Study on the System Development for evaluating Long-term Alteration of Hydraulic Field in Near Field (IV) (Summary)

Okutsu, Kazuo*; Morikawa, Seiji*; Shimbo, Hiroshi*; Kuroyanagi, Mikio*; Sahara, Fumihiro*; Murakami, Takeshi*; Aoyama, Yuji*

JNC TJ8400 2005-013, 117 Pages, 2005/02

JNC-TJ8400-2005-013.pdf:3.24MB

To integrate the system for evaluation of long-term hydraulic condition in near field of TRU waste disposal, the engineered barrier, which consists of bentonite buffer and cementitious materials, was employed in the series of laboratory tests. On the bentonite buffer, with the aim of investigating of the effect of (i) interlayer cation in bentonite, (ii) content of siliceous sand and (iii) the ionic strength of ground water on its mechanical and hydraulic properties, series of laboratory tests were conducted. The same lot of bentonite was used in the series of tests to obtain consistent data. In addition, the swelling test of the laminated bentonite with caliumization front was conducted for verification of the proposed constitutive model. On cementitious materials, the altered specimen that produced immersing was investigated the water permeation and also characteristics. The hardened cement paste specimens with W/C=40 to 105% were immersed into deionized water and alteration behavior under diffusion condition was investigated.

Study on the System Development for Evaluating Long-Term Alteration of Hydraulic Field in Near Field, 3 (Summary)

Okutsu, Kazuo*; Morikawa, Seiji*; Taguchi, Katsunori*; Kuroyanagi, Mikio*; Sahara, Fumihiro*; Takase, Hiroyasu*; Aoyama, Yuji*

JNC TJ8400 2003-087, 199 Pages, 2004/02

JNC-TJ8400-2003-087.pdf:4.82MB

The system development for evaluating the long-term alteration of hydraulic field in near field was examined. The "Evidential Support Logic" for ensuring the long-term stability of the repository was developed and evaluated. Furthermore, the developed chemical/mechanical alteration action analysis system was verified and improved. The system was coupled for the long-term alteration evaluation analysis.

Study on the System Development for Evaluating Long-Term Alteration of Hydraulic Field in Near Field II (Summary)

Okutsu, Kazuo*; Morikawa, Seiji*; Takamura, Hisashi*; Hane, Koji*; Tabei, Kazuto*; Sahara, Fumihiro*; Murakami, Takeshi*

JNC TJ8400 2003-050, 140 Pages, 2003/02

JNC-TJ8400-2003-050.pdf:3.13MB

The system development for evaluating long-term alteration of hydraulic field in Near Field was examined.

Evaluation of the long-term mechanical behavior in the near field considering chemical transitions of barrier materials

Sahara, Fumihiro*; Murakami, Takeshi*; Ito, Hiroyuki*; Mihara, Morihiro; Oi, Takao

no journal, , 

In order to make a reliable evaluation of the performance of TRU waste repository, development of a system that evaluates long-term transition of the hydraulic field in the near-field which takes into account the time-dependent alteration of barrier material properties is required. As part of this effort, Mechanical Analysis system considering Chemical transition of BEntonite-based and CEment-based materials (MACBECE) was developed. MACBECE firstly calculates deformations of barrier materials based on the chemical property changes and creep deformation of the host rock and consequently evaluates the hydraulic conductivity of barrier materials. By using MACBECE, the long-term deformation and the transition of hydraulic field for disposal cavities with circular cross section were evaluated, using an assumed chemical evolution as input. The analysis results indicated that the deformation of the engineered barriers depended strongly on the displacement of the tunnel wall by the creep of host rock, i.e., when the displacement of the wall was small, the deformation of the barrier materials was negligible in spite of acting swelling pressure of the buffer material. On the other hand, when the displacement is not small, the thickness of buffer material decreases, but the density increases due to compaction, therefore it is possible that the influence on the nuclide migration is not significant.

Development of the Integrated System for Repository Engineering (iSRE), 4; Current status of the prototype of the iSRE

Yoshino, Hiroyuki*; Fujisawa, Yasuo*; Kobayashi, Yuichi*; Sugita, Yutaka; Kageyama, Takeshi; Hane, Koji*; Sahara, Fumihiro*; Yabuki, Nobuyoshi*; Makanae, Koji*

no journal, , 

This paper reports development of ISRE (the Integrated System for Repository Engineering), as a knowledge management tool on the repository design and engineering technology, which manages and inherits the information and knowledge of each phase of the disposal project of the radioactive waste during around 100 years, which also enables reasonable design of the repository by using accumulated and integrated information. Content of this paper is current status of the prototype of the iSRE.

Development of the Integrated System for Repository Engineering (iSRE), 6; Expansion of function for practical use of the iSRE

Numata, Taro*; Fujisawa, Yasuo*; Kobayashi, Yuichi*; Sugita, Yutaka; Kageyama, Takeshi; Hane, Koji*; Sahara, Fumihiro*; Yabuki, Nobuyoshi*; Makanae, Koji*

no journal, , 

This paper reports development of ISRE (the Integrated System for Repository Engineering), as a knowledge management tool on the repository design and engineering technology, which manages and inherits the information and knowledge of each phase of the disposal project of the radioactive waste during around 100 years, which also enables reasonable design of the repository by using accumulated and integrated information. Content of this paper is expansion of function for practical use of the iSRE.