Geosciences research: geoscientific studies at the Chubu works

Geoscientific studies at the Chubu Works have been carried out in the four areas as below. (a) Rock Properties: Influence of the excavation of a shaft and a drift on the mechanical and hydraulic properties of the surrounding rock mass. (b) Groundwater Flow: Hydrogeological models of the Tono area have been developed based upon relevant data from the literature and the field. A three-dimensional analysis of the groundwater flow was conducted using these models. Validation and further improvement of these models are underway. (c) Hydrogeochemistry: In-situ measurements and laboratory analyses on the geochemical properties of the deep groundwater have been continued. Geochemical evolution of the groundwater have been studied from a viewpoint of the rock-water interaction. (d) Isotope Chemistry of Groundwater: Migration and fixation of natural uranium-series nuclides in the geological environment have been studied based on the observation of the occurrence of uranium-series nuclides in the Tono uranium deposit as well as on the laboratory experiments. (author)