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Maekawa, Keisuke; Saegusa, Hiromitsu; Inaba, Kaoru*; Shimogochi, Takafumi*
JAEA-Research 2010-001, 238 Pages, 2010/07
JAEA-Research-2010-001.pdf:30.2MB
In the design and safety assessment of the geological disposal system of the high-level radioactive waste (HLW), it is extremely important to improve the reliability of the evaluation of the investigation of the geological environment, which provides technical basis. Especially, the knowhow and the experience of groundwater flow modeling based on the data acquired in deep underground at the coastal area are needed to be enhanced because these are little. Against this background, we have carried out modeling and groundwater flow simulation of the Horonobe coastal area. The knowledge and the knowhow acquired through this work were accumulated and arranged as a knowledge base by executing the following items. (1)The discussion of applicability of the workflow of evaluation of the groundwater flow for the coast region, and extension and update according to need. (2)Understand of groundwater flow based on existing investigation result in Horonobe coastal area, (2-1)Estimation of distribution of salinity in groundwater, (2-2)Extraction and arrangement of knowhow and judgment basis in modeling and simulation works. As a result, the knowledge was expanded concerning the groundwater flow evaluation methodology needed in design and safety assessment of the geological disposal system that is able to correspond to various geological environments in our country.
Saito, Yuya; Tanai, Kenji; Takaji, Kazuhiko*; Shigeno, Yoshimasa*; Shimogochi, Takafumi*
JAEA-Research 2009-065, 76 Pages, 2010/03
JAEA-Research-2009-065.pdf:23.92MB
The 3-D mechanical coupled analysis technique for the long term mechanical behavior of near field is developed. The object of analysis is extended to the disposal gallery and the near field rock, in addition to the buffer material and the overpack for previous one. The analysis model is developed with a degradation model of concrete support and modeling of the near field rock with the valuable- compliance-type constitutive equation. The remaining problems of current study are related to; (1) mechanical property and modeling of backfill material, (2) adopting a degradation model of concrete support in the prototype model, (3) examining the effect of analytical model mesh and time step for the 3-D mechanical coupled analysis. We conducted the one-dimensional consolidation test for the backfill material. The backfill material shows a similar behavior to that of buffer material. And the prototype model is developed adopting a degradation model for a concrete support and examining the effect of the model mesh and time step.
Nishimura, Mayuka; Tanai, Kenji; Takaji, Kazuhiko*; Shigeno, Yoshimasa*; Shimogochi, Takafumi*
JAEA-Research 2007-004, 87 Pages, 2007/03
JAEA-Research-2007-004.pdf:14.61MB
The 3-D mechanical coupled analysis technique for the near field is developed, upgrading a 2-D non-coupled technique for the buffer material. The analysis object is extended to the disposal gallery and the near field rock, in addition to the EBS. And following problems are approached; (1) modeling the near field rock with the valuable- compliance-type constitutive equation, (2) modeling a degraded behavior of the concrete support, (3) changing the expanding deform method of the overpack corrosion, (4) examining the effect of drainage conditions on water pressure behavior of the near field rock, (5) setting parameters of the backfill material modeled with Sekiguchi-Ohta model. The prototype model is developed adopting the result for the above approaches, excluding a degradation model of concrete support. The result of long term analysis with the prototype model shows a reasonable behavior of the near field that reflects the models of the near field rock and the backfill material.
Takaji, Kazuhiko*; Shigeno, Yoshimasa*; Shimogochi, Takafumi*; Hirai, Takashi*; Shiratake, Toshikazu*
JNC TJ8440 2004-011, 200 Pages, 2005/02
JNC-TJ8440-2004-011.pdf:5.05MB
On the R&D of the high-level radioactive waste repository, it is essential that Engineered Barrier System (EBS) is stable mechanically over along period of time for maintaining each ability required to EBS. After closing the repository, the various external forces will be affected to buffer intricately for along period of time. So, to make clear the mechanical deformation behavior of buffer against the external force is important, because of carrying out safety assessment of EBS accurately. In this report, several sets of parameters are chosen for the previously selected two constitutive models, Sekiguchi-Ohta model and Adachi-Oka model, and the element tests and mock-up tests are simulated using these parameters. Through the simulation, applicability of the constitutive models and parameters is examined. Moreover, simulation analyses of EBS using these parameters were carried out, and mechanical behavior is evaluated over a long period of time. Analysis estimated the amount of settlement of the over pack, the stress state of buffer material, the reaction force to a base rock, etc., and the result that EBS is mechanically stable over a long period of time was obtained. Next, in order to prove analyses results a side, literature survey was conducted about geological age, the dynamics history of a Smectite layer. The outline plan was drawn up about the natural analogue verification method and preliminary examination was performed about the applicability of
Takaji, Kazuhiko*; Shigeno, Yoshimasa*; Shimogochi, Takafumi*
JNC TJ5400 2004-002, 89 Pages, 2005/02
JNC-TJ5400-2004-002.pdf:12.07MB
None
Takaji, Kazuhiko*; Shigeno, Yoshimasa*; Shimogochi, Takafumi*
JNC TJ5400 2003-007, 120 Pages, 2004/04
JNC-TJ5400-2003-007.pdf:1.76MB
In the Horonobe underground research project, a creep examination of a rock and buffer material, a tunnel closing examination, a fixed accuracy confirmation examination and a T-H-M-C examination, etc. is planned. These field examinations are aimed at the illustration and evaluation of applicability of the Engineered Barrier System (EBS) design method under the detailed geological environment shown in the H12 report, understanding of long-term phenomenon for EBS, and improvement in reliability of the prediction method. Then, in order to examine the specifications of the bentonite mixture material in design of a field test, the in-situ examination using artificial groundwater which imitated the groundwater of Horonobe and NaCl solution was carried out, and the mechanical behavior of the bentonite mixture material under the sea water environment assumed in the location of the field examination in Horonobe has been grasped. Moreover, in order to confirm the applicability of the prediction technique of the long-term behavior of an engineered barrier, overpack sinking behavior using the result of an in-situ examination etc. was analyzed.
Takaji, Kazuhiko*; Shigeno, Yoshimasa*; Shimogochi, Takafumi*; Shiratake, Toshikazu*; Tamura, Hirokuni*
JNC TJ8440 2003-007, 218 Pages, 2004/02
JNC-TJ8440-2003-007.pdf:4.43MB
On the R. and D. of the high-level radioactive waste repository, it is essential that Engineered Barrier System (EBS) is stable mechanically over a long period of time for maintaining each ability required to EBS. After closing the repository, the various external forces will be affected to buffer intricately for a long period of time. So, to make clear the mechanical deformation behavior of buffer against the external force is important, because of carrying out safety assessment of EBS accurately.In this report, several sets of parameters are chosen for the previously selected two constitutive models, Sekiguchi-Ohta model and Adachi-Oka model, and the element tests and mock-up tests are simulated using these parameters. Through the simulation, applicability of the constitutive models and parameters is examined.Moreover, simulation analyses of EBS using these parameters were carried out, and mechanical behavior is evaluated over a long period of time. Analysis estimated the amount of settlement of the over pack, the stress state of buffer material, the reaction force to a base rock, etc., and the result that EBS is mechanically stable over a long period of time was obtained. Next, in order to prove analyses results a side, literature survey was conducted about geological age , the dynamics history of a Smectite layer.The outline plan was drawn up about the natural analogue verification method and preliminary examination was performed about the applicability of "Freezing Sampling".
Maekawa, Keisuke; Saegusa, Hiromitsu; Inaba, Kaoru*; Shimogochi, Takafumi*
no journal, ,
no abstracts in English
Maekawa, Keisuke; Saegusa, Hiromitsu; Inaba, Kaoru*; Shimogochi, Takafumi*
no journal, ,
no abstracts in English