Japan's Environment Ministry is studying the possibility of using some screened soil cleared from Fukushima Prefecture after the 2011 nuclear power plant accident in public works projects.
The Japanese government says, within the next 30 years, it plans to dispose of some 22 million cubic meters of soil and other waste that will be removed from the prefecture as part of the decontamination effort.
To make the job easier, the Ministry hopes to use soil with acceptable levels of radioactive material to build roads, embankments and parks.
The ministry began testing the feasibility of such projects last month at a temporary storage site in Minami Soma, Fukushima Prefecture. The process was shown to the media on Wednesday.
The experiment involves sifting the soil to remove rocks, leaves and branches, then entering it into a machine that measures the level of radioactive substances. The soil is then piled into mounds.
Ministry officials will monitor radiation levels in the air and groundwater around the mounds.
They plan to draw up guidelines for local governments and construction workers by the end of March 2019.
The ministry says it aims to use soil with up to 6,000 becquerels per kilogram of radioactive substances in roads and embankments, and up to 4,000 becquerels in parks.
But residents in Minami Soma have requested that for the experiment, the Ministry only use soil with up to 3,000 becquerels per kilogram.
As a result, the officials are unable to test whether soil with higher levels of contamination is safe for recycling.
The project also raises questions about the long-term monitoring of public works built with contaminated soil, and how the Ministry will win the support of people who live nearby.