Solute transport modelling at the Horonobe URL; Tracer test in the fault zone in mudstone

Murayama, Shota*; Takeda, Masaki ; Ono, Hirokazu ; Tachi, Yukio  

To evaluate mass transport in a fault zone containing multiple fractures, it is necessary to develop an mass transfer model based on the characteristics of the actual fault zone, and to conduct an in-situ tracer test. It is important to obtain information on the transport path and parameters through the tracer test. This paper presents the results of the tracer test conducted in a fault zone in the 350m research drift of Horonobe URL. The spatial distributions of the fractures and transport paths were evaluated based on the observation of the core sample collected after the tracer test and the tracer concentration analysis on the fracture surface. Furthermore, the transport model was applied and validated thorough the interpretation of the test results.