Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Hama, Katsuhiro; Iwasaki, Riyo*; Morikawa, Keita*
JAEA-Technology 2017-015, 45 Pages, 2017/07
JAEA-Technology-2017-015.pdf:16.57MB
Tono Geoscience Center of Japan Atomic Energy Agency has been carrying out the Mizunami Underground Research Laboratory Project. The goal of mass transport study is to obtain a better understanding of mass transport phenomena in the geological environment as well as to develop technologies for measurement of the mass transport parameters, model construction, numerical analysis and validation of those technologies. This experiment was planned to understand the influence of the microscopic structure in the rock mass on the mass transport property. The diffusion experiment using rock sample was carried out. The macroscopic and microscopic observations were carried out to understand the distribution of tracer (uranine) after the diffusion experiment. The uranine was observed in the plagioclase, in the grain boundary and in the microfracture in the mineral grains. These results suggested that distribution of mineral and of microfracture could affect the diffusion property of uranine.
Iwasaki, Riyo*; Hama, Katsuhiro; Morikawa, Keita*; Hosoya, Shinichi*
JAEA-Technology 2016-037, 62 Pages, 2017/02
JAEA-Technology-2016-037.pdf:8.69MB
Mass transport study is mainly performed as part of Phase III in the Mizunami Underground Research Laboratory Project. In Phase III, the goal of mass transport study is to obtain a better understanding of mass transport phenomena in the geological environment as well as to develop technologies for measurement of the mass transport parameters, model construction, numerical analysis and validation of those technologies. This study was planned to understand the influence of the geological characteristics of fracture on the mass transport parameters.
Department of Hot Laboratories
JAERI-Review 2002-039, 106 Pages, 2003/01
JAERI-Review-2002-039.pdf:9.46MB
no abstracts in English
Suzuki, Satoru; Sato, Haruo
JNC TN8410 2001-028, 36 Pages, 2002/03
JNC-TN8410-2001-028.pdf:1.81MB
For a safety assessment of the high-level radioactive waste disposal, effective diffusion coefficients (D
) of radionuclides in bentonite have been accumulated by the through-diffusion method. It has been found recently that experimental results on Ds for several cations (cesium and strontium) by the fairly standard experimental method in JNC differ from those previously reported in several papers. Discrepancy can be considered to be due to different design of diffusion cell and system. In order to confirm influences of the experimental design on cation diffusivities in bentonite, a flow-through diffusion system was developed and several diffusion experiments were conducted.As a result, magnitude of D and its salinity dependence were relatively different between the standard and flow-through diffusion system. Since the latter system can control boundary conditions of the experiment more strictly than the standard method, we can conclude that the flow-through diffusion system provide correct results. In addition, we apply this flow-through diffusion system to a modification of controlling boundary condition during the experiment and to the diffusion experiment under controlled temperature.
Sato, Haruo
PNC TN8410 97-202, 205 Pages, 1998/01
This thesis summarizes the results investigated in order to establish a basic theory on the predictive method of diffusion coefficients of nuclides in compacted sodium bentonite which is a candidate buffer material and in representative rocks for the geological disposal of radioactive waste by measuring the pore structural factors of the compacted bentonite and rocks such as porosity and tortuosity, measuring diffusion coefficients of nuclides in the bentonite and rocks, acquiring basic data on diffusion and developing diffusion models which can quantitatively predict nuclide migration in long-term. This consists of 7 chapters. Chapter 1 is the introduction, in which conventional studies on nuclide migration in buffer materials and rocks for the geological disposal of radioactive waste carried out to date are reviewed, and those problems are summarized as well as the objectives of this study are described. Besides, the difinition of geological disposal is explained. In Chapter 2, it is described on non-steady state diffusion of HTO, Sr-90, Tc-99, I-129, Cs-137, Np-237, Am-241 and Pu in purified sodium bentonite, Kunipia-F, in which the rate of constituent Na-smectite was raised approximately 100wt%. In-diffusion experiments were carried out in a range of bentonite densities of 200 
2000 kg
m
under ambient aerobic conditions at room temperature (20 23
C), and apparent diffusion coefficients (Da) were obtained. The apparent diffusion coefficients decreased with increasing dry density of bentonite. It was quantitatively indicated from diffusion experiments using HTO that these Da values include the effect of geometric retardation such as the tortuosity factor of compacted bentonite. It was experimentally clarified that Da is not affected by diffusion time based on diffusion experiments for different experimental periods using Sr and Cs. Moreover, it was also experimentally clarified that Da is not affected by tracer ...
Hama, Katsuhiro
no journal, ,
The development of modeling methodology for the mass transport in the geological environment is one of the important issues in the Mizunami Underground Research Laboratory Project. The main goal of this issue is to develop methodology for the characterization of mass transport property in the fractured crystalline rock. To achieve this goal, the study concerning mass transport phenomena in the Toki Granite should be carried out. The current status of this study has been presented.
Endo, Takashi*; Ishidera, Takamitsu; Terashima, Motoki; Tachi, Yukio
no journal, ,
To evaluate the colloid filtering function by compacted bentonite, colloidal stability tests and through-diffusion tests of dendrimer, a dendritic macromolecule, were carried out under high saline conditions. As a result, dendrimer can allow to evaluate the colloid filtering function of compacted bentonite under the high saline condition which has been difficult by conventional method.
Fukuda, Kenji; Murakami, Hiroaki; Itai, Kaori*; Ishibashi, Masayuki; Sasao, Eiji
no journal, ,
Matrix diffusion is one of the important for evaluating solute transport in granite. Diffusion of ions in granite pore water was studied in order to evaluate diffusivity in rock. Effective diffusion coefficient of uranine was measured using a diffusion cell. The effective diffusion coefficient of uranine in granite without fissure and alteration was found to be in the range 10
to 10
m
s
. The porosities of the granite samples were determined by observation of petrographic thin sections using entity fluorescence microscope. There was a positive correlation between the porosity larger than 1% and the effective diffusion coefficient.
Fukuda, Kenji; Ozaki, Yusuke; Murakami, Hiroaki; Itai, Kaori*; Ishibashi, Masayuki; Sasao, Eiji
no journal, ,
Matrix diffusion is one of the important for evaluating solute transport in crystalline rock. In this study, effective diffusion coefficient, porosity, and resistivity of crystalline rock were measured. There was a positive correlation between the formation factor calculated from the resistivity measurement and the effective diffusion coefficient calculated from the transmission diffusion test. Therefore, the effective diffusion coefficient can be estimated from the resistivity measurement of crystalline rock.