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Makino, Hitoshi; Semba, Takeshi; Shibata, Masahiro
NEA/RWM/R(2018)7 (Internet), p.315 - 322, 2022/11
This presentation summarize challenge on development of an advanced KMS by JAEA including the background to this initiative, the basic approach selected, a developed prototype of the JAEA KMS, and challenges and practical issues for introduction and also sustainable maintenance of the JAEA KMS.
Deguchi, Akira*; Umeki, Hiroyuki*; Ueda, Hiroyoshi*; Miyamoto, Yoichi; Shibata, Masahiro; Naito, Morimasa; Tanaka, Toshihiko*
LBNL-1006984 (Internet), p.12_1 - 12_22, 2016/12
The H12 report demonstrated the feasibility of safe and technically reliable geological disposal in 1999. The Government of Japan re-evaluated the geological disposal program in terms of technical feasibility based on state-of-the-art geosciences and implementation process, because more than 10 years have passed from H12 and the Great Earthquake and nuclear accident have increased public concern regarding nuclear issues and natural hazards to cause accidents at nuclear facilities. Following the re-evaluation, the Government concluded further to promote geological disposal program, and thus the Basic Policy for Final Disposal was revised in 2015 including a new approach to siting process with identification of "Scientifically Preferable Areas". NUMO and relevant research organizations such as JAEA have been carrying out R and D activities to increase technical reliability for geological disposal. NUMO has started to develop a generic safety case.
Goto, Takahiro*; Mitsui, Seiichiro; Takase, Hiroyasu*; Kurosawa, Susumu*; Inagaki, Manabu*; Shibata, Masahiro; Ishiguro, Katsuhiko*
MRS Advances (Internet), 1(63-64), p.4239 - 4245, 2016/00
NUMO and JAEA have conducted a joint research since FY2011, which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage for deep geological disposal of radioactive waste. As a part of this joint research, we have been developing glass dissolution models which consider various processes in EBS, such as precipitation of Fe-silicates associated with iron overpack corrosion, and Si transport through corrosion products in the cracked overpack. The objectives of the modeling work are to evaluate relative importance of relevant processes and to identify further R&D issues towards development of a convincing safety case. Sensitivity analyses suggested that predicted glass dissolution time ranges from 1
10
to 110
years or more due to uncertainties in the current understanding of the key processes, namely precipitation of Fe-silicates and transport characteristics of the altered glass layer.
Shibata, Masahiro; Kamei, Gento
Nihon Genshiryoku Gakkai-Shi ATOMO
, 57(4), p.271 - 275, 2015/04
no abstracts in English
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.
JAEA-Research 2014-030, 457 Pages, 2015/03
JAEA-Research-2014-030.pdf:199.23MB
JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.
Ebashi, Takeshi; Kawamura, Makoto*; Inagaki, Manabu*; Koo, Shigeru*; Shibata, Masahiro; Itazu, Toru; Nakajima, Kunihiko*; Miyahara, Kaname; Apted, M. J.*
Materials Research Society Symposium Proceedings, Vol.1665, p.39 - 45, 2014/07
In Japan, the likelihood of uplift/erosion on repository performance and waste isolation can be typically greatly reduced or excluded by careful siting, however, the inability to completely exclude the uplift/erosion scenario may require an analysis of the consequences of such a scenario. For this purpose, an assessment approach has been developed to more realistically treat the effect of uplift/erosion for a hypothetical repository located in sedimentary host rock. A key advantage to this approach is the extrapolation of the geohistory of modern analogue sites to develop credible initial inputs for future volunteer sites that may be poorly characterized at the initial stages of site investigation. In addition, the approach provides a systematic basis for bounding the range of possible evolution in thermal-hydrological-mechanical-chemical conditions of a repository experiencing different uplift/ erosion rates.
Hatanaka, Koichiro; Shibata, Masahiro
Tekisuto "Kakunenryo Saikuru" (Internet), 6 Pages, 2014/06
no abstracts in English
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Hayano, Akira; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.
JAEA-Research 2013-037, 455 Pages, 2013/12
JAEA-Research-2013-037.pdf:42.0MB
Following FY2011, JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, the tree diagram of methodology of groundwater travel time has been extended for crystalline rock, in addition, tree diagram for sedimentary rock newly has been organized. With regard to (2) study on scenario development, the existing approach has been improved in terms of a practical task, and applied and tested for near field focusing on the buffer. In addition, the uncertainty of some important processes and its impact on safety functions are discussed though analysis. With regard to (3) study on setting radionuclide migration parameters, the approaches for parameter setting have been developed for sorption for rocks and solubility, and applied and tested through parameter setting exercises for key radionuclides.
Shimemoto, Hidenori; Yamaguchi, Masaaki; Wakasugi, Keiichiro; Shibata, Masahiro
JAEA-Research 2013-012, 35 Pages, 2013/10
JAEA-Research-2013-012.pdf:8.16MB
In this study, we focus on uplift and erosion and climatic and sea-level changes among natural phenomena and pick up fluvial erosion is main and means large velocity between different type of erosion in Japan, and developed conceptual modeling of geomorphic change due to fluvial erosion with respect to fluvial erosion and sedimentation system, to evaluate the potential impact of exposure case of high level radioactive waste to land surface. Conceptual modeling of geomorphic change caused by fluvial erosion is developed with riverhead and downriver, such catchment areas are not treated until now, by conceptualization of geomorphic change on river due to uplift and denudation and climatic and sea-level changes for about last hundred and twenty thousand years. Furthermore, we analysis the depth and width of deepening and lateral erosion around river channel using the data of alluvium and show an example of the setup method concerning dimension on conceptual model to estimate the erosion volume contribute to the evaluation as to high level radioactive waste exposure process to land surface. We illustrate by an example the dimension as to valley within the central Japanese mountains using DEM data on conceptual model at riverhead. We develop conceptual modeling of geomorphic change on the basis of the feature on fluvial erosion in Japan and set basic intelligence to evaluate the potential impact of repository exposure to land surface caused by fluvial erosion, based on above study.
Wakasugi, Keiichiro; Nakajima, Kunihiko*; Shimemoto, Hidenori; Shibata, Masahiro; Yamaguchi, Masaaki
Proceedings of 21st International Conference on Nuclear Engineering (ICONE-21) (DVD-ROM), 9 Pages, 2013/07
In Japan, uplift and erosion scenarios must be analysed since this natural phenomena would be inevitable at most sites in Japan. It's increasingly important to enhance the confidence of the assessment for the uplift and erosion scenarios, as no assessment cut-off times have yet been defined. In this context, this study carried out bounding analysis to find out parameter conditions to satisfy hypothetical dose criteria. The results show that there are no cases that satisfy 10 microSv/y. However, all cases are below 300 microSv/y. The discussion also implies that to accelerate the release from the EBS for minimising the dose in later phase is inadequate and ineffective at all, due to multiple barriers and multiple safety functions. In principal, the influence of uplift and erosion should be reduced by appropriate site selection and design as much as possible to ensure the sufficient nuclides decay while the repository is staying at the deep underground.
Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Hayano, Akira; Mitsui, Seiichiro; Taniguchi, Naoki; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.
JAEA-Research 2012-032, 298 Pages, 2012/09
JAEA-Research-2012-032.pdf:33.68MB
JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation phase. The topics and the conducted research are follows; (1) Study on selection of host rock: in terms of hydraulic properties, items for assessing rock property, and assessment methodology of groundwater travel time has been organized with interaction from site investigation. (2) Study on development of scenario: the existing approach has been embodied, in addition, the phenomenological understanding regarding dissolution of and nuclide release from vitrified waste, corrosion of the overpack, long-term performance of the buffer are summarized. (3) Study on setting nuclide migration parameters: the approach for parameter setting has been improved for sorption and diffusion coefficient of buffer/rock, and applied and tested for parameter setting of key radionuclides. (4) Study on ensuring quality of knowledge: framework for ensuring quality of knowledge has been studied and examined aimed at the likely disposal facility condition.
Inagaki, Manabu*; Tanaka, Tatsuya*; Hashimoto, Shuji*; Maekawa, Keisuke; Shibata, Masahiro
JAEA-Research 2011-056, 37 Pages, 2012/03
JAEA-Research-2011-056.pdf:8.64MB
In Japan, a step-wise approach is applied in the site selection process for the geologic disposal site. Preliminary surface-based investigations will be followed by detailed investigations. The basic repository concept, including underground design and layout, will be discussed at the end of surface-based investigations. The repository concept will depend on the spatial extent of the candidate rock formation(s) and their barrier performance. However, information obtained from the surface is limited and includes uncertainties. It is thus important to assess host rock performance considering uncertainties. In this study, methodology for evaluation of geological conditions has been developed that focuses on determining the usable volume of host rock with specific performance characteristics. Initially, multiple performance indices have been discussed and defined from the viewpoint of barrier performance. Then the evaluation procedure is illustrated by using the dataset obtained from the Horonobe Underground Research Laboratory Project. Finally the proposed procedure is reviewed and future challenges are extracted.
Wakasugi, Keiichiro; Koo, Shigeru*; Shibata, Masahiro
JAEA-Research 2011-006, 31 Pages, 2011/06
JAEA-Research-2011-006.pdf:2.37MB
Although confirmation of the long-term safety of the constructed geological disposal system has been conducted by using scenario, model and data according to the internationally agreed methodology, there were a few researches that focused on individual safety functions and their relationships. This is because multiple safety functions are a fundamental concept for ensuring the safety of the geological disposal, and the long-term safety is accomplished by the whole system. Therefore, we developed a methodology to identify performance of the individual safety functions and their relationships considering the characteristic of the multiple safety functions, and examined the safety functions in the engineered barrier system based on this methodology. The results from this study are useful for constructing design requirements for the system components of the geological disposal as well as developing repository concept.
Miyahara, Kaname; Tachi, Yukio; Kitamura, Akira; Mitsui, Seiichiro; Sawada, Atsushi; Shibata, Masahiro; Neall, F.*; McKinley, I. G.*
Proceedings of 2011 International High-Level Radioactive Waste Management Conference (IHLRWMC 2011) (CD-ROM), p.292 - 298, 2011/04
As the Japanese deep geological disposal programme prepares for milestones at which volunteer sites need to be compared, it is critical that any supporting post-closure safety assessment is done as realistically as possible. Because of the subtle system understanding needed to integrate diverse theoretical, laboratory, field and analogue models, data and observations into the high-level parameters that are incorporated into performance assessment models, normal QA procedures tend to fail completely. This problem is discussed further in this paper and solutions outlined, which build on recent developments of supporting knowledge engineering tools.
Fujita, Tomoo; Taniguchi, Naoki; Matsui, Hiroya; Tanai, Kenji; Maekawa, Keisuke; Sawada, Atsushi; Makino, Hitoshi; Sasamoto, Hiroshi; Yoshikawa, Hideki; Shibata, Masahiro; et al.
JAEA-Research 2011-001, 193 Pages, 2011/03
JAEA-Research-2011-001.pdf:5.23MB
This report summarizes the progress of research and development on geological disposal during the surface-based investigation phase (2001-2005) in the Horonobe Underground Research Laboratory project, of which aims are to apply the design methods of geological disposal and mass transport analysis to actual geological conditions obtained from the surface-based investigations in the Horonobe Underground Research Laboratory project as an example of actual geological environment.
Umeki, Hiroyuki; Hioki, Kazumasa; Osawa, Hideaki; Fujita, Tomoo; Shibata, Masahiro; Makino, Hitoshi; Iwatsuki, Teruki; Takeuchi, Shinji; Ishimaru, Tsuneari
JAEA-Review 2010-073, 255 Pages, 2011/02
JAEA-Review-2010-073.pdf:4.19MB
The Japan Atomic Energy Agency (JAEA) has been performing research and development on geological disposal technology of high level radioactive waste. At the end of fiscal year 2009, the Geological Isolation Research and Development Directorate of JAEA made publicly available the "CoolRep H22", which is a web-based report that summarizes the R&D results, on its website. This document reports the contents of CoolRep H22.
Kawamura, Makoto; Makino, Hitoshi; Sasao, Eiji; Niizato, Tadafumi; Yasue, Kenichi; Asamori, Koichi; Umeda, Koji; Ishimaru, Tsuneari; Osawa, Hideaki; Ebashi, Takeshi; et al.
JAEA-Research 2010-027, 85 Pages, 2010/09
JAEA-Research-2010-027.pdf:9.37MB
Japan Atomic Energy Agency (JAEA) have developed a formal evaluation method to assess the potential impacts of natural phenomena (earthquakes and faulting; volcanism; uplift, subsidence, denudation and sedimentation; climatic and sea-level changes) on a high level radioactive waste (HLW) disposal system for the purpose of maintenance of evaluation method for potential impacts of natural phenomena within more realistic view. In this report, we developed a framework as a part of the total system performance assessment for two purposes: the first one is quantification of relationship of characteristic of natural phenomena between geological environmental conditions (T-H-M-C-G), and the other one is quantification of relationship of T-H-M-C-G condition between parameters of performance assessment. We tried to apply the framework to all natural phenomena to confirm the effectiveness of the framework. On the other hand, we applied an argument-diagram that was developed one of the methods of the knowledge management to elicit future tasks. As a result, to apply the framework, we could show that information integration could carry out efficiently, and information integration was attained by the common framework by combining information on geohistory and existing information of natural phenomena and geological environmental conditions as modern-analogue. We could show that suitable scenarios might be chosen by information integration. Furthermore, we were able to elicit future tasks to this study by applying the argument-diagram.
Yui, Mikazu; Ishikawa, Hirohisa; Watanabe, Atsuo*; Yoshino, Kyoji*; Umeki, Hiroyuki; Hioki, Kazumasa; Naito, Morimasa; Seo, Toshihiro; Makino, Hitoshi; Oda, Chie; et al.
JAEA-Research 2010-015, 106 Pages, 2010/05
JAEA-Research-2010-015.pdf:13.58MB
This report summarizes the activity of Phase I of Waste Management Working Group of the United States - Japan Joint Nuclear Energy Action Plan started in 2007. The working group focused on consolidation of the existing technical basis between the U.S. and Japan and the joint development of a plan for future collaborative activities. Firstly, the political/regulatory frameworks related to nuclear fuel cycles in both countries were reviewed. The various advanced fuel cycle scenarios in both countries were surveyed and summarized. Secondly, the waste management/disposal system optimization was discussed. Repository system concepts for the various classifications of nuclear waste were reviewed and summarized, then disposal system optimization processes and techniques were reviewed, and factors to consider in future repository design optimization activities were also discussed. Finally the potential collaboration areas and activities related to the optimization problem were extracted.
Kitamura, Akira; Shibata, Masahiro; Yamaguchi, Tetsuji; Iida, Yoshihisa; Yui, Mikazu
JAEA-Technology 2009-074, 48 Pages, 2010/03
JAEA-Technology-2009-074.pdf:7.33MB
Investigations on systematics of thermodynamic data were performed for performance assessment of geological disposal of high-level and TRU waste. Correlation between standard free energy of formation and standard enthalpy of formation was investigated, and it was shown that estimation of the standard enthalpy of formation from the standard free energy of formation was possible using the correlation. Three models on systematics of formation constant of actinides were compared and the best model was proposed. It was shown that estimation of formation constant for unpublished species was possible using the model. Furthermore, two models for estimation of activity coefficient which was required to estimate solubility of elements of interest and the estimated activity coefficient were compared. It was expected that the obtained results were useful for the performance assessment of geological disposal.
Ebashi, Takeshi; Kawamura, Makoto; Inagaki, Manabu; Koo, Shigeru*; Shibata, Masahiro; Itazu, Toru; Nakajima, Kunihiko*; Miyahara, Kaname
JAEA-Research 2008-117, 36 Pages, 2009/03
JAEA-Research-2008-117.pdf:3.18MB
It is considered that it is possible to avoid the effect of the uplift and denudation process on geological disposal system by siting and a repository design. However, since the uplift/denudation continues far into the future, it is important to enhance the confidence of the methodology to evaluate such an effect, based on the understanding of geohistorical information and potential impact on the disposal system. This paper presents an evolution pattern of the geological environment and the influence analysis in terms of system performance affected by the uplift and denudation process based on the relevant conceptual models for groundwater scenarios of the disposal system for a hypothetical sedimentary rock. As a result, it is indicated that the conceptual model is capable to identify a specific combination of patterns of system evolution of the geological environment in terms of features on the uplift and denudation process, and also provides technical basis for setting up parameters of nuclide migration model and the subsequent influence analysis. Consequently, it is also indicated that the evaluation methodology applied in this study is valuable to evaluate the uplift/denudation phenomena with specific geological environment, and the results obtained by the analysis could be valuable information for site investigation and/or the prediction of a future change trend for the uplift/denudation.
