Around 20,000 tons of designated waste is being stored outside Fukushima Prefecture, but disposal has proven difficult.
Local authorities have strongly opposed the central government’s policy that designated waste should be consolidated into one place in each of the local authorities’ areas and stored there for a long period.
Thus, designated waste has been stored in different locations, including agricultural fields or local authorities’ facilities.
Some have voiced concern, however, that the designated waste could leak outside in the event of a disaster.
The 2011 nuclear accident released radioactive substances into the air. The wind then transported the substances to other areas.
The government later decided that contaminated waste, such as incinerated ash or rice straw, were designated waste if their radioactivity concentration exceeded 8,000 becquerels per kilogram.
After the 2011 accident, the Environment Ministry set the threshold of 8,000 becquerels per kilogram as the level at which “the safety of workers can be guaranteed in the typical tasks of disposing of radioactive waste.”
The government decided that it is responsible for disposing of the designated waste and has set a basic policy that it will fund and build final disposal facilities.
Its basic policy also says disposing of designated waste will be carried out in the prefectures where it was generated.
Around 407,000 tons of designated waste were stored in 10 prefectures, including Tokyo, as of the end of September 2022, according to the Environment Ministry.
Nine prefectures, including Tokyo, are storing around 25,000 tons of it.
Of those, five prefectures–Miyagi, Ibaraki, Tochigi, Gunma and Chiba–have around 22,000 tons.
For these five prefectures, the ministry announced a plan to consolidate and dispose of the designated waste at final disposal facilities, one of which would be built in each of the five prefectures.
By 2015, the ministry chose candidate sites for the final disposal facilities in Miyagi, Ibaraki, Tochigi and Chiba.
However, it faced fierce opposition from these areas because of concerns about reputational damage.
The ministry was forced to withdraw its selection of the candidate site in Ibaraki. The task of consolidating designated waste is not making progress in the other prefectures either.
Meanwhile, the designated waste’s radioactivity levels have gradually lowered.
The ministry estimated the radioactivity concentration of between 10,333 tons and 11,633 tons of the designated waste exceeded 8,000 becquerels per kilogram in the five prefectures as of fiscal 2016.
This means the radioactivity concentration of more than 40 percent of the designated waste in the five prefectures was estimated to not exceed 8,000 becquerels per kilogram.
Such waste can be disposed of together with ordinary waste if the ministry decides to lift the designation after discussions with local authorities.
However, local authorities are not eager to lift the designation because they will then be responsible for disposing of such waste.
As of the end of September, the ministry had only lifted the designation of around 2,786 tons in the five prefectures.
Meanwhile, in Fukushima Prefecture, where most of the designated waste is stored, such waste with a radioactivity concentration of 100,000 becquerels per kilogram or under has been transported to a final disposal facility in Tomioka.
(This article was written by Wataru Netsu and Hideki Motoyama.)