Development of mechanical coupled analysis technique for the long term behavior of the near field, 2

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.

Experimental study on the effects of fault movement on the engineered barrier system

Naito, Morimasa; Saito, Yuya; Tanai, Kenji; Yui, Mikazu

Journal of Power and Energy Systems (Internet), 3(1), p.158 - 169, 2009/00

https://doi.org/10.1299/jpes.3.158

An experimental approach is introduced for understanding how the engineered barriers of a deep geological repository system are affected by fault movement. The experiments are conducted using laboratory simulation test equipment. So far, the experiments indicate that the metal overpack is rotated within the bentonite buffer due to its plasticity, but not breached. Numerical analyses are also carried out to supplement the range of the experiments, which is limited by the capability of the test equipment.

Assessment on mechanical effect of engineering barrier system to fault movement, 2

Saito, Yuya; Tanai, Kenji; Kikuchi, Hirohito*; Hirai, Takashi*; Nishimura, Mayuka*

JAEA-Research 2008-010, 35 Pages, 2008/03

JAEA-Research-2008-010.pdf:15.56MB

Site with the potential to adversely affect the performance of the disposal system should be avoided by site selection in Japan. On the other hand, according to Atomic Energy Commission, the possibility to occur the natural and artificial events suddenly should be examined. So it is important to examine about the critical state of the engineering barrier system (EBS) when if the fault move across the EBS. And this study helps to be understood by the nation. In this paper, we examined the influence of the velocity of fault movement by the model test, and tried to improve the precision of the simulation analysis. Test results showed that the total pressure of the buffer inside was about 20% decreased when the velocity was a one-tenth. And it is important to set the permeability of the near-field rock appropriately when simulating the behavior of the buffer material affected by fault movement.

Development of the design method for HLW repository

Matsumoto, Kazuhiro; Saito, Yuya; Tanai, Kenji

no journal, , 

no abstracts in English