Japan Geoscience Union Meeting 2023

Presentation information

[J] Oral

U (Union ) » Union

[U-11] Compound Disasters across Atmosphere, Hydrosphere and Geosphere

Mon. May 22, 2023 1:45 PM - 3:15 PM Exhibition Hall Special Setting (1) (Exhibition Hall 8, Makuhari Messe)

convener:Takahiro Sayama(Kyoto University), Takato Takemura(Nihon University), Yoshinori MIYACHI(Geological Survey of Japan, AIST), Yasuhiro Ishimine(Mount Fuji Research Institute, Yamanashi Prefectural Government), Chairperson:Takahiro Sayama(Kyoto University), Takato Takemura(Nihon University), Yoshinori MIYACHI(Geological Survey of Japan, AIST), Yasuhiro Ishimine(Mount Fuji Research Institute, Yamanashi Prefectural Government)

3:00 PM - 3:15 PM

[U11-06] Possibility of a grave accident at a nuclear power plant triggered by a super volcanic eruption

*Yukitoshi Fukahata1 (1.Disaster Prevention Research Institute, Kyoto University)

Keywords:super volcanic eruption, nuclear accident, volcanic ash

The biggest man-made disaster would be a nuclear power plant accident or a war. Although the number of casualties of a gigantic war would be significantly larger than that of a nuclear accident, the effect of a nuclear accident lasts much longer than that of a war, as observed in Fukushima.
The biggest natural disaster would be a super volcanic eruption except for an impact of a giant meteorite. The power of a super volcanic eruption is really devastating. For example, at the time of the Kikai Caldera eruption that occurred about 7.3 ka, the pyroclastic flow crosses the Ohsumi strait and extinguished the Jomon culture flourished in southern Kyushu. It should be noted that super volcanic eruptions do occur with a frequency that cannot be ignored; they have occurred at least 3 times in Kyushu in recent 100 thousand years. Considering on average, this probability is higher than the probability of a particular person (e.g., myself) dying in a car accident.
If a super volcanic eruption occurred in southern Kyushu, Sendai nuclear power plant would be seriously damaged; if it occurred at the Aso caldera, Genkai and Ikata nuclear power plants would be. At such a super volcanic eruption, volcanic ashes also falls in Tokyo and Osaka areas with several to a few tens of centimeters. If radioactive materials were mixed in volcanic ashes, the situation would be beyond our imagination.
We should seriously consider the risk of a nuclear accident triggered by a super volcanic eruption. If it happened, the existence of the nation of Japan could be questioned.