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radioactive material
放射性物質の管理は厳重だ。
Radioactive materials are managed under strict controls.
放射性物質が漏れた事故が報告された。
An accident involving a leak of radioactive material was reported.
放射性物質を扱う施設では被曝防止の対策が必須だ。
Radiation protection measures are mandatory at facilities handling radioactive materials.