In order to further expand the geoscientific researches that has been carried out in and its vicinity of the Tono Mine, JNC decides to forward the MIU Project aiming at granite, one of the crystalline rocks widely distributed in Japan, as the main study object in the Shobasama site in Akeyo-cho, Mizunami City, Gifu Prefecture. By reiterating a series of approaches consisting of survey, prediction and verification of the underground geological environment, the project is aimed at confirming the validity of the methodologies of investigations and assessment for the geological environment with a high precision and efficiency. The whole project is divided into the following three Phases and extends over 20 years⁸⁾ (Fig.2.1).

Phase I : Surface-based investigations
The geological environment deep underground as well as the effects of shaft excavation in the Phase II on the geological environment are predicted by the surface-based investigations.

Phase II : Construction
The validity of the prediction of the geological environment and the effects of shaft excavation on the geological environment in the Phase I are verified. Besides, the geological environment expected to occur in the research drifts excavated in the Phase III are predicted.

Phase III : Operations
Detailed data on the geological environment in the drifts are obtained. Besides, the validity of the prediction of the geological environment in the Phase II is verified. Also, the usefulness of engineering techniques deep underground is verified.