- Cesium-rich microparticles (CsMPs) containing radioactive cesium-137 (137Cs) were released following the Fukushima Daiichi Nuclear Power Plant accident.
- These CsMPs deposited on surface soil, posing a risk of entering river systems through soil erosion during rainfall.
Purpose of the Study:
- To investigate the runoff of CsMPs via soil erosion during rainfall events.
- To quantify the contribution of CsMPs to the total radioactive cesium (137Cs) transported in river water.
Main Methods:
- Water samples were collected during four rainfall events between February and July 2021 in the Takase River watershed.
- Suspended solids (SS) in the water samples were analyzed for the presence and concentration of CsMPs and 137Cs.
Main Results:
- CsMPs were infrequently detected in the suspended solids of river water samples.
- On average, CsMPs accounted for approximately 6% of the total particulate 137Cs concentration in the water.
Conclusions:
- The study suggests that the runoff of CsMPs from forest areas to the Takase River is limited.
- The contribution of CsMPs to the overall 137Cs transport in this river system during rainfall is relatively small.
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