TOKYO -- Four Japanese power companies plan to decommission a total of five aging nuclear reactors soon. But they have yet to find a home for the radioactive waste that will result -- not only spent nuclear fuel but also debris from the dismantled reactors.
Japan Atomic Power announced on March 17 that it plans to decommission its Tsuruga No. 1 reactor in Tsuruga, Fukui Prefecture, on April 27. Kansai Electric Power unveiled a similar plan for its Mihama No. 1 and No. 2 reactors in Mihama, Fukui Prefecture, and Kyushu Electric Power announced its intention to close Genkai No. 1 reactor in Genkai, Saga Prefecture.
On March 18, Chugoku Electric Power President Tomohide Karita officially informed the mayor of Matsue that the company is planning to decommission its Shimane No. 1 reactor, located in the Shimane Prefecture city. In response, the mayor asked the utility to remove the nuclear waste from the site as soon as possible after decommissioning, as the continued presence of such hazardous material would greatly upset citizens.
Reprocessing nuclear fuel produces highly radioactive waste that contains substances so toxic that even 20 seconds' exposure to them can be fatal for a human being. Such waste needs to be sequestered 300 meters underground for tens of thousands of years.
Decommissioning a nuclear reactor also generates around 4,000 tons of debris, including concrete, metal and other building materials. And unlike with an ordinary factory, some of it is contaminated with radioactive material. Such debris may be less radioactive than nuclear fuel, but finding disposal sites for it is still next to impossible.
An official at Kansai Electric Power said radioactive waste cannot be kept on-site at a nuclear power plant even on a tentative basis without obtaining the consent of the local community.
An even bigger problem is how to dispose of the core internal structures of nuclear reactors, which contain substances that will release radiation for generations to come. Disposing of these structures requires burying them more than 50 meters deep.
Matsue and other communities hosting soon-to-be-decommissioned reactors naturally want any waste to be removed as soon as possible. The decommissioning of all five reactors will result in an estimated 20,000 tons of radioactive material.
Caught off guard
The failure to secure disposal sites for nuclear waste seems an obvious oversight on the part of utility companies. The Japan Atomic Energy Agency's Hiroshi Rindo, an expert on decommissioning procedures in Europe and the U.S., said it is customary for nuclear reactor operators abroad to prepare repositories or dumping sites for radioactive waste in advance.
One reason for Japanese companies' failure on this front is that they are having to decommission some reactors earlier than planned. In January 2011, Makoto Yagi, president of Kansai Electric Power, told government officials of Fukui Prefecture that the company intended to operate the No. 2 reactor in Mihama as long as possible, potentially more than 40 years. At that time, the company had already decided to keep the No. 1 reactor working for up to half a century, if possible.
The plan ran into trouble only two months later, however, when disaster struck Tokyo Electric Power's Fukushima Daiichi power plant in Fukushima Prefecture. The accident led to strengthened national regulations that cap reactors' operational life span at 40 years, in principle. In addition, the implementation of stricter and more expensive safety measures has made the continued operation of aging reactors unfeasible.
Because Kansai Electric Power will have to shut down the No. 1 and No. 2 reactors in Mihama earlier than planned, the company has had less time to find a repository for its radioactive waste.
It is still some time before dismantling work begins on the Shimane No. 1 and other reactors to be decommissioned, but with Japan's nuclear plants slated to resume operating this summer, utilities have no time to lose in finding a final home for their waste.