ABSTRACT
Hokuriku Electric Power Co. is currently constructing Shika Nuclear Power Plant Unit No. 2 in order to start commercial operation in March 2006. The intake and discharge water will be via undersea tunnel, as well as Unit No. 1, in order to minimize environmental impact. Various techniques such as shield tunneling, NATM and semi-shield method was adapted to excavate large diameter rock tunnel under high water pressure. This article deals with such various techniques and achievements.
