Representation of Fracture Zone Interpretation Uncertainty in 3D Geological Models of the Mizunami Underground Research Laboratory, Japan

2003 ◽  
Vol 807 ◽  
Author(s):  
Matthew J. White ◽  
Hiromitsu Saegus
Keyword(s):  
Fracture Zone ◽  
Research Laboratory ◽  
3D Structure ◽  
Geological Structure ◽  
Granitic Rocks ◽  
Geological Environment ◽  
Fracture Zones ◽  
Geological Models ◽  
Hydrogeological Properties ◽  
Underground Research Laboratory

ABSTRACTThe Japan Nuclear Cycle Development Institute (JNC) is undertaking research into the deep geological environment in Japan in the Tono area of Japan. In the Mizunami Underground Research Laboratory (MIU) Project, located in the Tono area, JNC is carrying out surface-based investigations and will excavate an Underground Research Laboratory (URL) in order to establish comprehensive techniques for investigating and characterising the geological environment. The MIU Project focuses on the investigation of the granitic rocks of the Toki Granite. The geological structure and hydrogeological properties of the Toki Granite are closely affected by the regional fracture zones and faults. The interpretation of these features is undertaken in 3D and directly linked into 3D hydrogeological models. Significant uncertainty exists in the 3D interpretation of the fracture zones, and geologists must make several assumptions regarding the 3D structure in order to develop the 3D interpretation. In order that these assumptions are communicated to the hydrogeologists, a methodology has been developed for representing uncertainty in the 3D geological models. An important part of the uncertainty representation, is the development of a fracture zone classification in which the uncertainty in both the presence and the geometry of the fracture zone is assigned. Other elements include the development of alternative models, visualisation of raw data, development of conceptual models, development of bounding models, and suitable quality assurance and archiving of modelling projects.

The Inpluence of Borehole Flushing on the Concentration of Microbes in Granitic Groundwaters.

1993 ◽  
Vol 333 ◽  
Author(s):  
S. Stroes-Gascoyne ◽  
M. Gascoyne ◽  
C.J. Hamon ◽  
D. Jain ◽  
P. Vilks
Keyword(s):  
Fracture Zone ◽  
Research Laboratory ◽  
Microbial Growth ◽  
Management Program ◽  
Flow Rates ◽  
Particle Count ◽  
Tenfold Increase ◽  
Total Particle ◽  
Underground Research Laboratory ◽  
Nuclear Fuel Waste

ABSTRACTA number of groundvater parameters have been studied at AECL’s Underground Research Laboratory (URL) in support of the Canadian Nuclear Fuel Waste Management Program. The concentration of microbes in groundvater is of interest as they may modify the transport of dissolved radionuclides. Preliminary results from an earlier study suggested that the microbe concentrations may be affected by the extent of borehole flushing prior to sampling. A study was therefore carried out in which packer-isolated intervals of two boreholes intersecting a fracture zone at 250-m depth in the URL were flushed and sampled on two occasions at various flow rates. High initial microbial concentrations (most likely due to leaching of nutrients from sample tubes) decreased rapidly as flushing progressed, suggesting enhanced microbial growth near the top of the borehole zone. Also, a tenfold increase in flow rate during flushing caused an increase in microbial concentrations in the groundwater of one of the boreholes, concurrent with an increase in total particle count. This suggests that particulate and biofilm material may be flushed out of the fracture zone at this particular location.

Technical Know-How for Modeling of a Geological Environment: Part 2—Geological Modeling

2010 ◽  
Author(s):  
Toshiyuki Matsuoka ◽  
Kenji Amano ◽  
Hideaki Osawa ◽  
Takeshi Semba
Keyword(s):  
Research And Development ◽  
Research Laboratory ◽  
Site Characterization ◽  
Initial Surface ◽  
Geological Environment ◽  
Know How ◽  
Environment Model ◽  
High Level ◽  
Underground Research Laboratory ◽  
The Impact

It is important for site characterization projects to manage the decision-making process with transparency and traceability and to transfer the technical know-how developed and accumulated during the research and development to the implementing phase as well as to future generations. The modeling of a geological environment supports efforts to clarify the degree of understanding regarding that geological environment, including uncertainty. Evaluation of the impact of uncertainties in a geological environment model is important to identify and prioritize key issues for further investigations. Therefore, a plan for site characterization should be made based on the results of the modeling. The aim of this study is to support the planning of initial surface-based site characterization based on the technical know-how accumulated from the Mizunami Underground Research Laboratory Project and the Horonobe Underground Research Laboratory Project. These projects are broad scientific studies of the deep geological environment that are a basis for research and development for the geological disposal of high-level radioactive wastes. In this study, the work-flow followed in developing the geological model, one of the geological environment models, and the related technical know-how acquired from literature data have been summarized.

Technical Know-How for Modeling of Geological Environment: Part 1—Overview and Groundwater Flow Modeling

2010 ◽  
Author(s):  
Hiromitsu Saegusa ◽  
Shinji Takeuchi ◽  
Keisuke Maekawa ◽  
Hideaki Osawa ◽  
Takeshi Semba
Keyword(s):  
Decision Making ◽  
Research And Development ◽  
Groundwater Flow ◽  
Research Laboratory ◽  
Site Characterization ◽  
Decision Making Process ◽  
Geological Environment ◽  
Flow Modeling ◽  
Know How ◽  
Underground Research Laboratory

It is important for site characterization projects to manage the decision-making process with transparency and traceability and to transfer the technical know-how accumulated during the research and development to the implementing phase and to future generations. The modeling for a geological environment is to be used to synthesize investigation results. Evaluation of the impact of uncertainties in the model is important to identify and prioritize key issues for further investigations. Therefore, a plan for site characterization should be made based on the results of the modeling. The aim of this study is to support for the planning of initial surface-based site characterization based on the technical know-how accumulated from the Mizunami Underground Research Laboratory Project and the Horonobe Underground Research Laboratory Project. These projects are broad scientific studies of the deep geological environment that are a basis for research and development for the geological disposal of high-level radioactive wastes. In this study, the work-flow of the groundwater flow modeling, which is one of the geological environment models, and is to be used for setting the area for the geological environment modeling and for groundwater flow characterization, and the related decision-making process using literature data have been summarized.

Mizunami Underground Research Laboratory in Japan: Pre-Excavation Site Characterization and Influence on Design Concepts

2001 ◽  
Author(s):  
Glen F. McCrank ◽  
Kenji Amano ◽  
Kaoru Koide ◽  
Hiroya Matsui ◽  
Shinichiro Mikake ◽  
...  
Keyword(s):  
Research Laboratory ◽  
Conceptual Models ◽  
Site Characterization ◽  
Geological Environment ◽  
Central Japan ◽  
Design Concepts ◽  
Experimental Programme ◽  
Nuclear Cycle ◽  
Underground Research Laboratory ◽  
Excavation Site

Abstract The Mizunami Underground Research Laboratory (MIU) will be constructed by the Japan Nuclear Cycle Development Institute (JNC) in central Japan. The project is planned in three overlapping phases consisting of I) Surface-based Investigation II) Construction and III) Operations Phases. This paper addresses the methods used to investigate the geological environment, the integration of the site knowledge into conceptual models and the application of the knowledge in designing the facility; some aspects of the future experimental programme are discussed.

Hydrogeological Characterization on Surface-Based Investigation Phase in the Mizunami Underground Research Laboratory Project, in Japan

2007 ◽  
Author(s):  
Hiromitsu Saegusa ◽  
Hironori Onoe ◽  
Shinji Takeuchi ◽  
Ryuji Takeuchi ◽  
Takuya Ohyama
Keyword(s):  
Phase I ◽  
Research Laboratory ◽  
Phase Iii ◽  
Geological Environment ◽  
Hydrogeological Model ◽  
Central Japan ◽  
Energy Agency ◽  
Flow Simulations ◽  
Underground Research Laboratory ◽  
Operation Phase

The Mizunami Underground Research Laboratory (MIU) project is being carried out by Japan Atomic Energy Agency in the Cretaceous Toki granite in the Tono area, central Japan. The MIU project is a purpose-built generic underground research laboratory project that is planned for a broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes. One of the main goals of the MIU project is to establish comprehensive techniques for investigation, analysis, and assessment of the deep geological environment. The MIU project has three overlapping phases: Surface-based Investigation (Phase I), Construction (Phase II) and Operation (Phase III). Hydrogeological investigations using a stepwise process in Phase I have been carried out in order to obtain information on important properties such as, location of water conducting features, hydraulic conductivity and so on. Hydrogeological modeling and groundwater flow simulations in Phase I have been carried out in order to synthesize these investigation results, to evaluate the uncertainty of the hydrogeological model and to identify the main issues for further investigations. Using the stepwise hydrogeological characterization approach and combining the investigation with modeling and simulation, understanding of the hydrogeological environment has been progressively improved.

Current Status of Phase II Investigations: Mizunami Underground Research Laboratory (MIU) Project

2009 ◽  
Author(s):  
Tadahiko Tsuruta ◽  
Masahiro Uchida ◽  
Katsuhiro Hama ◽  
Hiroya Matsui ◽  
Shinji Takeuchi ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Research Laboratory ◽  
Total Duration ◽  
Geological Mapping ◽  
Phase Iii ◽  
Current Status ◽  
Geological Environment ◽  
Deep Underground ◽  
Underground Research Laboratory

The Mizunami Underground Research Laboratory (MIU) Project, a comprehensive research project investigating the deep underground environment in crystalline rock, is being conducted by the Japan Atomic Energy Agency at Mizunami City, Central Japan. The MIU Project is being carried out in three overlapping phases: Surface-based Investigation (Phase I), Construction (Phase II), and Operation (Phase III), with a total duration of 20 years. The overall project goals of the MIU Project from Phase I through to Phase III are: 1) to establish techniques for investigation, analysis and assessment of the deep geological environment, and 2) to develop a range of engineering techniques for deep underground application. Phase I was completed in March 2004, and Phase II investigations associated with the construction of the underground facilities are currently underway. Phase II investigation goals are to evaluate the geological, hydrogeological, hydrogeochemical and rock mechanical models developed in Phase I and to assess changes in the deep geological environment caused by the construction of underground facilities. Geological mapping, borehole investigations for geological, hydrogeological, hydrochemical and rock mechanical studies are being carried out in shafts and research galleries in order to evaluate the models. Long-term monitoring of changes in groundwater chemistry and pressure associated with the construction of the underground facilities continue in and around the MIU site, using existing boreholes and monitoring systems. This report summarizes the current status of the MIU Project on results of the Phase II investigations to date.

Low Alkaline Cement Used in the Construction of a Gallery in the Horonobe Underground Research Laboratory

2010 ◽  
Author(s):  
Masashi Nakayama ◽  
Haruo Sato ◽  
Yutaka Sugita ◽  
Seiji Ito ◽  
Masashi Minamide ◽  
...  
Keyword(s):  
Fly Ash ◽  
Research Laboratory ◽  
Concrete Lining ◽  
Energy Agency ◽  
Tunnel Support ◽  
Long Term Stability ◽  
Alkaline Conditions ◽  
High Level ◽  
Underground Research Laboratory

In Japan, any high level radioactive waste (HLW) repository is to be constructed at over 300 m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various admixtures. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (Highly Fly-ash Contained Silicafume Cement), containing over 60 wt% of silica-fume (SF) and fly-ash (FA). HFSC was used experimentally as the shotcrete material in construction of part of the 140m deep gallery in the Horonobe Underground Research Laboratory (URL). The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40 wt% OPC (Ordinary Portland Cement), 20 wt% SF, and 40 wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC. The total length of tunnel using HFSC shotcrete is about 73 m and about 500 m3 of HFSC was used. The workability of HFSC shotcrete was confirmed in this experimental construction.

Sign in / Sign up

Export Citation Format

Share Document