クリプトン回収技術開発施設の窒素代替設備追加及び液体窒素貯槽撤去による維持管理の合理化

Rationalization of maintenance at the Krypton Recovery Development Facility by adding nitrogen replacement equipment and removing liquid nitrogen storage tank

古内 雄太; 岡田 純平; 木村 典道*; 渡邉 一樹 ; 林 慶諭*; 平山 悠介*; 田代 慶行*; 内田 直樹

Furuuchi, Yuta; Okada, Jumpei; Kimura, Norimichi*; Watanabe, Kazuki; Hayashi, Yoshitsugu*; Hirayama, Yusuke*; Tashiro, Yoshiyuki*; Uchida, Naoki

クリプトン回収技術開発施設の屋外の液体窒素設備から供給される窒素ガスは、施設内の負圧の維持に用いる圧縮空気の供給停止時のバックアップとして使用してきたが、液体窒素貯槽は津波漂流物となり得るため早期の撤去が必要であり、その代替策(合理化)を検討した。最小限の追加設備と長期間の運用を踏まえ、既設の空気圧縮機に自動切換機能を追加後、液体窒素設備を廃止(貯槽を撤去)し、施設の保全管理の効率化を図った。

At Krypton Recovery Development Facility in Tokai Reprocessing Plant (TRP), the nitrogen gas, which was supplied from the liquid nitrogen tank, was used instead of compressed air to manage the enclosure function of the facility during the compressor was broken. It was necessary to remove the liquid nitrogen tank possible because it had the possibility of being tsunami debris which affect significant impact on the other TRP facility. Before the tank removal, the automatic switching function was attached to the air compressors as nitrogen replacement equipment. This function switches the starting and stopping the compressors, opening and closing valves after detection of equipment failure. When attaching this function, additional equipment was minimized by utilizing existing equipment. Then, the liquid nitrogen tank was dismantled after transporting outside TRP. These works eliminated the cost of purchasing liquid nitrogen and inspections of the equipment.