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Imai, Hisashi*; Amemiya, Kiyoshi*; Matsui, Hiroya; Sato, Toshinori; Saegusa, Hiromitsu; Watanabe, Kunio*
Doboku Gakkai Rombunshu, C (Chiken Kogaku) (Internet), 69(3), p.285 - 296, 2013/07
The more accurate understanding and appropriate control of unsaturated area around tunnel excavated in deep rock-mass are required, for the geological isolation of radioactive waste project and also underground rock cavern storage project of liquefied petroleum gas. The numerical simulation of seepage flow is usually conducted to understand and evaluate the unsaturated zone around tunnel. The unsaturated parameters (such as moisture characteristic curve and relative permeability) and appropriate control of boundary condition are indispensable for the simulation. Authors developed methodology to measure unsaturated parameters utilizing the measuring method conventionally applied to soils and showed the efficiency of the method via a laboratory experiment. The idea of combining seepage face condition and flow rate fixed condition was derived, and the efficiency was shown in an model simulation. The two developments enabled the accurate estimation and understanding the evolution of unsaturated zone around tunnel.
Koibuchi, Hiroto; Dohi, Terumi; Nakagoshi, Akio*; Amemiya, Kiyoshi*
JAEA-Review 2008-035, 21 Pages, 2009/02
JAEA-Review-2008-035.pdf:1.28MB
Sub-surface disposal is one of the disposal methods for low-level radioactive waste in Japan. It will operate below the generally used depth domestically. The waste disposed by this method is assumed to be core internals and part of TRU (the transuranium elements) waste from reprocessing and MOX (mix oxide fuel) fuel fabrication facilities. These contain the waste generated as a result of research activities, too. In order to establish a safety regulation for the disposal, a case study of the overseas disposal is useful. The similar disposal plan of Japan has been considered or already operated especially in Finland and Sweden. Therefore, in this study, we investigated current status and concept of appropriate sub-surface disposal in both countries as below. In Finland, waste management and disposal methods are regulated by Nuclear Energy Act and national policy. Low and intermediate level wastes are disposed into the cave in bedrock at each nuclear power plant site. In Sweden, safety handling and disposal of waste are regulated by Act on Nuclear Activities. The disposal of low and intermediate level wastes has been operated under the seabed. This operation is carried out by a joint company which the nuclear companies have formed. In addition, we reported a site selection, burial depth and financial plan etc. in both nations.
Chijimatsu, Masakazu*; Fukudome, Kazuto*; Urano, Kazuhiko*; Imai, Hisashi*; Sasaki, Hajime*; Amemiya, Kiyoshi*
JNC TJ8400 2004-027, 87 Pages, 2005/02
JNC-TJ8400-2004-027.pdf:2.13MB
This study investigates the methodology for the engineered barriers performance confirmation. First of all the investigation about the monitoring concept in foreign countries were performed and the monitoring aiming was fixed at the performance confirmation of the engineered barriers. The monitoring item and the element of engineered barriers were set as followings, namely temperature, hydraulic pressure, water contents, pH, Eh and the chemistry of solutions. The indirect measuring method of items both providing the engineered barriers performance and varying with exhibition of performance from the rock around the engineered barriers is proposed for the engineered barriers performance confirmation monitoring.
Ishihara, Yoshinao*; Chijimatsu, Masakazu*; Amemiya, Kiyoshi*; Shiozaki, Isao*; Ito, Takaya*
JNC TJ8400 2004-015, 192 Pages, 2005/02
JNC-TJ8400-2004-015.pdf:1.98MB
In order to realize a coupling analysis in the near field of the geological disposal system, the coupling analysis code "COUPLYS (Coupling Analysis System)" on the Thermo-Hydro-Mechanical-Chemical (THMC) phenomena by THAMES, Dtransu and phreeqc, which are existing analysis code, is developed in this study.
Ishihara, Yoshinao*; Chijimatsu, Masakazu*; Amemiya, Kiyoshi*; Shiozaki, Isao*; Ito, Takaya*
JNC TJ8400 2004-004, 625 Pages, 2004/02
JNC-TJ8400-2004-004.pdf:7.37MB
In order to realize a coupling analysis in the near field of the geological disposal system, the coupling analysis code on the thermo-hydro-mechanical-chemical phenomena by THAMES, Dtransu and phreeqc, which are existing analysis code, is developed in this study. And we carried out the case analysis on the thermo-hydro-mechanical-chemical phenomena by this code.(1).Some supporting module, which includes transfer of dissolution concentration and total concentration (dissolution + precipitation concentration), was prepared as a functional expansion. And in order to treat de-gases and gases diffusion, accumulation and dilution phenomena, we have modified mass transport analysis code.(2).We have modified reactive transport module to treat ionic exchange, surface reaction and kinetic reaction in the each barrier.(3).We have prepared hydraulic conductivity module of buffer material depending on change of dry density due to chemical equilibrium (dissolution and precipitation of minerals), degradation of buffer material such as Ca-type bentonite and change of concentration of NaCl solutions. After THAMES, Dtransu, phreeqc and hydraulic conductivity module were installed in the COUPLYS, verification study was carried out to check basic function. And we have modified COUPLYS to control coupling process.(4).In order to confirm the applicability of the developed THMC analysis code, we have carried out case analysis on 1-dimensional and 3-dimensional model which including vitrified waste, over-pack, buffer material and rock in the HLW near-field.
Ishihara, Yoshinao*; Chijimatsu, Masakazu*; Neyama, Atsushi*; Tanaka, Yumiko*; Amemiya, Kiyoshi*; Shiozaki, Isao*; Ito, Takaya*
JNC TJ8400 2003-033, 118 Pages, 2003/02
JNC-TJ8400-2003-033.pdf:1.66MB
In order to realize a coupling analysis in the near field of the geological disposal system, the coupling analysis code on the thermo-hydro-mechanical-chemical phenomena by THAMES, Dtransu and phreeqe60, which are existing analysis code, is developed in this study. And we carried out the case analysis on the thermo-hydro-mechanical-chemical phenomena by this code.
Ishihara, Yoshinao*; Chijimatsu, Masakazu*; Neyama, Atsushi*; Tanaka, Yumiko*; Amemiya, Kiyoshi*; Shiozaki, Isao*; Ito, Takaya*
JNC TJ8400 2003-032, 237 Pages, 2003/02
In order to realize a coupling analysis in the near field of the geological disposal system, the coupling analysis code on the thermo-hydro-mechanical-chemical phenomena by THAMES, Dtransu and phreeqe60, which are existing analysis code, is developed in this study. And we carried out the case analysis on the thermo-hydro-mechanical-chemical phenomena by this code.
Moro, Yoshiji*; Amemiya, Kiyoshi*
JNC TJ7400 2005-051, 171 Pages, 2003/02
JNC-TJ7400-2005-051.pdf:13.35MB
In this report, the excavation influence analysis was executed imitating MIU by using crack progress analysis code FRACOD.
Chijimatsu, Masakazu*; Amemiya, Kiyoshi*
JNC TJ8400 2003-020, 53 Pages, 2003/01
JNC-TJ8400-2003-020.pdf:1.02MB
In order to achieve the geological disposal of radioactive waste in safe, it is necessary to ensure the stability of the engineered barrier system (EBS). One of the most important factors for the stability of the EBS is the emplacement technology of the EBS. It is considered that the stability of the EBS is secured by the properly emplacement based on the design requirement. In this research, the methods filling the gap between buffer and rock or buffer and over-pack were examined. Bentonite pellets were tested as the filling materials. To research the time-dependent phenomena of bentonite pellets after swelling, permeability tests were conducted with different period. Furthermore, to clarify the effect of test fluid, permeability test was conducted with synthetic seawater to compare the result with that of the test with distilled water. After emplacement of the engineered barrier system, it is expected that the near-field environment will be impacted by phenomena such as heat dissipation by conduction and other heat transfer mechanisms, infiltration of groundwater from the surrounding rock in to the engineered barrier system, stress imposed by the overburden pressure and generation of swelling pressure in the buffer due to water infiltration. In order to recognize and evaluate these coupled phenomena, it is necessary to make a confidence of the mathematical models and computer codes based on the information about the in-situ experiments regarding the engineered barrier system. In this research, technical investigations about the in-situ full-scale experiment (called Prototype Repository Project) in Aspo HRL facility by SKB of Sweden were performed. In order to evaluate the coupled phenomena in the engineered barrier, we use the new swelling model based on the theoretical approach. In this paper, we introduce the modeling approach and applicability about the new model.
Chijimatsu, Masakazu*; Amemiya, Kiyoshi*
JNC TJ8400 2003-019, 202 Pages, 2003/01
JNC-TJ8400-2003-019.pdf:4.56MB
In order to achieve the geological disposal of radioactive waste in safe, it is necessary to ensure the stability of the engineered barrier system (EBS). One of the most important factors for the stability of the EBS is the emplacement technology of the EBS. It is considered that the stability of the EBS is secured by the properly emplacement based on the design requirement. In this research, the methods filling the gap between buffer and rock or buffer and over-pack were examined. Bentonite pellets were tested as the filling materials. To research the time-dependent phenomena of bentonite pellets after swelling, permeability tests were conducted with different period. Furthermore, to clarify the effect of test fluid, permeability test was conducted with synthetic seawater to compare the result with that of the test with distilled water. After emplacement of the engineered barrier system, it is expected that the near-field environment will be impacted by phenomena such as heat dissipation by conduction and other heat transfer mechanisms, infiltration of groundwater from the surrounding rock in to the engineered barrier system, stress imposed by the overburden pressure and generation of swelling pressure in the buffer due to water infiltration. In order to recognize and evaluate these coupled phenomena, it is necessary to make a confidence of the mathematical models and computer codes based on the information about the in-situ experiments regarding the engineered barrier system. In this research, technical investigations about the in-situ full-scale experiment (called Prototype Repository Project) in Aspo HRL facility by SKB of Sweden were performed. In order to evaluate the coupled phenomena in the engineered barrier, we use the new swelling model based on the theoretical approach. In this paper, we introduce the modeling approach and applicability about the new model.
Chijimatsu, Masakazu*; Amemiya, Kiyoshi*
JNC TJ8400 2003-010, 190 Pages, 2003/01
JNC-TJ8400-2003-010.pdf:26.58MB
After emplacement of the engineered barrier system (EBS), it is expected that the near-field environment will be impacted by phenomena such as heat dissipation by conduction and other heat transfer mechanisms, infiltration of groundwater from the surrounding rock in to the engineered barrier system, stress imposed by the overburden pressure and generation of swelling pressure in the buffer due to water infiltration. In order to recognize and evaluate these coupled thermo-hydro-mechanical (THM) phenomena, it is necessary to make a confidence of the mathematical models and computer codes. Evaluating these coupled THM phenomena is important in order to clarify the initial transient behavior of the EBS within the near field. DECOVALEX project is an international co-operative project for the DEvelopment of COupled models and their VALidation against Experiments in nuclear waste isolation and it is significance to participate this project and to apply the code for the validation. Therefore, we tried to apply the developed numerical code against the subjects of DECOVALEX. We carried out the simulation against the Task1 (simulation of FEBEX in-situ full-scale experiment), Task 3 BMT1 (Bench Mark Test against the near field coupling phenomena) and Task3 BMT2 (Bench Mark Test against the up-scaling of fractured rock mass). This report shows the simulation results against these tasks.
Imai, Hisashi*; *; Yamashita, Ryo*; *; Amemiya, Kiyoshi*; Chijimatsu, Masakazu*
JNC TJ1400 2002-004, 357 Pages, 2002/03
Chijimatsu, Masakazu*; Amemiya, Kiyoshi*; Yamashita, Ryo*
JNC TJ8400 2002-024, 53 Pages, 2002/02
JNC-TJ8400-2002-024.pdf:4.81MB
no abstracts in English
Chijimatsu, Masakazu*; Amemiya, Kiyoshi*; Yamashita, Ryo*
JNC TJ8400 2002-023, 147 Pages, 2002/02
JNC-TJ8400-2002-023.pdf:10.91MB
In order to achieve the geological disposal of radioactive waste in safe, it is necessary to ensure the stability of the engineered barrier system (EBS). One of the most important factors for the stability of the EBS is the emplacement technology of the EBS. It is considered that the stability of the EBS is secured by the property emplacement based on the design requirement. In this research, the methods filling the gap between buffer and rock or buffer and over-pack were examined. Bentonite pellets were tested as the filling materials. To research the time-dependent phenomena of bentonite pellets after swelling, permeability tests were conducted with different period. Furthermore, to clarify the effect of test fluid, permeability test was conducted with synthetic seawater to compare the result with that of the test with distilled water. After emplacement of the engineered barrier system, it is expected that the near-field envilonment will be impacted by phenomena such as heat dissipation by conduction and other heat transfer mechanisms, infiltration of groundwater from the surrounding rock in to the engineered barrier system, stress imposed by the overburden pressure and generation of swelling pressure in the buffer due to water infiltration. In order to recognize and evaluate these coupled phenomena, it is necessary to make a confidence of the mathematical models and computer codes based on the information about the in-situ experiments regarding the engineered barrier system. In this research, technical investigations about the in-situ full-scale experiment (called Prototype Repository Project) in Aspo HRL facility by SKB of Sweden were performed.
Chijimatsu, Masakazu*; Amemiya, Kiyoshi*; Yamashita, Ryo*
JNC TJ8400 2002-022, 70 Pages, 2002/02
JNC-TJ8400-2002-022.pdf:5.66MB
no abstracts in English
Chijimatsu, Masakazu*; Amemiya, Kiyoshi*; Yamashita, Ryo*
JNC TJ8400 2002-021, 258 Pages, 2002/02
JNC-TJ8400-2002-021.pdf:8.82MB
After emplacement of the engineered barrier system (EBS), it is expected that the near-field environment will be impacted by phenomena such as heat dissipation by conduction and other heat transter mechanisms, infiltration of groundwater from the surrounding rock in to the engineered barrier system, stress imposed by the overburden pressure and generation of swelling pressure in the buffer due to water infiltation. In order to recognize and evaluate these coupled thermo-hydro-mechanical (THM) phenomena, it is necessary to make a confidence of the mathematical model and computer codes. Evaluating these coupled THM phenomena is important in order to clarify the initial transient behavior of the EBS within the near field. DECOVALEX project is an international co-opelative project for the DEvelopment of COupled models and their VALidation against EXperiments in nuclear waste isolation and it is significance to participate this project and to apply the code for the validation. Therefore, we tried to apply the developed numerical code against the subjects of DECOVALEX. In the above numerical code, swelling phenomenon is modeled as the function of water potential. However it does not evaluate the experiment results enough. Then, we try to apply the new model.
Chijimatsu, Masakazu*; Neyama, Atsushi*; Ishihara, Yoshinao*; Amemiya, Kiyoshi*; *; Iwata, Hiroshi*; Sagawa, Hiroshi*
JNC TJ8400 2002-004, 83 Pages, 2002/02
JNC-TJ8400-2002-004.pdf:0.91MB
In order to realize a coupling analysis in the near field of the geological disposal system, this study has been studied on the addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES) and preliminary coupling analysis by using development environmental tool (Diffpack) for numerical analysis. (1) In order to prepare the strategy on the addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES), we have studied on the requirement of THAMES-Transport and methodology of coupling analysis. After that we set out modification plan by the Eulerian-Lagrangian (EL) method. (2) Based on the document of modification plan, we have done addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES) and carried out verification analysis in order to confirm on the accuracy of THAMES-Transport. (3) In order to understand on the behavior of NaCl in the porewater under the coupled thermo-hydro-mechanical phenomena in the HLW engineered barrier system, we have calculated coupling phenomenon by using THAMES-Transport. Transportation and concentration phenomena of NaCl are calculated but precipitation of NaCl is not occurred under the analysis conditions in this report. (4) In order to confirm about feasibility of coupling analysis under the development environmental tool (Diffpack) for numerical analysis, we have carried out on the design work and writing program of the preliminary coupling system. In this study, we have adopted existing transport model (HYDROGEOCHEM) and geochemical model (phreeqe60) for preliminary coupling system. (5) In order to confirm program correctness of preliminary coupling system, we have carried out benchmarking analysis by using existing reactive-transport analysiscode (HYDROGEOCHEM). (6)We have been prepared short-range development plan based on through the modification study of THAMES and writing program of the preliminary coupling ...
Chijimatsu, Masakazu*; Neyama, Atsushi*; Ishihara, Yoshinao*; Amemiya, Kiyoshi*; *; Iwata, Hiroshi*
JNC TJ8400 2002-003, 155 Pages, 2002/02
JNC-TJ8400-2002-003.pdf:1.51MB
In order to realize a coupling analysis in the near field of the geological disposal system, this study has been studied on the addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES) and preliminary coupling analysis by using development environmental tool (Diffpack) for numerical analysis. (1)In order to prepare the strategy on the addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES), we have studied on the requirement of THAMES-Transport and methodology of coupling analysis. After that we set out modification plan by the Eulerian-Lagrangian (EL) method. (2)Based on the document of modification plan, we have done addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES) and carried out verification analysis in order to confirm on the accuracy of THAMES-Transport. (3)In order to understand on the behavior of NaCl in the porewater under the coupled thermo-hydro-mechanical phenomena in the HLW engineered barrier system, we have calculated coupling phenomenon by using THAMES-Transport. Transportation and concentration phenomena of NaCl are calculated but precipitation of NaCl is not occurred under the analysis conditions in this report. (4)In order to confirm about feasibility of coupling analysis under the development environmental tool (Diffpack) for numerical analysis, we have carried out on the design work and writing program of the preliminary coupling system. In this study, we have adopted existing transport model (HYDROGEOCHEM) and geochemical model (phreeqe60) for preliminary coupling system. (5)In order to confirm program correctness of preliminary coupling system, we have carried out benchmarking analysis by using existing reactive-transport analysiscode (HYDROGEOCHEM). (6)We have been prepared short-range development plan based on through the modification study of THAMES and writing program of the preliminary coupling ...
Imai, Hisashi*; Yamashita, Ryo*; Amemiya, Kiyoshi*; Shiozaki, Isao*
JNC TJ1410 2001-002, 318 Pages, 2001/08
Chijimatsu, Masakazu*; Amemiya, Kiyoshi*; Yamashita, Ryo*
JNC TJ8400 2001-021, 65 Pages, 2001/02
JNC-TJ8400-2001-021.pdf:5.74MB
no abstracts in English
