To the Slides
IUGG2003/JSP11/07P/A10-002
Geophysical Risk and Vulnerability: The Population-Hazard Interaction

Genpatsu-Shinsai: Catastrophic Multiple Disaster of Earthquakeand Quake-induced Nuclear Accident Anticipated in the Japanese Islands
Katsuhiko ISHIBASHI
Department of Earth and Planetary Sciences, Faculty of Science, Kobe University, Kobe, JapanThe most serious factor of civilized infrastructure that has maximized vulnerability toearthquakes in Japan is a cluster of nuclear power plants distributed all along the coastlines of
the world's most earthquake-prone archipelago. At present, 16 commercial nuclear power
stations with 52 large-scale reactors are being operated in tiny and densely-populated islands.
The most dangerous nuclear power station is Hama'oka located just above thehypothesized huge fault plane of the impending M8-class Tokai earthquake on the Pacificcoast of central Japan. If this earthquake, a nationwide concern and the subject of a special
countermeasures act, happens, the seismic disaster will definitely be devastating in a broad
area between Tokyo and Nagoya with officially estimated collapsed buildings of more than
200 thousands and with huge tsunami. If this earthquake causes a severe accident to theHama'oka station with massive leakage of radioactivity outside, then the rescue andrestoration works in the earthquake disaster area become impossible, and at the same time,
management of the nuclear accident and evacuation of inhabitants from radioactivity are
extremely difficult due to the earthquake damages. Therefore, the nuclear accident would beleft to expand to the maximum scale and victims of radiation exposure and ordinary
earthquake disaster would become numerous. Even a few tens of million inhabitants aroundTokyo, nearly 200 km away from Hama'oka, would be forced to evacuate. I call this disasterof earthquake-nuclear complex as <Genpatsu (nuclear power plant)-Shinsai (earthquakedisaster)>, which is a totally new type of natural-manmade disaster that the human beings
have never encountered. Its final effect will be global as well as a fatal blow to Japan, andaffect deeply future generations.
The authorities concerned claim that the aseismic measures of Japanese nuclear power
plants are perfect and all plants and related atomic facilities are safe against any kind ofearthquake. But, construction of nuclear power plants in Japan was started around the early
1960's, just on the eve of the birth and spread of two basic theory of modern earthquake
science, fault model of earthquakes and plate tectonics. Therefore, the official standards ofaseismic design of nuclear facilities are oldish and insufficient in view of modern earthquake
sciences. Not only Hama'oka but also most other nuclear power stations in Japan seem
accident-prone due to large earthquakes, because many are located in seismic gaps with clear
active faults or just above subducted oceanic plates where large slab earthquakes may occur.
These kinds of scientific matters were not taken into account during planning andconstruction of plants.
In order to avoid Genpatsu-shinsai we should first face this problem squarely and assess
its risk as objectively as possible. I think this serious vulnerability of modern society is not
restricted in Japan but should also be a global concern.
Presented in Session JSP11 in the 23rd. General Assembly of
the International Union of Geodesy and Geophysics, 2003, Sapporo, Japan