The Inside Story of Hamaoka

- A Visit by Chubu Electric to the Former Chairman of the Coordination Committee for Earthquake Prediction -

January 25, 2002
Shukan Asahi (Weekly Asahi Magazine)

Hamaoka Nuclear Power Plants are located in the center of a focal earthquake region. The siting of these power plants needs a drastic review. This warning by Dr. Kiyoo Mogi, a former professor of Tokyo University, was carried in the editorial of the Shizuoka Shinbun, a local newspaper in Shizuoka prefecture where Hamaoka nuclear power plants are located. Dr. Mogi is an authority on the seismology. He used to be the chairman of Coordination Committee for Earthquake Prediction, a government-affiliated body. Soon after the publication of his article in the newspaper, Chubu Electric employees in charge of this issue visited his house, anxious to provide their explanation to Dr. Mogi.

It was December 18, 2001, when two employees from Chubu Electric visited Mr. Mogi's house in Chiba prefecture with a box of sweets. The two men, offering their business cards showing the titles of manager and vice manager in a section related to nuclear power plants construction, were about to begin their explanation. Then Dr. Mogi started out the conversation with a sarcastic tone. "You are the first people from Chubu Electric I have ever met."

Dr. Mogi is the person who pointed out the danger of the Great Tokai Earthquake in 1969, prior to anybody else in Japan. Since then, he had been the chairman for judging the prediction of the Tokai Earthquake and also the chairman of the Coordination Committee for Earthquake Prediction for a long time. He is known as an authority among the Japanese seismic society. However, Chubu Electric had never asked his opinion in regard to the Hamaoka nuclear power plants that were built on top of the focal region.

The events that related came about since the two accidents in Hamaoka 1, where a pipe was ruptured and then a leakage was found in the pressure vessel. Responding to these accidents, Dr. Mogi concluded that the whole nuclear energy science is losing its reliability. Consequently, he gave the following warnings in the editorial articles in the Shizuoka Shimbun (Shizuoka's Local Newspaper) on Novermber 13 and December 19.

One cannot say that the siting of Hamaoka nuclear power plants cannot be justifiable.

Currently, the Tokai area is considered to be the area of most concern for a future major earthquake by researchers and political administrators, who have been taking various countermeasures. However, in spite of this fact, the Hamaoka nuclear power plants were built one after another as if such a situation had not existed.

Japan's safety myth in regard to the earthquake-resistant structure was collapsed when the highways, etc., were collapsed in the Great Hanshin Earthquake. It would be too late if a nuclear accident took place due to a major earthquake. We need a drastic review on this problem.

He further commented, "I have been concerned about the Hamaoka nuclear power plants but while I was the chairman of the Society for Earthquake Prediction [he retired from his post in April 2001], I was too busy with my work on prediction of the Tokai Earthquake and ways to release information. I came to think about the Hamaoka issue after the two accidents, and I consider this issue as very serious. I believe that it is my duty to continue to speak out on this problem.

Soon after the second editorial was issued, there was a call from Chubu Electric to Dr. Mogi, saying. Please let us explain. The two employees who visited Dr. Mogi made an explanation lasting nearly four hours about the situation of investigating the cause of accidents and the earthquake-resistance structure of Hamaoka 1. Yet, Dr. Mogi made the following comment.

In the end, I could not be persuaded by them on the safety of Hamaoka nuclear power plants. There is not a single country in the world where nuclear power plants were built on a place where an earthquake of magnitude 7 or more could hit. Moreover, the Hamaoka nuclear power plants are standing on top of the area where a magnitude eight class earthquake could hit. This is just extraordinary. When I told this to Chubu Electric employees, they whined, But we do not have any good place for siting nuclear power plants." They were not giving me an explanation about the safety, but an explanation to seek my understanding for their troubled situation.

Indeed, Chubu Electric had gone through a tough time introducing new nuclear power plants. Ashihama nuclear power plants in Mie prefecture, whose original plan came before Hamaoka, were consistently opposed by the local people, and the plan was finally cancelled after 37 years with the submission of the "Total cancellation" by the Mie governor, Mr. Masakiyo Kitagawa. In November last year, there was a referendum on whether to establish a nuclear power plant in Miyama town in Mie, but right before the referendum, the accidents happened in Hamaoka. The opposition counted for more than twice the support, which made an outstanding defeat for the promoters's side.

Yet, Chubu Electric had managed to build four nuclear power plants (currently, a fifth one is under construction), all of which are standing on top of the focal region of the Great Tokai Earthquake.

Meanwhile, there is a strong assumption that the water leakage accident from Hamaoka 1 last year was caused by the aging of the plant. Hamaoka 2, which has the same design as Hamaoka 1, had its operation suspended. It is predicted that restarting the operation of these two plans will be quite a time ahead (Translators Note: Recently, Chubu Electric announced that the operation of Hamaoka 2 will resume in a few months.)

Of course, the Hamaoka nuclear power plants complied with the government's Guidelines for Inspecting the Standard of Earthquake Resistance Design, established in 1981. Hamaoka 1 and 2, which were built before the establishment of the guidelines were examined in accordance with them. The Japanese government, as well as Chubu Electric, sought the experts opinions of experts in the fields of seismology and seismic engineering. Accordingly, Chubu Electric makes the following assertion.

Hamaoka nuclear power plants have a design sufficient for earthquake resistance. Of course this is based on the assumption that the Great Tokai Earthquake will occur. We haven't sought Dr. Mogi's opinion, but we have complied with the standard made by the top experts in their fields, so we are not concerned." (Statement made by Nuclear Control Division of Chubu Electric)

However, Dr. Mogi refused this as follows:

You insist that Hamaoka can resist the Great Tokai Earthquake, but the seismology in use when the guideline was established is now obsolete, and the current seismology is much more advanced. Not only that, but in many cases, we cannot predict natural phenomena. In particular, a magnitude 8 class earthquake occuring in Tokai area would have many unknown aspects, and we suppose that there would be unexpected earthquake motions and a high probability of crust deformation. We cannot accept any unexpected event in any nuclear power plants, and these nuclear power plants are standing on the area where a gigantic earthquake is expected to occur. Therefore, isn't it a reasonable idea that we stop these nuclear power plants? In this way, the authority of the seismology is saying that unexpected events can happen.

When Dr. Mogi was talking with the staff from Chubu Electric, he asked then the following question: Why didn't you come to see me for my opinion even for a single time? Then the following answer came back, we do not know what the situation was in those days, but the former staff in charge of this issue might have thought that they would be rejected by you if they had asked for your opinion in regard to the siting.

When Dr. Mogi was the chairman of the Communication for Earthquake Prediction Society, he negotiated with the National Land Agency and the Meteorological Agency regarding the warning issued by the government on prediction for the Tokai Earthquake, insisting, A warning of black or white is not sufficient. We also need precautionary information. Then, in March 1996, he resigned as chairman saying, I cannot be confident on issuing a predicative information under the current system, expressing his critical view of the government system of earthquake prediction.

Dr. Mogi is the type of demanding scholar who cannot be welcomed by the government officials. Being aware of that himself, he continued, If they say that they didnt ask for my opinions since I was likely to oppose the plan, that means they only asked scholars who always say yes to the government, doesnt it? In regard to the Great Tokai Earthquake, the earthquake prediction and the safety of Hamaoka nuclear power plants are such grave issues, but seismologists never make any comment as if they regard these issues as taboo. However, when I talked to researchers in private, many did say, What Dr. Mogi says is all correct.

Yet Chubu Electric said, We will continue to ask Dr. Mogi to listen to our explanation until he understands our points.

It is not only Dr. Mogi who insists on the dangers of the Hamaoka nuclear power plants in relation to the Great Tokai Earthquake.

Professor Katsuhiko Ishibashi at Kobe University (57), who is also a member of the special Investigation Committee for the Tokai Earthquake in the Conference for Central Governments Disaster Prevention, warned of Genpatsu Shinsai-nuclear disaster caused by earthquake in 1997. He pointed out that nuclear power plants in Japan, particularly Hamaoka, would not withstand gigantic earthquakes, which will result in a total catastrophe. After making his theory public, he visited Hamaoka nuclear power plants and listened to the explanations made by Chubu Electric, but Prof. Ishibashi said, I have never been persuaded by Chubu Electric.

Little by little, more scholars of seismology, physics and other fields have come to point out the danger of nuclear power plants in relation to earthquakes. Maybe it is a good idea to establish a group such as, a Society of Scholars Concerned about Genpatsu Shinsai, with Dr. Mogi as our head."