According to the damage estimation (NHK [1]), the height of the tsunami in Ikata and in Hamaoka is 20 meters. The Ikata nuclear power plant is built on the top of the Median Tectonic Line. Hamaoka nuclear power plant is built on the top of the boundaries among three tectonic plates (Figure 2). However, in Ikata the No 3 reactor is still running and 770 tons of the spent fuel is stored in the cooling pool. In Hamaoka, 1,130 tons of the spent fuel is stored in the cooling pool.

According to the homepage of Chubu Electric Power (Chubu Electric Power [2]), they increased the earthquake resistance of the Hamaoka nuclear power plant up to 1200 gal and added the breakwater which is 22 meters from sea level. However, 1200 gal is not enough. Hamaoka nuclear plant is located on the top of the three tectonic plates boundaries and the seismic source zone might be directly underneath the plants. There were many earthquakes with much larger gal, such as 2933 gal in the Tohoku earthquake in 2011 and 2828 gal in the Noto earthquake in 2024. We are anticipating a much more fierce quake in the Nankai Trough Earthquake. The 22 meter breakwater is not enough either. Due to the special geologic location of Hamaoka, the actual tsunami might be 30-40 meters. What we have learned from the 2011 Tohoku earthquake is that the only way to survive from a tsunami is just running away from it. In Taro in Iwate, people had constructed a gigantic breakwater of 10 meters high and 2 kilometers long to defend their town, but the actual tsunami came far beyond the breakwater and destroyed it like pudding.

There are two ways to store the spent nuclear fuel, cooling pool and dry cask. In the cooling pool, the loss of electricity will cause the meltdown of the fuel within three days. After a couple of years of cooling period in the pool, the spent nuclear fuel can be stored in dry casks without electricity. Therefore the best solution for the storage of the spent nuclear fuel is to use the dry casks.

We have to solve the problems of Ikata and Hamaoka first. 1900 (1130 + 770) tons of the spent fuel is stored in the cooling pools. Figure 3 shows (the stored spent nuclear fuel / the storage capacity) (in ton unit) in the cooling pools in each nuclear power plant. There are 2150 tons (670 (Tomari) + 340 (Higashidori) + 550 (Kashiwazaki-kariwa) + 590 (Shika)) of storage space left in the cooling pools in other nuclear power plants. Therefore the easiest solution would be to use it to store the spent fuel in Ikata and Hamaoka. Another (better) solution is to store the 1900 tons of the spent fuel in dry casks, which would cost about 30 billion yen (300 million dollars). We have to stop the active reactor in Ikata now. Then the fuel retrieved from the reactor should be sent to a safer cooling pool such as the Shimane nuclear plant.

Currently we still have the following dangers in the south part of Japan:
1. 11 active nuclear reactors (excluding Ikata)
2. A huge amount of spent nuclear fuel stored in the cooling pools in those plants
3. Plutonium (400 kg) in Monju

According to the damage estimation (NHK [1]) those nuclear facilities look relatively safe. However, if big earthquakes occur at the Median Tectonic Line which is the north end of the strong earthquake fault zone of the Nankai Trough Earthquake (Figure 1, Cabinet office[3]), the strong quake would hit the those reactors and the cooling pools. The earthquake‐resistant limits of the nuclear power plants in Japan are only M6.5 (620 Gal – 1200 Gal). Therefore the best solution is the following:

1. to stop the 11 active reactors and transfer the nuclear fuel retrieved from the reactors to safer cooling pools such as the ones in the north part of Japan using the transportation casks,
2. to use dry casks to store the spent fuel in the cooling pools
3. to move the plutonium (400 kg) in Monju to a safe place such as the Rokkasho reprocessing plant.
(For details, please refer to “Research for Nuclear Crisis” section.)

First we need to solve the obvious dangers in Ikata and Hamaoka. Then we should continue to eliminate other danagers. To show our determination, we would like to donate the dry casks and the transportation casks to the nuclear power plants in the south part of Japan. Please help us with your support and your donation.