Okuma, Fukushima Pref. ¨C On the surface, everything seems to be under control at the expansive site storing radioactive soil collected from across Fukushima Prefecture in the aftermath of the 2011 core meltdowns at the Fukushima No. 1 nuclear power plant.

Since 2015, the Interim Storage Facility, which straddles the towns of Okuma and Futaba and overlooks the crippled plant, has safely processed massive amounts of radioactive soil ¡ª enough to fill 11 Tokyo Domes ¡ª in an area nearly five times the size of New York¡¯s Central Park. The soil was collected during decontamination procedures in Fukushima¡¯s cities, towns and villages that were polluted by the disaster.

Here, black plastic bags full of contaminated soil are put on conveyor belts and unpacked. The contents are sifted through to remove plastic, leaves, twigs and other nonsoil waste. Then the soil is taken to dump zones, where it¡¯s buried in 15-meter-deep pits with protective sheeting and a drainage pipe at the bottom so that radioactive cesium won¡¯t leak into the ground. Finally, the soil is covered with noncontaminated soil and topped with a lawn. Areas where the work has been completed look like soccer fields.

The level of radiation here is about 0.2 microsieverts per hour (uSv/h), explained Hiroshi Hattori, an official at the Environment Ministry¡¯s local office, during a recent tour of the areas where the polluted soil is buried. The radiation level there is harmless to humans, though higher than an average of 0.04 uSv/h elsewhere in Japan.

¡°It¡¯s higher not because of the soil, but because of surrounding forests (which have not been decontaminated).¡±

The problem is that, as smooth and orderly as its operations are, the site is only a temporary home for the radioactive soil. Nobody knows where this massive pile of dirt will eventually end up. All that is certain is that the central government has pledged to ¡ª and is legally obliged to ¡ª move all of the soil out of Fukushima Prefecture by 2045.

This unresolved soil issue ¡ª along with the lingering dispute over the planned ocean release of tritium-laced wastewater from Fukushima No. 1 ¡ª is a sour reminder of the enormous toll the nuclear disaster in Fukushima has inflicted on the country and beyond.

Opposition from residents

The soil is a product of years of state-funded measures to bring radiation levels down in communities affected by the disaster. The government drew up a ¡°decontamination road map¡± soon after the accident, in the hopes of a speedy return of residents to their hometowns.

The desire to avoid moving the massive amount of soil again ¡ª and to make it easier to find a final destination for it ¡ª has also led the...