Abstract
In Japan, several kinds of techniques needed for high-level radioactive waste disposal have been researched and developed for the deep underground rock formation which is distributed from several hundreds meter to one thousand meter below the surface. In order to confirm roughly the feasibility on the construction of disposal, as a first step in this study, a fundamental design concept of the underground facilities necessary to dispose of about 37,800 waste forms is discussed, and the depth and scale of the disposal facilities are estimated. Furthermore, an example of the basic layout design for disposal facilities finally is demonstrated under the above discussion.
In the second step, we discussed the more detail design, such as the shape and dimension of tunnels, the types and materials for tunnel timbering, the minimum distance between adjacent tunnels or waste forms and the ventilation and drainage system. Furthermore, we demonstrate an example of the detailed layout design of total disposal facilities under the above discussion.
We also investigated the some construction techniques such as the excavation method, the carrying out method of excavated rocks, the grouting method for rocks around tunnels and the grouting materials and the equipment for ventilation, air-cooling and drainage in tunnels, and then propose roughly a method for construction management based on the present available techniques.
