Volume Reduction System by Soil Classifying Soil-washing System and Problems to Be Solved押野嘉雄*、除染・廃棄物技術協議会浄化土壌ワーキンググル¹除染・廃棄物技術協議会前代表幹事(鹿島建設株式会社: 〒107-8348東京都港区赤坂6-5-11) ²除染・廃棄物技術協議会(事務局:株式会社三菱総合研究所: 〒100-8141東京都千代田区永田町2-10-3) Yoshio OSHINO 1*,  Purified Soil Working Group in Technical Advisory Council on Remediation and Waste Management² 1 Previous Chairman of Technical Advisory Council on Remediation and Waste Management (Kajima corporation:5-11, Akasaka 6-Choume, Minato-ku, Tokyo 107-8348, Japan) ²Technical Advisory Council on Remediation and Waste Management (Secretariat: Mitsubishi Research Institute, Inc. : 10-3, Nagata-cho 2-chome, Chiyoda- ku, Tokyo 100-8141, Japan)
Summary
Radioactive contamination of ground surfaces, buildings and forests in a broad area was caused by the accident at the Fukushima Daiichi Nuclear Power Plant in Japan. The national government and municipalities have still been carrying out the decontamination works for livelihood areas after five years from the accident. The government estimated that the amounts of soils and wastes removed by the decontamination works would be about 28,000,000 cubic meters maximum including 20,000,000 cubic meters maximum of soils. The removed soils will be stored in "Interim Storage Facility" then will be finally disposed outside of Fukushima prefecture within 30 years. On the other hand, shortage of the soils as materials needed for the revitalization in Fukushima prefecture is expected. Technical Advisory Council on Remediation and Waste Management, which consists of about 90 companies, started a working group to investigate solutions to these problems. The working group focused on the investigation of the possibility to recycle the soils by washing and classification to use them as the materials for civil engineering works, and to reduce the volume of the interim storage. In the first part of this report, we have evaluated the applicability of various technologies for purification and volume reduction of the removed soils, and have researched usages, required quantities and specifications of the recycled soils. In the second part, we have made trial calculations of the volume reduction effects and costs using the washing and classification system. The calculated results showed the possibilities of reducing the storage capacity of the interim storage facility, as well as the construction and the operation costs by recycling the removed soils with the washing and classification system inside the interim storage facility. At the end of this report, we proposed problems to be solved in order to adopt the washing and classification system. Key Words: Radioactive contamination in the environment, Interim storage facility, Recycle, Soil-washing system
和文要約
東京電力福島第一原子力発電所の事故では、広範囲にわたる地表、建物、森林などに放射性物質による汚染が発生した。国や市町村による本格除染は生活圏を中心に事故から5年になる今も行われている。政府の詠算では、除染による除去土壌や廃棄物の量は、全体で最大約2,800万m³、除去土壌だけで最大約2,000万m³と推測されている。除去土壌は中間貯蔵施設で貯蔵され、 30年以内に県外で最終処分される。一方で、福島県の復興のために必要な資材としての土壌が不足することが予測されている。約90社の企業からなる除染・廃棄物技術協議会は、これら問題の解決策を検討するためにワーキンググループを設置し、土壌を分級・洗浄し、これを土木資材として活用し、中間貯蔵施設の容量を減らす可能性の検討を行った。本報告の前半では、各種の土壤浄化域容技術の適用性を評価するとともに、再生利用の用途、必要量、仕様について調査を行った。後半は、分級选浄システム適用時の減容効果と費用を試算した。この結果、中間貯蔵施設内において土壌を再生利用することにより、中間貯蔵施設の必要容量を減らし、建設及び運用コストも減らすことができることが明らかとなった。最後に、分級洗浄システムを適用するにあたり、今後の検討が必要な課題を示した。