Modelling heterogeneous hydration behaviour of bentonite by a FracMan-Thames coupling method for the Bentonite Rock Interaction Experiment (BRIE) at sp HRL

澤田 淳; 坂本 和彦*; 綿引 孝宜*; 今井 久*

SKB P-17-06, 154 Pages, 2023/08

An aim of Task 8, which was 8th modeling task of the SKB Task Forces on Groundwater Flow and Transport of Solutes, was to improve the knowledge of the bedrock-bentonite interface with regard to groundwater flow, mainly based on a set of data obtained by Bentonite Rock Interaction Experiment (BRIE) at sp. JAEA had developed an approach to Task 8 assuming that the discrete features dominate the delivery of groundwater to the bentonite columns emplaced into the vertically drilled boreholes from TASO tunnel floor, resulting in heterogeneous bentonite wetting behavior. This assumption was implemented as a FracMan Discrete Fracture Network (DFN) model for groundwater flow. Due to the assumption, no permeable rock matrix was implemented. The variability and uncertainty of this stochastic "HydroDFN" model was constrained by conditioning the model to match measured fracture location and orientation, and specific capacity (transmissivity) data observed at five probe boreholes. Groundwater from the HydroDFN being delivered to the bentonite columns, was modeled using Thames code with implementing a specific feature at the interface between the fractured rock mass and the bentonite. This modeling approach and the assumption of fracture dominated bentonite wetting appears to be able to provide a reasonable approximation to the observed heterogeneous bentonite wetting behavior of BRIE. We would suggest that a systematic investigation at pilot holes, including both geological mapping of the fractures and also testing of the hydraulic properties, might be required to get more practical prediction of heterogeneous wetting behavior in bentonite, as observed in BRIE.

New method for model coupling using Stampi; Application to the coupling of Atmosphere Model (MM5) and Land-Surface Model (SOLVEG)

永井 晴康

JAERI-Data/Code 2003-021, 36 Pages, 2003/12

JAERI-Data-Code-2003-021.pdf:1.73MB

地表付近の熱,水及び物質交換の研究に適用する目的で、大気-陸面結合モデルの開発を行っており、並列計算通信ライブラリMPI(Message Passing Interface)を用いたモデル結合手法を考案した。大気モデルにはペンシルバニア州立大学と米国大気研究センターが開発したメソスケール非静力大気モデル(PSU/NCAR-MM5)を、陸面モデルには原研で開発した接地層大気,土壌及び植生を含む詳細なモデル(SOLVEG)を用いた。また、MPIとしては、原研で開発した異機種並列計算機間通信ライブラリ(Stampi)を用いた。各モデルの独立した平行計算において、それぞれの計算結果をMPIにより交換し合うことにより結合を行う。