Planned facilities in the MIU Project consist of facilities on the ground surface, shafts and research drifts (Fig.2.4). According to the construction program of facilities decided by 1999 FY, following shafts and drifts are planned.

A main shaft for the access to ca.1,000m in depth
A ventilation shaft
Two groups of research drifts at different depths (Main stage and Sub stage)
A spiral ramp to avoid the Tsukiyoshi Fault expected at ca.950m in depth near the main shaft

According to the previous investigations, few fractures occur in the depth between 400m and 700m, whereas there are many fractures at the depth exceeding 800m. Thus, the above-mentioned two groups of research drifts are planned to be excavated in the depths of ca.500m and ca.1,000m to study two kinds of rock masses. They are named as the Sub stage and the Main stage, respectively.

The facilities on the ground surface consist of not only facilities for a research/ administration facility, a sample storage, an equipment maintenance facility but also a well-head facility, a muck deposit and a waste water treatment facility.

The optimization of facilities design will be carried out as the data are accumulated in the Phase I, and as Phase II goes into mode detail.