Japan Institute for National Fundamentals

Speaking out

Tadashi Narabayashi

【#221】High-level Radioactive Waste Can Be Disposed Safely

Tadashi Narabayashi / 2013.11.21 (Thu)

November 18, 2013

      Since a brief visit to the Onkalo (a Finnish word meaning cave) underground facility for disposal of high-level radioactive waste in Olkiluoto, Finland, former Prime Minister Junichiro Koizumi has argued that Japan should withdraw from nuclear power generation because no site has been fixed in Japan for final disposal of such radioactive waste. His argument is wrong.

Vitrification for underground burial
      High-level radioactive waste will be melted into hot, liquid glass and put into stainless canisters in the form of vitrified waste. The vitrified waste will be put in “overpack” thick iron or copper containers for underground burial. The containers will be placed into holes dug in bedrock. Water-shielding clay will be filled into holes to safeguard against rare radiation leaks.
      On exhibition at the Shimane Prefectural Museum of Ancient Izumo neighboring Izumo Grand Shrine in Western Japan are bronze vessels and arms that were found at nearby remains left from the Yayoi Era between the second century BC and the second century AD. Ornamental patterns on their surface are still clear, indicating that metals can be stored without corroding underground for more than 2,000 years.
      Radiation from high-level radioactive waste is very strong initially and will diminish to one-thousandth in 40 years. Such waste will be stored in a building (called an interim storage facility) for the initial 40 years. Japan already has such facility in Aomori Prefecture, about 700 kilometers north of Tokyo. At this facility, only air is used to cool radioactive waste. Air naturally comes into the facility and warmer air goes out of it. No electricity is necessary. Over the 40 years, we may carry out discussions on a final burial site. Even if the site fails to be determined, the storage in the facility can be extended. Radiation will diminish to one-10,000th in 150 years, to one-100,000th in 800 years and to one-millionth in 3,000 years.

Carry out discussions to get people’s understanding
      Radiation from high-level radioactive waste may take as long as 10,000 to 20,000 years to diminish to the same level as from uranium ore. But to store such waste in a building for 800 years is not too long for Japan, which has a nation’s history of 2,000 years. Storage fees can be collected if necessary. Basically, high-level radioactive waste should be stored under management in a building for 40 or 150 years. While watching overseas developments, the government may carry out discussions and get the people’s understanding about nuclear safety. It does not have to hurry up in finding a final radioactive waste disposal site. If no stable bedrock is found underground, a stone building like an Egyptian pyramid may be constructed for storing radioactive waste.
      Has former Prime Minister Koizumi run mad? His frivolous argument battered his brilliant work record. In response, the ruling Liberal Democratic Party's Secretary General Shigeru Ishiba has begun to call on the government to take leadership in deciding on the final nuclear waste disposal site. But such hasty approach may come under fire among citizens as hoped by former Prime Minister Koizumi. Only several tunnels of the size for the Seikan underground tunnel between Hokkaido and Aomori Prefectures will be required for burial of all spent nuclear fuels from Japan's nuclear plants after their reprocessing. None has to make a lot of noise about the final nuclear waste disposal site.

Tadashi Narabayashi is Director, Japan Institute for National Fundamentals, and Professor at the Hokkaido University Graduate School of Engineering.