Abstract
Power Reactor and Nuclear Fuel Davelopment Corporation (PNC) has been developing techniques of evaluating groundwater flow in granitic rock. In a link of this purpose, PNC introduced the borehole radar system (RAMAC) which was developed by Swedish Nuclear Fuel and Waste Management Co., because it is critical to investigate the spatial extent and dimensions of fracture zones.
This report describes the results of crosshole measurements which were performed with RAMAC system at the Kamaishi Mine in-situ Experiment Site in the northern part of Honsyu Island, Japan.
The results are summarized as follows:
(1) Spatial extent of some low velocity zones and high velocity zones of electromagnetic waves were delineated.
(2) Almost of the seeping points observed by borehole TV lies in the low velocity zones.
(3) The fracture concentrated zones or fracture zones with groundwater recognized by observing the wall of the gallery, which was dug along the borehole used for crosshole measurements, corresponded to the low velocity zones.
These results indicate that the low velocity zone obtained by the borehole radar measurements corresponds with the fracture concentrated zone or fracture zones with groundwater.
