This article presents findings from an extensive experimental program conducted by the French Agency for the Management of Radioactive Waste(ANDRA)at its Underground Research Laboratory.The focus of the study is the N...This article presents findings from an extensive experimental program conducted by the French Agency for the Management of Radioactive Waste(ANDRA)at its Underground Research Laboratory.The focus of the study is the NSC(Noyau de SCellement)experiment,designed to assess the performance of a sealing core composed of a mixture of 40%bentonite and 60%sand.The objective is to evaluate in situ hydraulic permeability,swelling behavior,and gas performance of the seal,which are essential components for the safe disposal of Intermediate-Level(IL)and High-Level Radioactive Waste(HLW)in deep geological repositories.The experimental setup,construction details of the NSC experiment,and the timeline of the project,from excavation,construction of the seal,and artificial hydration to hydraulic permeability tests,are comprehensively described.Andra has acquired valuable expertise in constructing an engineered barrier system,encompassing concrete plugs,and efficiently assembling a 5-m-long seal.Over the past decade,a controlled water injection process has been employed to hydrate the seal.The operational efficiency of sensors has been evaluated,with pore pressure sensors exhibiting moderate performance.In contrast,others,including total pressure,capacitive humidity,psychrometric humidity,and saturation sensors,demonstrate excellent performance up to their operational limits.The high-quality data obtained from this experiment will facilitate the modeling of the resaturation and hydraulic-gas performance of the seal.展开更多
China has achieved a major engineering milestone in the construction of the Beishan Underground Research Laboratory(URL)for geological disposal of high-level radioactive waste(HLW).On December 26,2025,the project team...China has achieved a major engineering milestone in the construction of the Beishan Underground Research Laboratory(URL)for geological disposal of high-level radioactive waste(HLW).On December 26,2025,the project team successfully completed the excavation of the world's first deep,continuous small-radius,steep spiral ramp by a tunnel boring machine(TBM)named Beishan No.1,which marked the completion of the underground main structure of Beishan URL.展开更多
摘要This article presents findings from an extensive experimental program conducted by the French Agency for the Management of Radioactive Waste(ANDRA)at its Underground Research Laboratory.The focus of the study is the NSC(Noyau de SCellement)experiment,designed to assess the performance of a sealing core composed of a mixture of 40%bentonite and 60%sand.The objective is to evaluate in situ hydraulic permeability,swelling behavior,and gas performance of the seal,which are essential components for the safe disposal of Intermediate-Level(IL)and High-Level Radioactive Waste(HLW)in deep geological repositories.The experimental setup,construction details of the NSC experiment,and the timeline of the project,from excavation,construction of the seal,and artificial hydration to hydraulic permeability tests,are comprehensively described.Andra has acquired valuable expertise in constructing an engineered barrier system,encompassing concrete plugs,and efficiently assembling a 5-m-long seal.Over the past decade,a controlled water injection process has been employed to hydrate the seal.The operational efficiency of sensors has been evaluated,with pore pressure sensors exhibiting moderate performance.In contrast,others,including total pressure,capacitive humidity,psychrometric humidity,and saturation sensors,demonstrate excellent performance up to their operational limits.The high-quality data obtained from this experiment will facilitate the modeling of the resaturation and hydraulic-gas performance of the seal.
摘要China has achieved a major engineering milestone in the construction of the Beishan Underground Research Laboratory(URL)for geological disposal of high-level radioactive waste(HLW).On December 26,2025,the project team successfully completed the excavation of the world's first deep,continuous small-radius,steep spiral ramp by a tunnel boring machine(TBM)named Beishan No.1,which marked the completion of the underground main structure of Beishan URL.