Safety and Facility Management Section, Tono Geoscience Center
JAEA-Review 2020-052, 116 Pages, 2021/03
This progress report presents an outline compilation of construction activities, primary tasks performed, construction progress and safety patrol report at the Mizunami Underground Research Laboratory Construction Work Part VIII. The outline of construction activities is a summary based on the scope of work planned the main activities are based on the Tono Geoscience Center weekly reports; and the construction progress is based on the planned and actual schedules. The actual performance of the construction work of MIU part VIII carried out from April 1, 2018 until May 15, 2020 is described in this report.
Onoe, Hironori; Kimura, Hitoshi*
JAEA-Research 2019-001, 57 Pages, 2019/08
In this study, predictive simulations were conducted in order to understand recovery behavior of groundwater environment during groundwater filling test and underground facility closure. As a result of predictive simulations of groundwater filling test, difference of groundwater environment changes around the closure test drift according to groundwater filling volume was confirmed quantitatively. As a result of the simulations, groundwater environment changes at 10 years after underground facility closure could be estimated. And, it was shown that up-corning of deep saline water through drift and shaft was occurred if hydraulic conductivity of backfill material is higher than host rock.
Iwatsuki, Teruki; Onoe, Hironori; Ishibashi, Masayuki; Ozaki, Yusuke; Wang, Y.*; Hadgu, T.*; Jove-Colon C. F.*; Kalinina, E.*; Hokr, M.*; Balvn, A.*; et al.
JAEA-Research 2018-018, 140 Pages, 2019/03
DECOVALEX-2019 Task C aims to develop modelling and prediction methods using numerical simulation based on the water-filling experiment to examine the post drift-closure environment recovery processes. In this intermediate report, the results of Step 1 (Modelling and prediction of environmental disturbance by CTD excavation) are summarized from each of the research teams (JAEA, Sandia National Laboratories, Technical University of Liberec). Groundwater inflow rates to the tunnel during the excavation, hydraulic drawdown, and variation of chlorine concentration at monitoring boreholes in the vicinity of the tunnel were chosen as comparison metrics for Step1 by mutual agreement amongst the research teams. It is likely to be possible to foresee the scales of inflow rate and hydraulic drawdown based on a data from the pilot borehole by current simulation techniques.
Geoscience Facility Construction Section, Tono Geoscience Center
JAEA-Review 2018-026, 92 Pages, 2019/02
This progress report presents an outline compilation of construction activities, primary tasks performed, construction progress and safety patrol report, in Fiscal Year 2016-2017. The outline of construction activities is a summary based on the scope of work planned in Fiscal Year 2016-2017: the main activities are based on the Tono Geoscience Center weekly reports; and the construction progress is based on the planned and actual schedules. Regarding the actual performance of the construction work of MIU part VII (March 16, 2016 -March 15, 2018) performance carried out from April 1, 2016 until March 15, 2018 is described in this report and the performance started from March 16, 2018 is supposed to be described in progress report of construction work of MIU part VIII.
Proceedings of 6th East Asia Forum on Radwaste Management Conference (EAFORM 2017) (Internet), 6 Pages, 2017/12
The Mizunami Underground Research Laboratory project is being pursued by the JAEA in the crystalline host rock at Mizunami City in Gifu Prefecture. The project proceeds in three overlapping phases, Surface-based investigation Phase (Phase I), Construction Phase (Phase II) and Operation Phase (III). During Phase I, a step-wise investigation was conducted by iterating investigation, interpretation, and assessment, thereby understanding of geologic environment was progressively and effectively improved with progress of investigation. During Phase II, we have evaluated adequacy of techniques for investigation, analysis and assessment of the deep geological environment established in the Phase I. For Phase III, three important issues were identified based on the latest results. Development of countermeasure technologies for reducing groundwater inflow, Development of modeling technologies for mass transport, Development of drift backfilling technologies.
Takayasu, Kentaro; Onuki, Kenji*; Kawamoto, Koji*; Takayama, Yusuke; Mikake, Shinichiro; Sato, Toshinori; Onoe, Hironori; Takeuchi, Ryuji
JAEA-Technology 2017-011, 61 Pages, 2017/06
The Groundwater REcovery Experiment in Tunnel (GREET) was put into effect as development of drift backfilling technologies. This test was conducted by making the Closure Test Drift (CTD) recovered with water after carrying out a plug around 40m distance from northern edge face of horizontal tunnel of depth 500m, for the purpose of investigation of recovering process of rock mass and groundwater under the influence of excavation of tunnel. This report presents the efforts of backfilling investigation using bentonite composite soil and execution of backfilling into borehole pits excavated in the CTD which were carried out in fiscal 2014 as a part of GREET, and succeeding observation results inside pits from September 2014 to March 2016.
Sato, Toshinori; Sasamoto, Hiroshi; Ishii, Eiichi; Matsuoka, Toshiyuki; Hayano, Akira; Miyakawa, Kazuya; Fujita, Tomo*; Tanai, Kenji; Nakayama, Masashi; Takeda, Masaki; et al.
JAEA-Research 2016-025, 313 Pages, 2017/03
The Horonobe Underground Research Laboratory (URL) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formations at Horonobe, northern Hokkaido. This report summarizes the results of the Phase II investigations carried out from April 2005 to June 2014 to a depth of 350m. Integration of work from different disciplines into a "geosynthesis" ensures that the Phase II goals have been successfully achieved and identifies key issues that need to made to be addressed in the Phase II investigations Efforts are made to summarize as many lessons learnt from the Phase II investigations and other technical achievements as possible to form a "knowledge base" that will reinforce the technical basis for both implementation and the formulation of safety regulations.
Geoscience Facility Construction Section, Tono Geoscience Center
JAEA-Review 2016-027, 190 Pages, 2017/02
This progress report presents an outline compilation of construction activities, primary tasks performed, construction progress and safety patrol report, in Fiscal Year 2014-2015. The outline of construction activities is a summary based on the scope of work planned in Fiscal Year 2014-2015: the main activities are based on the Tono Geoscience Center weekly reports; and the construction progress is based on the planned and actual schedules. Regarding the actual performance of the construction work of MIU part VI (March 16, 2014 -March 15, 2016) performance carried out from April 1, 2014 until March 15, 2016 is described in this report and the performance started from March 16, 2016 is supposed to be described in progress report of construction work of MIU part VII.
Construction Department; Tono Geoscience Center, Sector of Decommissioning and Radioactive Waste Management; Horonobe Underground Research Center, Sector of Decommissioning and Radioactive Waste Management
JAEA-Technology 2015-034, 411 Pages, 2016/03
This report presents the results of shaft and gallery excavation performed focusing on crystalline rock (Mizunami) and sedimentary rock (Horonobe) from the point of view of construction technologies applied and the information obtained at respective construction stages, which is required for construction designing Facility construction in general, its goal is to build the facilities and the general and accrual designs are made based on the specific construction plan, while the construction of shafts and research galleries is being conducted based on the research plan. This construction is performed in the deep underground where significant uncertainties exit, for instance, it is difficult to obtain the precision information from preliminary investigation, construction work is inextricability liked to the stepwise research, and this very long-term construction period is likely to be receiving restrictions concerning environmental and social interests. Therefore, there are a number of conditions can not to be predicted at the initial design stage. Timely and appropriate actions will be taken to deal with these particular conditions, such as changing on design due to the revision of the research and construction plan while conducting excavation construction. In the series of construction activities: from input (i.e. construction conditions) to completion of the construction under the particular conditions, we summarize the experiences obtained at respective construction stages as the important information to transfer the technology to the similar construction in the future. This report describes the general consideration and summary of chapters at the beginning, and introduces the construction activities performed at each rock series.
Hosoya, Shinichi*; Yamashita, Tadashi*; Iwatsuki, Teruki; Saegusa, Hiromitsu; Onoe, Hironori; Ishibashi, Masayuki
JAEA-Technology 2015-027, 128 Pages, 2016/01
The study for development of drift backfilling technologies is one of the critical issues in the Mizunami Underground Research Laboratory (MIU) project, and its purposes are to develop closure methodology and technology, and long-term monitoring technology, and to evaluate resilience of geological environment. To achieve the purposes, previous information from the case example of underground facility constructed in crystalline rock in Europe has been collected. In particular, the boundary conditions for the closure, geological characteristics, technical specifications, and method of monitoring have been focused. The information on the international project regarding drift closure test and development of monitoring technologies has also been collected. In addition, interviews were conducted to specialists who have experiences involving planning, construction management, monitoring, and safety assessment for the closure. Based on the collected information, concept and point of attention, which are regarding drift closure testing, and planning, execution management and monitoring on the closure of MIU, have been specified.
Hasegawa, Takashi; Kawamoto, Koji; Yamada, Nobuto; Onuki, Kenji; Omori, Kazuaki; Takeuchi, Ryuji; Iwatsuki, Teruki; Sato, Toshinori
JAEA-Technology 2015-011, 135 Pages, 2015/07
The geological, hydraulic and geochemical data such as rock mass classification, groundwater inflow points and the volume, water pressure, and hydraulic conductivity were obtained from boreholes (13MI3813MI44) in the -500m Access/Research Gallery-North of Mizunami Underground Research laboratory (MIU). In addition to data acquisition, monitoring systems were installed to observe hydrochemical changes in the groundwater, and rock strain during and after the groundwater recovery experiment.
Tanai, Kenji; Horita, M.*; *; Goke, Mitsuo*
JNC-TN8410 2001-026, 116 Pages, 2002/03
Earthquake resistance for the underground structure is higher than the ground structure. Therefore, the case of examining the earthquake resistance of underground structure was little. However, it carries out the research on the aseismic designing method of underground structure, since the tunnel was struck by Hyogo-ken Nanbu Earthquake, and it has obtained a much knowledge. However, an object of the most study was behavior at earthquake of the comparatively shallow underground structure in the alluvial plain board, and it not carry out the examination on behavior at earthquake of underground structure in the deep rock mass. In the meantime, underground disposal facility of the high level radioactive waste constructs in the deep underground, and it carries out the operation in these tunnels. In addition, it has made almost the general process of including from the construction start to the backfilling to be about 60 years (Japan Nuclear Fuel Cycle Development Institute, 1999). During these periods, it is necessary to also consider the earthquake resistance as underground structure from the viewpoint of the safety of facilities. Then, it extracted future problem as one of the improvement of the basis information for the decision of the safety standard and guideline of the country on earthquake-resistant design of the underground disposal facility, while it carried out investigation and arrangement of earthquake-resistant design cases, guidelines and analysis method on existing underground structure, etc.. And, the research item for the earthquake resistance assessment of underground structure as case study of the underground research laboratory.
; ; *; Hirose, Ikuro
JNC-TN7430 2000-001, 47 Pages, 2000/12
Long-term immersion tests of glass material at ambient temperature (about 18 C) for 10 years were performed in a gallery at the Tono mine in Japan, in order to assess durability of glass matelial contacted with natural groundwater. The gallery was constructed at a depth of 130 m below ground surface in the Toki Granite. Monolithic glass blocks with dimensions of 10 10 10 mm (cubic type) and of 25 mm in diameter and 8 mm in thickness (disk type: The wall of sample was covered by stainless steel of 1 mm thick.) were used for the tests. Both type of samples with and without clay were put in Teflon vessels, which have small holes on the wall, and inserted into boreholes excavated at the gallery floor. In addition to the immersion tests, static leaching test with cubic type glass and ground water was also performed at the gallery. The samples of each test were collected in time intervals of 6 months, 1 year, 2 years, 3 years and 10 years and were subjected to weight loss measurement and several surface analyses. The results were as follows: (1)Weight losses of each sample were proportional to time intervals. This result is attributable to constant dissolved silica concentration in the ground water during tests. (2)The weight losses of disk type glass were slightly larger than those of cubic type glass. This result is attributable to elemental release from internal cracks of disk type glass, instead of effect of stainless steel on the glass dissolution. (3)The weight losses for the tests with clay were slightly smaller than those for tests without clay. This result is attributable to higher concentration of dissolved silica in pore water of clay.
Sasao, Eiji; Okubo, Seisuke*
JNC-TN7450 2000-019, 42 Pages, 2000/11
no abstracts in English
; ; Shimizu, Kazuhiko; Miyahara, Kaname; ; Seo, Toshihiro; Fujita, Tomo
JNC-TN1410 2000-008, 100 Pages, 2000/10
no abstracts in English
; ; ; Saito, Hiroshi;
JNC-TN7410 2000-004, 16 Pages, 2000/04
Koide, Kaoru; Nakano, Katsushi; ; ; ; Saito, Hiroshi; Takeuchi, Shinji
JNC-TN7410 2000-001, 56 Pages, 2000/04
*; *; Morooka, Koichi*
JNC-TJ8400 2000-043, 171 Pages, 2000/03
This study is an object to collect and arrange data about the mass transfer path during a natural barrier system by grasping actual rock feature, in order to be useful for a performance assessment of a natural barrier system at geological disposal of HLW. An existence of permeability high large-scale faults extends a large influence over a performance assessment of geological disposal. With "The Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan" which Nuclear Cycle Development Institute (JNC) issued, it is as" A repository would be located at least 100 meters away from major faults and major fracture zones which could adversely affect the stability and performance of the repository" as a Reference Case concept model of a natural barrier system, Then, they are as "in the Reference Case, the transport path consists of the host rock and the downstream fault". It will not be easy to know the distribution of faults in the subsurface deep division without data acquired from many boreholes and underground laboratory. With this study, specific data on the large-scale faults and fracture zones has been collected and arranged by investigating in underground galleries and on the literatures of a post-operated mine site. Based on this result, a consideration on the principal transfer pass at a natural barrier system has been conducted. The contents conducted in this report is the follows. (1)investigation of literature about data of fracture, shear zone, and geology, (2)field investigation of fracture and shear zone in the rock, (3)arrangement of these results, (4)modeling of the major water conductive feature, and (5)evaluation of an assumption which has been introduced in the Second Progress Report issued by JNC.
*; *; Okutsu, Kazuo*; Yamamoto, Takuya*; Amemiya, Kiyoshi*
JNC-TJ8400 2000-022, 303 Pages, 2000/02
This report gives supplementary information and discussions on issues of the high-level waste geological disposal study. The following subjects are discussed ; (1)Evaluation of the effects of coefficient of lateral pressure to the specifications of disposal facilities (2)Functional development of remote operational machinery (3)Arrangement of basic data on cost estimation for disposal (4)Understanding of engineering countermeasures to potential phenomena deep under the ground (5)Selection of construction technologies (6)Establishment of the disposal concept under the coasts. For the coefficient of lateral pressure equal to 2, the cross section of disposal drift, the disposal drift spacing, the waste package pitch in the disposal drift and the specification of supporting system are designed. They are compared with those for the case of coefficient of lateral pressure equal to 1. In the case of coefficient of lateral pressure equal to 2, total length of drifts is 1.5 times, and total excavation volume is 1.8 times larger than later case. For the sealing, transportation and emplacement equipment for waste, technology of the fundamental function, remote operation, accidental events and countermeasures are discussed. The plan for developments on those items is proposed. The item of the cost for the construction, operation, and backfilling are discussed. The surface facilities, and, worker arrangement plan are proposed. For the potential phenomena encountered deep under the ground, the countermeasures are investigated form the construction experience, and the future research subjects are discussed for the underground research laboratory. For the construction technologies, the experience of construction management for the tunnel is investigated, and, the research subjects are proposed. For the disposal concept under coasts, rock condition, design condition, construction management, and quality control are compared with the disposal concept under the ground. The ...
*; *; *; *
JNC-TJ7440 2000-002, 74 Pages, 2000/02
no abstracts in English