Development of evaluation for swelling characteristics of bentonite based buffer under water-chemistry condition of high level radioactive waste disposal facility
| Project/Area Number |
14350249
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Geotechnical engineering
|
|---|
| Research Institution | Ibaraki University |
|---|
Principal Investigator |
KOMINE Hideo Ibaraki University, the College of Engineering, Associate Professor, 工学部, 助教授 (90334010)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YASUHARA Kazuya Ibaraki University, the College of Engineering, Professor, 工学部, 教授 (20069826)
MURAKAMI Satoshi Ibaraki University, the College of Engineering, Research Assistant, 工学部, 助手 (10261744)
CHIJIMATSU Masakazu Hazama corporation, Researcher, 技術環境本部原子力部, 研究員
|
|---|
| Project Period (FY) |
2002 – 2004
|
| Project Status |
Completed (Fiscal Year 2004)
|
| Budget Amount *help |
¥11,500,000 (Direct Cost: ¥11,500,000)
Fiscal Year 2004: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2003: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2002: ¥5,800,000 (Direct Cost: ¥5,800,000)
|
|---|
| Keywords | High-level radioactive waste / Bentonite / Swelling pressure / Swelling deformation / Water chemistry / Physico-chemistry / Diffuse double layer theory / Laboratory test |
|---|
| Research Abstract |
Disposal of high-level radioactive wastes exhausted from nuclear power plants is an important problem that should be solved in the 21st century. In this plan, there is a material that is called"Bentonite based buffer material"in one of the multiple barriers. Bentonite based buffer material fills up a space between waste container and surrounding bedrock Moreover, a disposal facility has the possibility that is constructed in the vicinity of the coastal zone by the convenience of the wastes form transportation.
To contribute this project, this study aimed to evaluate the self sealing behavior of bentonite based buffer material in the seawater condition quantitatively, and to establish design method of bentonite based buffer material from a viewpoint of self-sealing property under seawater condition.
In this study,"self-sealing test by the one-dimensional model"was done in the beginning, and the self-sealing behavior in the seawater condition was investigated. This experiment is one-dimens
… More
ional model test to imitate the self-sealing behavior of seawater condition by installing a space that scales down the relation between the space part of an actual disposal site and the buffer material in the one dimension, and supplying artificial seawater of a different concentration.
Next, the factor thought to be influence on the self sealing behavior was investigated Concretely, the invasion situation of the seawater element in the pore water of the specimen was investigated by measuring each cation exchange capacity (EXC) and exchangeable cation (CEC) of Na^+, Ca^<2+>, K^+, and Mg^<2+> ions in the specimen after it experimented.
In addition, the equation that was appreciable of self-sealing behavior under seawater condition was made by building the empirical equation based on the result of this experiment into the self-sealing behavior of the buffer material in the distilled water condition to forecast and appreciable"equations for evaluating the swelling behavior".
The new finding obtained for this research is shown below.
1.In the following conditions, it has been understood that influence of seawater on self-sealing behavior is small from this self sealing test. In the bentonite A, if the space is 1.25mm or less and concentration of supplied solution is 100% or less of sea concentration, it has been understood that influence of seawater is small. And in the bentonite B and E, if the space is 1.25mm or less and concentration of supplied solution is 10% or less of sea concentration, it has been understood that influence of seawater is small.
2.It was shown that there was a possibility because of seawater was not infiltrated in the space of the buffer material as one of the reasons for the decrease in self-sealing behavior is small under the seawater condition. The filter ability of cation in seawater by montmorillonite crystalline layer is thought as this mechanism. And it is thought that this function works effectively by hardening the bentonite well-set.
3.Though the applicability was limited in this experiment condition, the equation that was appreciable of self sealing behavior under seawater condition was made by building the empirical equation based on the result of this experiment into"equations for evaluating the swelling behavior by Komine and Ogata".
4.Synthesizing the above-mentioned result, design method was constructed from viewpoint of self sealing property under seawater condition. Less
|
Report
(4 results)
Research Products
(20 results)
