Hydrochemical investigation at the Mizunami Underground Research Laboratory; Compilation of groundwater chemistry in the Mizunami group and Toki granite area (April, 2004 - March, 2008)

Sai, Masataka; Hagiwara, Hiroki; Matsushima, Hiroyuki*; Noda, Masatoshi*; Noda, Masaru*; Ando, Kenichi*; Tanaka, Tatsuya*; Ueda, Tadashi*; Honda, Yuko*; Mizuno, Takashi

JAEA-Data/Code 2010-010, 75 Pages, 2010/09

JAEA-Data-Code-2010-010.pdf:2.5MB

This report compiles data set of the groundwater chemistry obtained at Mizunami Underground Research Laboratory (MIU) between the fiscal year 2004 and the fiscal year 2007. These data includes groundwater chemistry of inflow in the shafts and sampled groundwater in the boreholes, which drilled from sub-stages of MIU and from surface (MSB-2, MSB-4, and MIZ-1). Basic information (e.g. sampling location, sampling date, sampling method, analytical method) are also described in terms of quality control and traceability.

Study on grouting performance for underground construction in crystalline rock, 3; Numerical simulation of water-tightness improvement

Tanaka, Tatsuya*; Matsui, Hiroya; Hashimoto, Shuji*; Ando, Kenichi*; Takeuchi, Shinji; Saegusa, Hiromitsu

Dai-38-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu (CD-ROM), p.143 - 148, 2009/01

This study aims to establish techniques for grouting, and evaluation of the effects of grouting on the geological environment, to be applied in the field of high level radioactive waste disposal in the deep underground. A block-scale hydrogeological model has been generated using discrete fracture networks based on data obtained from the short-borehole investigation campaign performed at the research tunnel around which grouting has been carried out. The grouting performance in terms of reducing the water inflow rate was evaluated by groundwater flow simulation. Lessons learned applicable to future studies of in-situ testing have been addressed.

Hydraulic tomography in fractured granite; The Mizunami Underground Research Site, Japan

Illman, W. A.*; Liu, X.*; Takeuchi, Shinji; Yeh, T.-C. J.*; Ando, Kenichi*; Saegusa, Hiromitsu

Water Resources Research, 45(1), p.W01406_1 - W01406_18, 2009/00

https://doi.org/10.1029/2007WR006715

Two large-scale cross-hole pumping tests were conducted at separate locations in deep boreholes at the Mizunami Underground Research Laboratory (MIU) construction site in central Japan. We analyze the two cross-hole tests using the transient hydraulic tomography (THT) code to compute the hydraulic conductivity () and specific storage () tomograms, as well as their uncertainties in three-dimensions. The equivalent and obtained using asymptotic analysis served as the initial parameter estimates for the 3D stochastic inverse modeling effort. Results show several, distinct high and low zones that are continuous over hundreds of meters, which appear to delineate fault zones and their connectivity. The THT analysis of the tests also identified a low zone which corresponds with a known fault zone trending NNW and has been found to compartmentalize groundwater flow at the site. These results corroborate well with several hydrogeological phenomena around the site.

Study of evaluation for hydraulic properties with the single borehole-Hydraulic test

Hashimoto, Shuji*; Tanaka, Tatsuya*; Ando, Kenichi*; Takeuchi, Shinji; Saegusa, Hiromitsu; Kim, H.*

Dai-36-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu (CD-ROM), p.419 - 424, 2007/01

no abstracts in English

Gas generation and migration analysis for TRU Waste Disposal in Japan

Ando, Kenichi*; Mihara, Morihiro; Noda, Masaru*; Yamamoto, Mikihiko*

Proceedings of 11th International High-Level Radioactive Waste Management Conference (IHLRWM) (CD-ROM), p.655 - 662, 2006/00

This study focus on gas generation associated with metal corrosion, bio-degradation of organic materials and radiolysis and gas migration through the engineered barrier system (EBS) into the surrounding host rock. Two Phase Flow analysis was performed and evaluated in terms of the development of gas pressure and discharged water from the EBS. In addition radioactive gas transport from the repository and across the reference land surface, and resaturation behavior were examined.

Viscosity and density measurements of melts and glasses at high pressure and temperature by using the multi-anvil apparatus and synchrotron X-ray radiation

Otani, Eiji*; Suzuki, Akio*; Ando, Ryota*; Urakawa, Satoru*; Funakoshi, Kenichi*; Katayama, Yoshinori

Advances in High-Pressure Technology for Geophysical Applications, p.195 - 209, 2005/09

https://doi.org/10.1016/B978-044451979-5.50012-0

This paper summarizes the techniques for the viscosity and density measurements of silicate melt and glasses at high pressure and temperature by using the X-ray radiography and absorption techniques in the third generation synchrotron radiation facility, SPring-8, Japan. The falling sphere method using in situ X-ray radiography makes it possible to measure the viscosity of silicate melts to the pressures above 6 GPa at high temperature. We summarize the details of the experimental technique of the viscosity measurement, and the results of the measurements of some silicate melts such as the albite and diopside-jadeite systems. X-ray absorption method is applied to measure the density of the silicate glasses such as the basaltic glass and iron sodium disilicate glass up to 5 GPa at high temperature. A diamond capsule, which is not reactive with the glass, is used for the density measurement of the glasses. The present density measurement of the glasses indicates that this method is useful for measurement of the density of silicate melts at high pressure and temperature.

Evaluation of Multiple Well Test Simulatous by Applying Field Measurement Data

Noda, Masaru*; Ando, Kenichi*; Tanaka, Tatsuya*

JNC TJ7400 2005-068, 133 Pages, 2004/03

JNC-TJ7400-2005-068.PDF:4.55MB

The objectives of this study is to evaluate the applicability of several well test simulators using field data. Single hole well test is effective method to evaluate hydraulic conductivity using a borehole. Recently comprehensive well test and interactive software for computer-aided interpretation of well test have been developed. Especially deep geological condition with low permeability domain requires more effective method. This study motivates for selecting different interpretation codes like AQTESOLV as a semi-analytical codes, nSights and MULTISIM as a historical matching type graphical inverse code, and TOUGH2/ITOUGH2 as a FDM inverse code. Then all codes apply to three categorized data, that one is theoretical data as a code evaluation, then two data are from real field to demonstrate that not only codes but also processes may affect the result. Finally evaluation of codes, fluctuation of hydraulic property, and code specific handling are studied and the basis for well test strategy is obtained.

Three-dimensional inverse modeling of two large-scale cross-hole hydraulic tests in fractured granite at the Mizunami Underground Research Laboratory site, Japan

Illman, W. A.*; Liu, X.*; Yeh, J.*; Ando, Kenichi*; Takeuchi, Shinji; Saegusa, Hiromitsu

no journal, , 

Two cross-hole tests were conducted at separate locations in deep boreholes at the MIU construction site in central Japan. We analyze the two cross-hole hydraulic tests using the Transient Hydraulic Tomography (THT) code of Zhu and Yeh [2005] to compute the hydraulic conductivity (K) and specific storage (Ss) distributions as well as their uncertainties in three-dimensions. The equivalent K and Ss were obtained using the asymptotic analysis served as the initial parameter estimates for the 3D stochastic inverse modeling effort. Results show 2 distinct high K and low Ss zones that are continuous over distances ranging from 550 - 1,200 m, which delineate 2 separate fault zones. The fault zones that are imaged through THT correlate well with available geological data and drawdown records. The analysis of the tests with the THT code also identified a low K zone which corresponds with a known fault zone trending NNW and has been found to compartmentalize groundwater flow at the site.

Estimation of upscaled hydraulic conductivity profiles along a borehole in low permeability crystalline rock using discrete fracture network models

Hashimoto, Shuji*; Saegusa, Hiromitsu; Tanaka, Tatsuya*; Ando, Kenichi*; Bruines, P.*

no journal, , 

It is useful to estimate profiles of the equivalent hydraulic conductivity for groundwater flow modeling based on an equivalent porous medium approach that are used for hydrogeological characterization at over the several kilometers scale. In this study, a combined interpretation of core observations, BTV and fluid logging has been used to identify and classify water-conducting features (WCFs) among observed fractures in deep boreholes around the MIU construction site in Phase I. Transmissivity profiles of WCFs were determined by the interpretation of fluid logging and the results of short interval packer tests. An equivalent hydraulic conductivity for the sub-divided block is calculated using a hydraulic discrete fracture network (hydroDFN) model based on the information, and is confirmed the validity using long interval packer test results. Groundwater flow analyses using developed hydroDFN model are also carried out to assess groundwater flow conditions around galleries.

Modelling and numerical analyses for assessing groundwater flow and groundwater chemistry at a coastal area; A Case study of Horonobe area, Hokkaido, Japan

Maekawa, Keisuke; Saegusa, Hiromitsu; Matsuo, Shigeaki*; Hashimoto, Shuji*; Ando, Kenichi*

no journal, , 

no abstracts in English