低レベル放射性廃棄物の余裕深度処分に関する検討状況

抄録

Considering the situation of energy demand in Japan, nuclear power generation might be growing up from now on.
Nuclear power plants, however, produce radioactive wastes. The wastes must be disposed safely for long term. In this paper, the present plans of the waste disposal of several radioactive levels in Japan are summarized.
First of all, the radioactive wastes are categorized into low and high levels in accordance of their radioactivities.Since the low level wastes also have several classes depending on their activities, we have to select a different disposal design. Of these disposal designs, the projects for low levels are explained in detail.
Moreover, it is noteworthy to dispose the relatively high low-level radioactive wastes. Its disposal design is called as “subsurface disposal” and its facilities are being planned to be constructed more deeply than the facilities for the other low level wastes. A fundamental concept for the subsurface disposal design is discussed on the view of assuring safety against the radioactive pollution.
Scientific knowledge and engineering technologies for the study on the subsurface disposal design are discussed. In particular, the following items; the 3D seismic survey for searching faults, 3D groundwater flow analysis by considering long-term changes in topography and climate,and evaluation of the changes in geochemical conditions and rock characteristics around a spacious cavern.