The 7th IER Seminar of FY2025 held on December 22, 2025 (Visiting Professor Konoplev)

Institute of Environmental Radioactivity (IER) regularly holds the IER Seminar in which the faculty members report on their research results, with the aim of facilitating their research activities and promoting communication.

In the 7th IER Seminar of this fiscal year that was held on December 22, 2025, Visiting Professor Aleksei KONOPLEV gave a presentation to 13 participating researchers and students as follows.

Visiting Professor Konoplev presented two topics 1) Long-term dynamics of dissolved ¹³⁷Cs in Inkyozaka pond taking into account its seasonal fluctuations, and 2) Long-term decline of ¹³⁷Cs apparent distribution coefficient K_d in Fukushima water bodies reflects CsMPs decomposition resulting in ¹³⁷Cs dissolution. The objective of 1st topic was to suggest process-level model of long-term decline of dissolved ¹³⁷Cs taking into account its seasonal fluctuations and to test it against data set on Inkyozaka pond in the vicinity of FDNPP. The goals of the 2nd part of the talk was to suggest process-level model of long-term decline of ¹³⁷Cs apparent distribution coefficient in water bodies taking into account ¹³⁷Cs leaching from CsMPs; to test the model using existent data set on Okuma ponds and Abukuma River and to estimate critical parameters for water bodies under study.

After the presentation, various questions and comments were raised by participants.