Overview
A research paper by a team consisting of Hikaru Sato, Professor Yuichi Onda and Professor Daisuke Tsumune from the University of Tsukuba, and Katsuhiko Kohata and Tomomi Okamura from Tokyo Electric Power Company Holdings, Inc. has been published and press released. ※Press release document (PDF 5.21MB)
This study identified the source and fluctuation factors of radioactive cesium-137 (¹³⁷Cs) flowing into the harbor of the Fukushima Daiichi Nuclear Power Plant via its drainage channels. By utilizing tritium (³H) in groundwater—originating from tank water leaks—as a hydrological tracer, the research revealed that approximately 50% of the ¹³⁷Cs originates from rainwater that fell on the reactor buildings, referred to as “roof drainage.”
Publication Information
Leaked Tritium Reveals the Source of 137Cs from the Fukushima Daiichi Nuclear Power Plant to the Ocean
Sato, H., Onda, Y., Tsumune, D., Kohata, K., Okamura, T., Leaked tritium reveals the source of 137Cs from the Fukushima Daiichi Nuclear Power Plant to the ocean, Water Research, 2025, DOI:10.1016/j.watres.2025.124464 (Y-24-01,Y-25-02)