Japan Geoscience Union Meeting 2022

Presentation information

[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-AG Applied Geosciences

[M-AG39] Radioisotope migration: New development for dynamics study of radionuclides from 1F NPP accident

Mon. May 23, 2022 1:45 PM - 3:15 PM 202 (International Conference Hall, Makuhari Messe)

convener:Daisuke Tsumune(Central Research Institute of Electric Power Industry), convener:Yuichi Onda(Center for Research on Isotopes and Environmental Dynamics, University of Tsukuba), Yoshio Takahashi(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), convener:Akira Kirishima(Tohoku University), Chairperson:Daisuke Tsumune(Central Research Institute of Electric Power Industry), Akira Kirishima(Tohoku University)

2:45 PM - 3:00 PM

[MAG39-05] Changes in groundwater level and 90Sr concentration distribution before/after drawdown of Cooling Pond water level near Chernobyl Nuclear Power Plant

*Hikaru Sato1, Naoaki Shibasaki2, Dmytro Veremenko3 (1.Centre for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 2.Faculty of Symbiotic Systems Science, Fukushima University, 3.SSE Ecocentre, Chernobyl)

Keywords:drawdown, groundwater, Sr-90 concentration, Cooling Pond, Chernobyl Nuclear Power Plant

In the Chernobyl Nuclear Power Plant (ChNPP), the pumping water from the Pripyat River has been stopped since 2014, and the water level of the Cooling Pond (CP) has declined. In the Fukushima Dai-ichi Nuclear Power Station (FDNPS), countermeasures against the contaminated water by radionuclide have changed the distribution of groundwater level and radionuclide concentration. The artificial drawdown of the CP water level would affect the groundwater level around the CP. Therefore, we used the groundwater level data and 90Sr concentration data measured by the SSE Ecocentre at Chernobyl and the SATREPS project to reveal the changes and the distributions of groundwater level and 90Sr concentration from 2014 to 2019.
The groundwater level around the CP has declined in association with drawdown of the CP water level. The changes in groundwater level distribution showed that the drawdown tends to spread from the CP to the western area of the ChNPP buildings. Further, the difference of the water level between the Pripyat River and the CP became small, which suggests the flow velocity from the CP to the river also became small. The concentration of 90Sr in shallow aquifer (up to 30 m in depth) has slightly increased at some wells located between the Pripyat River and the CP after the drawdown of the CP water level since 2014.
In 2020, new observation wells were installed at depths of 30, 60, and 90 m in the vicinity of the CP. 90Sr concentration has been measured since 2021. The maximum 90Sr concentration from January to June in 2021 was 1,400 Bq/m3 in the shallow aquifer, however the concentration in the lower aquifer (below 30 m in depth) was less than 150 Bq/m3 due to interception by an impermeable layer between the aquifers.