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Tsushima, Masahito*; Takeda, Masaki; Ono, Hirokazu
JAEA-Data/Code 2018-008, 78 Pages, 2018/10
JAEA-Data-Code-2018-008.pdf:6.73MBJAEA-Data-Code-2018-008(errata).pdf:0.11MB
JAEA-Data-Code-2018-008-appendix(DVD-ROM).zip:263.67MB
Japan Atomic Energy Agency (JAEA) has been conducting "geoscientific study" and "research and development on geological disposal" in the Horonobe Underground Research Laboratory (URL). In-situ tracer migration test for fracture and matrix in the argillaceous rock, called for Wakkanai formation, has been conducted in the Horonobe URL project. This report summarizes data of borehole investigations and tracer migration test for fracture zone.
Takeda, Masaki; Ishii, Eiichi; Ono, Hirokazu; Kawate, Satoshi*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 25(1), p.3 - 14, 2018/06
Fault zones and excavation damaged zones have the potential to act as flow paths, and the characterization of solute transport in such zones in mudstones is important for the safe geological disposal of radioactive waste. However, few in situ tracer migration tests have been conducted on fractures in mudstones. The Japan Atomic Energy Agency has conducted in situ tracer migration experiments using uranine, for fractures in siliceous mudstone of the Wakkanai Formation. 18 experiments were conducted under various conditions An injection flow rate that is slightly higher than the pumping flow rate is ideal for tracer migration experiments involving injection and pumping, as conducted in this study. In situ tracer migration experiments involving injection and pumping conducted in a groundwater environment with dissolved gases allow empirical evaluation of the relationship of the tracer recovery ratio and the groundwater degassing with the injection and pumping flow rate ratio. This evaluation is effective for the design of experimental conditions that account for degassing and ensure high levels of tracer recovery.
Takeda, Masaki; Ono, Hirokazu; Tachi, Yukio; Murayama, Shota*
no journal, ,
This study characterized the solute transport properties of fault zone fractures in a mudstone by applying the modelling approach, which could be addressed heterogeneity in the fault zone fractures. Breakthrough curves (BTCs) derived from dipole tests were simulated with GoldSim code and the model assuming three flow paths individually consisted in the flow and stagnant domain. This modelling approach gave good agreement with the BTCs of uranine and Mo for pulse injection tests. However, there are some gaps of BTCs trend of uranine, Mo and Cs for continuous tests between in situ and simulation results. These gaps can be caused by larger tracer recovery in simulation results than tests results. We will continue to develope the more realistic model and optimal model parameters that can be appropriately treated to uncertainty of transport paths.
