Measurement plan and observational construction program on shaft excavation at the Horonobe Underground Research Laboratory project


Morioka,-Hiroshi; Yamaguchi,-Takehiro; Funaki,-Hironori (Japan Atomic Energy Agency, Geological Isolation Research and Development Directorate, Horonobe Underground Research Unit, Horonobe, Hokkaido (Japan)); Orukawa,-Go (Japan Atomic Energy Agency, Horonobe Underground Research Center, Horonobe, Hokkaido (Japan)Japan Atomic Energy Agency (JAEA) is carrying out phased investigation in Horonobe, Hokkaido. This investigation named as 'Horonobe Underground Research Laboratory Project' (Horonobe URL Project) targeting sedimentary formations, is intended to confirm the reliability of technologies on geological disposal of High-Level Radioactive Waste (HLW) by applying them into in-situ geological environment. On the Horonobe URL Project, 'Phase 1: Surface-based investigations' was finished in 2005FY and construction of the underground facility was started since then. Now, 'Phase 2: Construction phase' (investigations during construction of the underground facilities) is on-going. In Phase 1 of the Horonobe URL Project, investigations were carried out from the surface and modeling of geological environment was carried out. Prediction of influence to the geological environment caused by excavating (in Phase 2) of underground facilities was also carried out. In Phase 2, in-situ detailed (geological, hydrogeological, hydrochemical and rock mechanical) investigations and validation of prediction results in Phase 1 are carried out. In 'Phase 3: Operation phase' (investigations in the underground facilities), detail investigations of geological environmental feature around the shafts will be carried out. In-situ experiments for research and development on geological disposal will be also carried out. On the 'Development of engineering techniques for use in the deep underground environment' in Phase 1, based on the various type of data acquired on investigations from the surface, basic design of underground facilities in advance was carried out. This report summarizes the measurement plan during construction of the underground facility based on the design in advance and the observational construction program for feedback measurements data into design and construction on subsequent steps. This report also describes about design and construction management program for contractor of underground facilities. The measurement plan described in this document is applied to measurements in the underground facilities for validation of the geological environmental model. Then, it will be verified the validity by application into actual construction and will be systematized with modification when necessary.