Fukushima: A Global Issue
Nuclear expert, philosopher, strategist, social entrepreneur and former advisor to Prime Minister Kan, Dr. Hiroshi Tasaka shares his views on Japan’s nuclear crisis.
Why should Japan stop relying so heavily on nuclear energy? The answer is simple. There is a backend problem in the nuclear fuel cycle that doesn’t allow for the final disposal of nuclear waste in the country.
The Science Council of Japan, the highest authority of academia in the country, submitted an official recommendation to the Japanese government on September 11, 2012 arguing that the geologic disposal of nuclear waste should not be carried out in Japan because current science cannot prove its long-term safety.
Geologic disposal involves isolating nuclear waste from the human environment by burying it in a deep and stable geologic formation more than 300 meters underground.
Nuclear waste includes spent nuclear fuel (SF) and high-level radioactive waste (HLW) generated through the reprocessing process of spent nuclear fuel.It takes more than 100,000 years for the radioactive toxicity of SF and more than 30,000 years for the radioactive toxicity of HLW to decrease to a level lower than the toxicity of a natural uranium mine.
To ensure the long-term safety of the geologic disposal of nuclear waste, we need to demonstrate the long-term stability of the geologic formation and the migration rate of groundwater for more than 100,000 years.
However this is very difficult to do in Japan due to earthquake and volcanic activity. Even in countries with stable geologic formations, it is difficult to demonstrate the long-term safety of geologic disposal because of the possibility of the “human intrusion scenario” that comes with mining or underground development.
If we cannot carry out the geologic disposal of nuclear waste, we should not continue to operate nuclear power plants since the capacity of Japan’s SF storage pools will reach their limit in approximately six years. Anti-nuclear supporters have compared this situation to having a “mansion without a toilet.”
So what can we do with the SF piling up in each power plant? The Science Council of Japan recommended to the Japanese government that we should change the policy for SF and HLW from “geologic disposal” to “long-term storage” for hundreds of years until newly developed science ensures the long-term stability of geologic formations or newly developed technology creates other ways to dispose of it such as with space disposal or transmutation processing.
But if we change the policy from geologic disposal to long-term storage, we have to set the maximum limit of the total generated amount of SF or HLW.
Such a decision would naturally result in the maximum number of operable years for nuclear power plants. So when we consider these facts and reality, we can understand that a nuclear-free society is not the problem of “political choice” but of “unavoidable reality.”
If we want to rely on nuclear energy as long as possible, we need to make the maximum limit of SF and HLW as large as possible. To do so, we must ensure that nuclear power plants maintain quite a high level of safety and that people accept the maximum limit of waste proposed by the government. However, to achieve the latter the Japanese government must rebuild “trust” from society after it was completely destroyed by the Fukushima Nuclear Power Plant Accident on March 11, 2011.
“Trust” is crucially important for governments of all countries to promote nuclear energy because technical safety is not the most difficult problem of nuclear energy. It is also a matter of public acceptance, which can only be created by the “trust” that people have in the government.
There is the last question we should ask. After the long-term storage of SF or HLW for hundreds of years, how could we dispose of it safely? One solution could come with “new technology” developed by the future generation to allow for a safe final disposal such as space disposal or transmutation processing.
Another solution we should continue exploring is “geologic disposal by international collaboration”. Projects to achieve geologic disposal of SF or HLW have been carried out over the past 40 years in countries including the U.S., U.K., France, Germany, Canada, Sweden and Switzerland. However, when looking back at the past four decades, no country has successfully accomplished geologic disposal.
There is one exception. The Onkalo project in Finland is in the experimental stage with very stable geologic formation. I myself was engaged in the U.S.’s Yucca Mountain Project from 1987 to 1988 as a visiting researcher of the Pacific Northwest National Laboratories. The largest reason many countries have been unsuccessful for 40 years is not the problem of “technical feasibility” but that of “public acceptance” in every country.
On the other hand, the issue of the final disposal of SF or HLW is not a problem for each individual country. It is a problem for the global community because during the span of 100,000 years for SF and 30,000 years for HLW, borders of countries and countries themselves could change drastically.
With this in mind, SF and HLW should not be disposed by a country alone but through international collaboration. To do this, we would need to establish “the Second IAEA” (International Atomic Energy Agency), organized especially for the long-term storage and final disposal of SF and HLW.
I suppose the Japanese government has a responsibility to cope with this difficult issue by leading other countries because the most important question for humankind resulting from the Fukushima Nuclear Power Plant Accident is not about “the safety of the nuclear power plant system”. It is about “the safety of the nuclear energy system as a whole”, including the nuclear fuel cycle and the final disposal of spent nuclear fuel and high-level radioactive waste. We mustn’t look at one piece of the nuclear problem. We must look at the entire issue. tj
Images courtesy of the Nuclear Regulatory Commission :
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