(日経 2012/3/10 10:29)
以下が、フォーリン・アフェアーズに掲載されている菅直人前首相の英文寄稿文。 ちなみに、野田首相の英文寄稿文はこちらのブログ記事に掲載中 『＜野田首相、ワシントン・ポストに寄稿文＞英文の原文を読んでみよう….』
Former Japanese PM Naoto Kan on the Fukushima Disaster
A Changing View of Nuclear Power
By Naoto Kan
March 8, 2012
My father was an engineer, and when I was a child, he told me the story of Prometheus, a famous Greek myth in which Zeus grows angry at Prometheus for giving humans the wisdom of fire, knowledge capable of bringing on disaster. As punishment, Zeus chains Prometheus to a rock, where an eagle pecks incessantly at his liver. Today, I cannot help but remember that story when I think about the development of nuclear technology, a modern-day incarnation of the wisdom of fire.
In college, I studied science and technology, and ever since, I have had a great admiration for the Pugwash conferences, a forum dedicated to the elimination of nuclear weapons (the group won the Nobel Peace Prize in 1993). That is because nuclear weapons, which have the power to kill large numbers of people indiscriminately, are fundamentally at odds with the purpose of science, which is to contribute to people’s well-being. To put it another way: Nuclear weapons contradict the very nature of humanity. In fact, this concern was the major reason why I aspired to be a political leader.
Long before the accident at the Fukushima Daiichi nuclear power plant, I knew there were serious unresolved issues regarding the safety of nuclear power and the disposal of radioactive waste. I took the position that these issues could be overcome by technology. With adequate safeguards, nuclear power plants could be operated safely and utilized wisely. Especially in recent years, in order to prevent global warming, nuclear power has been an effective replacement to power plants that feed on fossil fuels and pollute the atmosphere. In fact, before Fukushima, Japan had a plan to expand its network of nuclear plants.
Then, while I was serving as prime minister, the Tohoku earthquake occurred at 2:46 PM on March 11, 2011. Immediately, all reactors in operation at Fukushima Daiichi were shut down; nuclear activity there came to a halt. An hour after the earthquake, I received a report from Tokyo Electric Power Company (TEPCO) stating that several power generators at the Fukushima site were experiencing a total loss of power. An hour after that, there was an accident that suspended the cooling function. The earthquake had toppled the steel towers supporting power transmission lines. Saltwater damage rendered the emergency diesel generators inoperable. All power sources had been lost.
I was fully aware that total power loss and the suspension of cooling functions could then cause a meltdown and lead to further serious accidents such as the destruction of the reactor and the release of radioactive materials into the atmosphere. We took every possible precaution, but our preparedness against total power loss proved insufficient. Over the next five days, Units 1, 2, and 3 melted down. Later, hydrogen explosions occurred inside the building of Units 1, 3, and 4. Fuel pools, used to store spent fuel, adjoin each reactor, and at one time, there was a possibility of the meltdown of this fuel pool, too. In the event of the meltdown of the fuel pools, a large amount of radioactive materials would have been discharged into the atmosphere, and if it continued, the evacuation of the entire metropolitan area, including Tokyo, might have been necessary.
If the reactors and spent fuel pools had gotten out of control, an enormous amount of radioactive material, possibly even several times more than the Chernobyl accident, would have been discharged into the atmosphere, impacting neighboring countries. To prevent this from happening was our responsibility as a nation. I was determined to fight to resolve the accident until the very end and at any cost, including the risk of my own life.
The invisible menace of radioactivity would have seized Tokyo. The city is our nation’s political and economic nerve center. Some 30 million people live in the metropolitan area. The impact of evacuating them all would have been immense. The impact on not only political matters but also the economy and human lives would have been immeasurable.
Fortunately, thanks to the life-risking efforts by TEPCO personnel, Japan’s Self-Defense Forces, and local fire and police departments, injecting water into the reactors and fuel pools prevented further meltdowns and brought the entire accident under control. A very bad situation was narrowly prevented from becoming an accident of catastrophic proportions.
This accident was a war with an invisible enemy. The worst case scenario would have brought serious harm to the nation of Japan as well as a considerable inconvenience to its neighbors.
I have thought very hard about the types of safety measures necessary to prevent any such disaster from happening again. However, when one weighs these measures against the tremendous risks, it is clear that no amount of precautions will make a country completely safe from nuclear energy. I have reached the conclusion, therefore, that the only option is to promote a society free of nuclear power. My administration, as a result, changed its policy to reduce Japan’s dependency on nuclear power, and the current administration is basically following the same policy.
Furthermore, the final disposal of high-level radioactive waste, which needs to be isolated from humans for more than 100,000 years before decaying to a safe level, is a serious issue. Far into the future, it is possible that current nations or boundaries could look very different. Therefore, we need to address whether responsibility for final disposal should rest solely with each nation. Although the International Atomic Energy Agency (IAEA) currently states that the onus lies with each country, many nations, including Japan, do not have any clear solutions.