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Nomoto, Kosuke*; Matsui, Mikio*; Inoue, Hiroyuki*; Yoshino, Naoto; Karasaki, Kenji*; Ito, Kazumasa*
JNC TJ8400 2005-005, 94 Pages, 2005/02
In the safety assessment at geological disposal of High Level Nuclear Waste, it is necessary to understand several properties like hydrological, geological and chemical properties of the disposal site by site investigations. The investigation results should project to the ground water flow modeling, migration modeling and the parameter assignment of these models. Japan Nuclear cycle Development Institute is going to carry out two Underground Research Laboratory plans in order to push on with the project and help to make up the safety criteria of the geological disposal. Horonobe is one area of these plans. In Horonobe, following properties were identified./-There are saline and fresh water./-There is dissolved gas in the underground water./-The underground of some area has high water pressure./In this study, the analysis considering above properties were carried out for understanding of hydrological properties in sedimentary rock. In addition, the affection to the water flow and migration influenced by the results were examined.
Yoshino, Naoto; Miyanomae, Shunichi*; Inoue, Hiroyuki*; Nashimoto, Yutaka*
JNC TJ8400 2005-004, 166 Pages, 2005/02
In this paper, following two issues were examined and estimated, (1) The influence of near field condition factor to the dynamical behavior of sedimentary soft rock (2) The long term estimation of the dynamical behavior considering the condition of Horonobe area As the study about the influence of near field condition factor to the dynamical behavior of sedimentary soft rock, the thermal factor was focused on and the laboratory tests using test pieces which were sampled in Horonobe area were carried out under the water temperature were 20 degrees and 80 degrees. As a result, the time dependence parameter in variable-compliance-type constitutive-equation could be obtained. And comparison between creep property under 20 degrees and 80 degrees was conducted. In addition, the general properties of sedimentary soft rock under several conditions were identified by the survey of the literature. And the way how to confirm the dynamical properties of sedimentary soft rock with in-situ test were presented. For the study on the short-term and long-term stability of rock surroundig buffer materials, numerical simulations were carried out assuming several conditions. The direction of disposal tunnels and the ratio of rock strength by initial stress were estimated to be the main factor affecting the short-term stability of rock. Time dependency of rock and the stiffness of buffer material were estimated to be the main factor affecting the long-term stability of rock.
Yoshino, Naoto; Nomoto, Kosuke*; Matsui, Mikio*; Nashimoto, Yutaka*
JNC TJ8400 2004-035, 227 Pages, 2005/01
There are various uncertainty factors in the safety assessment for the geological disposal of High Level Nuclear Waste. And it is difficult to eliminate these uncertainty factors completely. Then it is important to evaluate the various uncertainty factors quantitatively for the safety assessment of the geological disposal. Japan Nuclear Cycle Development Institute focused on the groundwater flow analysis and studied about following issues in 2003 in order to quantify the variance of values which obtained by field investigation or numerical analysis. (1)The method to estimate the hydraulic conductivity and quantify the variability of estimated hydraulic conductivity. (2)The quantification of the key parameter's variability based on probability flow rate analysis. (3)Case study by the vertical two dimensional field. Two-dimensional numerical simulation program in which the uncertainty of the reach point in the ground water flow can be estimated was developed in above subjects. In this study, following three issues are studied (1)verification about the variance of the reach point estimated by 2-dimensional simulation program (2)development of 3-dimensional simulation program (3)Case study by 3-dimensional simulation program
Inoue, Hiroyuki*; Ishiguro, Takeshi*; Kuji, Masayoshi*; Yoshino, Naoto
JNC TJ8400 2004-014, 59 Pages, 2004/02
In this paper, authors examined the properties of sedimentary soft rock which might affect the groundwater flow rate and flow path in the sedimentary soft rock. As a general sample of sedimentary soft rock, we focused on the rock of HORONOBE area in HOKKAIDO prefecture. Then, following four issues were examined.1) a study of numerical flow rate analysis considering the difference of water density in the sedimentary soft rock.2) the hydro-geological modeling of HORONOBE area and a fundamental study of water pressure and saline density in HORONOBE area.3) a fundamental study of numerical coupling analysis about groundwater flow rate ,the difference of underground temperature, rock pressure and deformation. 4) a study about best performance of numerical flow rate analysis program.As a result, hydro-geological modeling of HORONOBE area using the information before 2002 as input data was succeeded by using the basic geological model which was made by IMAI et al,. And the applicability of TOUGH2 program as analysis method considering the density difference of underground water in sedimentary soft rock was verified. Then, we will be able to simulate underground flow considering the difference of saline density and specific water pressure in HORONOBE area. In addition, the applicability of TOUGH-FLAC program in which TOUGH2 was coupled with FLAC3D and consider rock pressure and deformation was verified. The best numerical performance of TOUGH2 program was studied in order to deal with large scale simulations. Then, it was shown that efficient method of the best numerical performance about TOUGH2 was possible.
Inoue, Hiroyuki*; Ishiguro, Takeshi*; Kuji, Masayoshi*; Yoshino, Naoto
JNC TJ8400 2004-013, 137 Pages, 2004/02
In this paper, authors examined the properties of sedimentary soft rock which might affect the groundwater flow rate and flow path in the sedimentary soft rock. As a general sample of sedimentary soft rock, we focused on the rock of HORONOBE area in HOKKAIDO prefecture. Then, following four issues were examined. 1) a study of numerical flow rate analysis considering the difference of water density in the sedimentary soft rock. 2) the hydro-geological modeling of HORONOBE area and a fundamental study of water pressure and saline density in HORONOBE area. 3) a fundamental study of numerical coupling analysis about groundwater flow rate ,the difference of underground temperature, rock pressure and deformation. 4) a study about best performance of numerical flow rate analysis program. As a result, hydro-geological modeling of HORONOBE area using the information before 2002 as input data was succeeded by using the basic geological model which was made by IMAI et al,. And the applicability of TOUGH2 program as analysis method considering the density difference of underground water in sedimentary soft rock was verified. Then, we will be able to simulate underground flow considering the difference of saline density and specific water pressure in HORONOBE area. In addition, the applicability of TOUGH-FLAC program in which TOUGH2 was coupled with FLAC3D and consider rock pressure and deformation was verified. The best numerical performance of TOUGH2 program was studied in order to deal with large scale simulations. Then, it was shown that efficient method of the best numerical performance about TOUGH2 was possible.
Inoue, Hiroyuki*; Yoshino, Naoto; Miyanomae, Shunichi*; Mizutani, Kazuhiko*; Noda, Kenji*
JNC TJ8400 2004-005, 161 Pages, 2004/02
In this study, the laboratory mechanical tests of sedimentary soft rock sampled at HORONOBE area in HOKKAIDO prefecture were conducted in order to build the confidence of OKUBO model for long term deformation of sedimentary rock. And the stability of rock around tunnel in building under the condition assumed the underground of HORONOBE area was examined by numerical simulation using information of boring data obtained before 2002 year. As a result, authors could obtain many values of parameter in OKUBO model under various conditions. These conditions have the difference of temperature and water saturation. In addition, the life time in creep predicted by OKUBO model could be compared with the real one. And numerical simulations, assuming various conditions such as stiffness of buffer material and yielding of support, had been carried out to evaluate the long-term stability of rock surrounding buffer material. Results show the decreasing tendency of time dependency of rock.
Yoshino, Naoto; Nashimoto, Yutaka*; Matsui, Mikio*; Ito, Setsuo*; Nomoto, Kosuke*
JNC TJ8400 2003-071, 63 Pages, 2004/01
In this paper authors focused on the uncertainty of the groundwater modeling, and following three issues are examined in order to estimate the spatial variance in the modeling field quantitatively; 1.The method to estimate the hydraulic conductivity and quantify the variability of estimated hydraulic conductivity. 2.The quantification of the key parameter's variability based on probability flow rate analysis. 3.Case study by the vertical two dimensional field.
Yoshino, Naoto; Sato, Hisashi*; Uchida, Masahiro
Saikuru Kiko Giho, (18), p.51 - 58, 2003/03
None
Ezaki, Tetsuro*; Jinno, Kenji*; *; *; Uchida, Masahiro; Yoshino, Naoto
JNC TY8400 2002-006, 164 Pages, 2002/06
no abstracts in English
Yoshino, Naoto; *
JNC TN8400 2002-001, 66 Pages, 2002/03
We have carried out the permeability tests and tracer tests using LABROCK (LABoratory test on mass transport in fractured ROCK) which was developed in order to get basic information relevant to the HLW geological disposal program. We have been focusing on the parallel single fracture and natural single fracture. Much knowledge about permeability and tracer transport was acquired as a result of examinations. This report summarize these knowledge. In future, we will measure the aperture of natural single fracture. If we will be able to develop the model of natural fracture based on measured aperture distribution and to explain permeability and tracer transport character described in this report, this research will play an important role in the HLW geological disposal program.
Ezaki, Tetsuro*; Jinno, Kenji*; Mitani, Yasuhiro*; *; Uchida, Masahiro; Yoshino, Naoto
JNC TY8400 2001-005, 93 Pages, 2001/06
no abstracts in English
Uchida, Masahiro; Yoshino, Naoto
JNC TN8410 2001-016, 36 Pages, 2001/05
This technical report summarizes sampling of the natural rock including conductive fracture. Hydraulic test was conducted at the target fracture prior to excavation. Objective of the sample was to reproduce same transmissivity at LABROCK by adjusting normal stress. This report was originally compiled by PNC in october, 1993.
Uchida, Masahiro; Yoshino, Naoto
JNC TN8410 2001-015, 35 Pages, 2001/05
This technical report summarizes excavation and preparation of the natural rock block sample used in LABROCK. This report was originally compiled by PNC in March, 1993.