放射性廃棄物 (2)

[VII-137] In-Site Test of a Bentonite Pellet Backfilling Method for Prefabricated Engineered Barrier System Module

*森 拓雄¹、丹生屋 純夫¹、小林 正人²、西村 政展²、中山 雅³ (1. 株式会社大林組、2. 公益財団法人原子力環境整備促進・資金管理センター、3. 国立研究開発法人日本原子力研究開発機構)

Keywords:Radioactive waste depository, Bentonite, Engineered Barrier, Dry density

Prefabricated Engineered barrier system Module (PEM) is one of option for Radioactive waste emplacement. Narrow gap between Tunnel and PEM must be backfilled with Bentonite, to prevent water permeability. Authors developed Bentonite Pellet Backfilling Method for the narrow gap. In-site test was executed at Horonobe URL -350m. Bentonite Pellet was backfilled two gaps (Minimum width: 110 mm) between an actual size PEM and the Tunnel. A 1.37 Mg/m3 backfill dry density is achieved. It was proofed that the Bentonite Pellet Backfilling Method is averrable for the Radioactive waste emplacement.