At the time of the occurrence of the Tokai earthquake, serious damage is expected in the large range.
Fig. 22 is an earthquake disaster-measures strengthening area (as of February, 2002) by the Large-Scale Earthquake Countermeasures Act. ( Hamaoka is situated in the red circle. )
In the strengthening area, an official announcement of watch declaration of the occurrence of an earthquake is to carry out refuge from a dangerous area, traffic restriction, etc.
However, about the nuclear power plants of Hamaoka, it is only said like "electricity supplies" and there is no rule about this. According to Chubu Electric Power and the Ministry of International Trade and Industry, when a watch declaration of "Tokai earthquake occurrence is issued, seeing the supply-and-demand situation of electric power, they will correspond to stop the nuclear reactors.
When there is doubt about the occurrence of an earthquake, we have to stop them immediately.
At a nuclear power plant, we must continue turning cooling water after it stops. The power supply to do it is the electricity from the power line from outside, or from the diesel dynamo for emergencies. Even we can stop it, if cooling goes wrong by a fracture of piping and power failure at an earthquake, a big accident will happen.
The amount of generating of collapse heat decreases with time, 1 hour
after, to 1/5 and 12 hours after, falls to 1/10. The difference may become
the turning point of how far the accident is expanded. There cannot be
a moment to lose to hesitate to stop it.
Even for or the researchers, it is inexperienced thing what phenomenon comes out just before the Tokai earthquake. The former Tokai earthquake happened in 1854.
However, even if the forecast is not able to succeed just
before the earthquake, the detailed observation record of its surveys,
base rock distortion, micro earthquakes, and the water level of deep
wells, these all will be useful for the future generations who have
to prepare for the following Tokai and southeast sea earthquake in 100
to 200 years.
Damage assumption of the Tokai earthquake
Fig. 23 is damage assumption of Shizuoka by Shizuoka Prefecture. The location of nuclear power plants of Hamaoka is added. It will be carried out in 1990 to 93 before the Hyogo southern part earthquake.
The scale of the earthquake is magnitude 8. The conditions are; the lunchtime in spring or autumn, tide is in, and 5m [/second] wind velocity, in the case of no forecast and watch declaration.
There is also an estimate when there is watch declaration. Does it really end owing to damage of this level? In damage assumption announced in May 2001, for the case that it happened at 5:00 a.m. it was changed like the next table.
Seismic intensity 7 zones are near the nuclear power plants of Hamaoka. If there is on the lee at the big accident and you remain there, the people will be killed in radioactivity immediately.
At an earthquake, you have to take refuge quickly. However, probably, traffic and communication have also stopped. Moreover, radioactivity is not visible. The following figure shows the damage assumption of nearby prefectures. Radioactivity surpasses adjoining prefectures and flows to a long distance more.
Please refer to this URL for details. (Japanese)