Experience of clean-up activities and feedback to future D&D projects; Japan Power Demonstration Reactor decommissioning project

クリーンアップ作業の経験と将来の除染と廃止措置計画への反映; JPDR廃止措置プロジェクト

柳原 敏; 立花 光夫; 島田 太郎 ; 助川 武則; 白石 邦生

Yanagihara, Satoshi; Tachibana, Mitsuo; Shimada, Taro; Sukegawa, Takenori; Shiraishi, Kunio

廃棄物管理や規制に関する観点から、JPDR廃止措置プロジェクトで実施された建家構造物の解体と管理区域の解除に関するクリーンアップ作業を評価するとともに、将来の廃止措置に反映すべき課題をまとめた。特に、初めて適用した、施設の運転履歴の調査、建家表面の汚染状況の調査、除染と確認測定等の手順を整理するとともに、将来の廃止措置で必要となる、管理区域解除の手順や放射能測定等のための知見をまとめた。これらは、将来、廃止措置プロジェクトの安全で合理的な実施に必要となる規制の検討や標準化に有効と考えられる。

In the Japan Power Demonstration Reactor (JPDR) decommissioning project, the procedure for clean-up activities was specially studied for harmonization with radioactive waste treatment policy in Japan; it consisted of several components such as survey of the facility operational history, radiological characterization of building surfaces, decontamination and final survey of radioactivities. After confirming that there was no significant radioactivity in the facilities in the final step of the procedure, buildings were demolished in consideration of treatment of wastes as non-radioactive materials. The JPDR decommissioning project was completed by March 1996 with no serious problems, which showed that the procedure was rational, and that the experiences are useful for planning of future decommissioning activities. The dismantling and clean-up activities were reviewed, and the experiences are excepted to contribute to establishing standard and regulatory systems on decommissioning nuclear facilities.