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Soil from Fukushima radiation decontamination work to be reused in new farmland

Land scheduled to be developed into farmland by reusing soil from radiation decontamination work is seen in the Nagadoro district of the village of Iitate, Fukushima Prefecture, on March 3, 2021. (Mainichi/Nami Takata)

IITATE, Fukushima -- A farmland development project testing the reusability of soil generated from radiation decontamination work after the meltdowns at Fukushima Daiichi Nuclear Power Station has been carried out by the environment ministry in a restricted "difficult-to-return" zone in this northeast Japan village.

    While the area suffered damage from the nuclear disaster following the March 2011 Great East Japan Earthquake and tsunami, residents' feelings on the ongoing tests are conflicted. Although there are plans to send crops yielded on farmland to market in the future, few among the Japanese public know about the scheme to reuse decontaminated soil.

    About 30 kilometers from Tokyo Electric Power Company (TEPCO) Holdings Inc.'s Fukushima Daiichi Nuclear Power Station is the Nagadoro district of the village of Iitate, in Fukushima Prefecture. The district is a "difficult-to-return" zone, which residents have been evacuated from since the onset of high radiation doses in the area from the 2011 Fukushima nuclear disaster.

    There, a white building stands; a recycling plant for removing twigs, rocks, and other foreign objects from decontaminated soil. It's set to start operations in late March. The 34 hectares of land scheduled for reclamation stretch around the facility and to soil on the other side of the road it's on. The land it stands was formerly a rice paddy, and will be made into farmland by filling it with soil removed in decontamination processes. Reclamation work begins in April, and there is estimated to be at least 430,000 metric tons of decontaminated soil set for reuse.

    Since 2018, The Ministry of the Environment has been doing tests toward farmland development in the Nagadoro district, the only area in Japan where they take place. In their investigations, vegetables and flowers are grown in mounds of soil made of decontaminated dirt with a radioactive cesium concentration of 5,000 becquerels per kilogram or less -- the standard limit said by the environment ministry to have no repercussions for agricultural workers -- and covered in a 50 centimeter-layer of separate dirt.

    Cesium concentration levels for corn, turnips and cherry tomatoes harvested in 2020 were between 0.1 and 2.3 becquerels per kilogram, below the 100 becquerels per kilogram maximum standard for shippable produce as specified by the Ministry of Health, Labor and Welfare.

    Since 2020, the environment ministry has also tried cultivating crops in soil without the extra dirt layer. Although the produce gets disposed of for now, the ministry plans to give them to the village once the farmland is completed, and have the goods shipped to market after commercial farming resumes. When exactly farming will resume remains undecided.

    Today, the Nagadoro district is still uninhabitable due to radiation. Why then did it accept the reclamation project using decontaminated soil? Yoshitomo Shigihara, 70, former head of Nagadoro district, emphasized it was a tough decision, saying, "It wasn't like the district gave its wholehearted support for the plan."

    Evacuation orders were lifted from Iitate, excluding the Nagadoro area, in spring 2017. Concern has spread among locals regarding the left-behind district. The national government has set up Specified Reconstruction and Revitalization Bases in difficult-to-return zones, and is carrying out intensive decontamination work to make the area habitable again. It aims to lift evacuation orders from the district in spring 2023, but then-village head Norio Kanno, 74, explained that "only a 'mini reconstruction base' of around 2 to 3 hectares can be made."

    According to Kanno, a national government employee who was in the village around 2017 first proposed the reuse of decontaminated soil. A majority of residents were in favor of the plan in hopes the decontamination area may be expanded if the project were accepted. The village and the environment ministry agreed to the tests in November 2017. As a result, the Nagadoro district reconstruction base was expanded to 1.9 square kilometers of the district's total 10.8 square km area.

    Before the 2011 disasters, the Nagadoro area was a mountain community of about 280 people. Making a living from farming alone was hard, and many farmers had multiple occupations. Shigihara, who owned cattle, said, "We were told the land would be left barren and untreated by decontamination work. If this mean it'll be restored, I have no choice (but to accept the tests)."

    Although Kanno said, "If the district didn't accept the soil reuse project, the reconstruction base would have been left as it was," the Ministry of the Environment responded to a Mainichi Shimbun inquiry by saying the district's approval of the farmland project and the decontamination range expansion were "unrelated." The nature of these causal relations remains unknown.

    (Japanese original by Nami Takata, Yokohama Bureau)

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