Results of environmental impact investigations as part of environmental monitoring investigation in backfilling of shafts and tunnels of Mizunami Underground Research Laboratory (2022)

Takeuchi, Ryuji; Nishio, Kazuhisa*; Kokubu, Yoko

JAEA-Data/Code 2023-013, 74 Pages, 2024/01

JAEA-Data-Code-2023-013.pdf:4.2MB

The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the environmental monitoring investigation to confirm the environmental impacts associated with the backfilling of shafts and tunnels at the Mizunami Underground Research Laboratory (MIU). This report summarizes the results of the environmental impact investigations conducted as part of the environmental monitoring investigation around the MIU Site in FY2022, which include groundwater level measurement in wells, river flow rate measurement, water analysis of Hazama river, noise and vibration surveys, and soil survey.

Results of environmental impact investigations as part of environmental monitoring investigation in backfilling of shafts and tunnels of Mizunami Underground Research Laboratory (2020-2021)

Takeuchi, Ryuji; Nishio, Kazuhisa*; Hanamuro, Takahiro; Kokubu, Yoko

JAEA-Data/Code 2022-010, 110 Pages, 2023/03

JAEA-Data-Code-2022-010.pdf:6.2MB

The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the environmental monitoring investigation to confirm the environmental impacts associated with the backfilling of shafts and tunnels at the Mizunami Underground Research Laboratory (MIU). This report summarizes the results of environmental impact investigations conducted as part of the environmental monitoring investigation around the MIU Site from FY2020 to FY2021, which include groundwater level measurement in wells, river flow rate measurement, water analysis of Hazama river, noise and vibration surveys, and soil survey.

Demonstration of the groundwater observation network system in backfilled underground facility

Murakami, Hiroaki; Takeuchi, Ryuji; Iwatsuki, Teruki

JAEA-Technology 2022-022, 34 Pages, 2022/10

JAEA-Technology-2022-022.pdf:3.47MB

Japan Atomic Energy Agency (JAEA) has been conducting the hydro-pressure and hydrochemical monitoring for more than two decades to understand the hydrochemical disturbance due to the excavation of tunnels at Mizunami Underground Research Laboratory (MIU). To understand the environmental influence due to the backfilling of research tunnels that started in 2019, environmental monitoring of groundwater has been performed and recovery status of groundwater is being confirmed. In order to observe the deep-groundwater environment from the ground, the groundwater pressure monitoring and sampling, which have been performed in the research tunnel, are to be performed from the ground. However, backfilling of a large-scale underground facilities such as MIU is globally unprecedented, thus it was necessary to develop a new observation system. Accordingly, we developed a new observation network to observe the environment around the research tunnels of the MIU. This system enables monitoring of groundwater pressure and water sampling of the backfilled tunnel from the ground while utilizing the existing-monitoring system installed in the tunnels. Accordingly, we demonstrated its technology through the environmental monitoring of groundwater. The results of the environmental monitoring and the existing groundwater data of MIU indicate that this system is able to monitor the groundwater environment in the backfilled tunnels.

Excavation of shafts and research galleries at the Mizunami Underground Research Laboratory (Construction work of MIU Part VIII); Construction progress report

Safety and Facility Management Section, Tono Geoscience Center

JAEA-Review 2020-052, 116 Pages, 2021/03

JAEA-Review-2020-052.pdf:12.81MB

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.

Data of long term hydro-pressure monitoring on Mizunami Underground Research Laboratory Project for fiscal year 2017-2019

Onoe, Hironori; Takeuchi, Ryuji

JAEA-Data/Code 2020-010, 112 Pages, 2020/10

JAEA-Data-Code-2020-010.pdf:6.22MB
JAEA-Data-Code-2020-010-appendix1(DVD-ROM).zip:169.12MB
JAEA-Data-Code-2020-010-appendix2(DVD-ROM).zip:338.45MB
JAEA-Data-Code-2020-010-appendix3(DVD-ROM).zip:448.05MB

The Mizunami Underground Research Laboratory (MIU) Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), the project is being carried out under the Phase III. The main goals of the MIU Project from Phase I to Phase III are: to establish techniques for investigation, analysis and assessment of the deep geological environment, and to develop a base of engineering for deep underground application. One of the Phase III goals is to construct geological environment models and grasp deep geological changes when expanding the research gallery by research and investigations using research galleries. The long term hydro-pressure monitoring has been continued to achieve the Phase III goals. Furthermore, these monitoring were ceased at the end of FY2019 due to the completion of the MIU project. This report describes the results of the long term hydro-pressure monitoring from April 2017 to March 2020.

Result of seismic motion observation from ground surface to 500m depth at Mizunami Underground Research Laboratory and its detailed analysis

Matsui, Hiroya; Watanabe, Kazuhiko*; Mikake, Shinichiro; Niimi, Katsuyuki*; Kobayashi, Shinji*; Toguri, Satohito*

Dai-47-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (Internet), p.293 - 298, 2020/01

Japan Atomic Energy Agency has been observed seismic motions induced by earthquakes, at ground surface, galleries at 100m, 300m and 500m depth of Mizunami underground research laboratory for over 10 years. The results suggested that the amplitude of the seismic motion decreases with depth as the previous study on crystalline rock at Kamaishi mine indicated. Detailed analysis on the observed seismic motions shows that the Fourier amplitude and the phase difference of the earthquake occurred near epicenter correspond with the one calculated by one-dimensional multiple reflection theory.

The Regional-scale 3D geological model in the Horonobe Underground Research Laboratory Project

Sakai, Toshihiro; Matsuoka, Toshiyuki

JAEA-Data/Code 2019-007, 29 Pages, 2019/09

JAEA-Data-Code-2019-007.pdf:53.07MB
JAEA-Data-Code-2019-007-appendix(CD-ROM).zip:340.04MB

Japan Atomic Energy Agency is performing the Horonobe Underground Research Laboratory Project, which includes a scientific study of the deep geological environment as a basis of research and development for the geological disposal of high level radioactive wastes, in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in the sedimentary rock. This report summarize numerical data of 3D geological model in regional-scale constructed by Maptek Vulcan.

Study of hydrogeology in the Mizunami Underground Research Laboratory Project; Numerical prediction of recovery behavior of groundwater environment during groundwater filling test and underground facility closure

Onoe, Hironori; Kimura, Hitoshi*

JAEA-Research 2019-001, 57 Pages, 2019/08

JAEA-Research-2019-001.pdf:10.03MB

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.

Horonobe Underground Research Laboratory Project; Investigation program for the 2018 fiscal year

Hanamuro, Takahiro

JAEA-Review 2018-011, 20 Pages, 2018/08

JAEA-Review-2018-011.pdf:2.77MB

As part of the research and development program on geological disposal of high-level radioactive waste (HLW), the Horonobe Underground Research Center, a division of the Japan Atomic Energy Agency (JAEA), is implementing the Horonobe Underground Research Laboratory Project (Horonobe URL Project) with the aim at investigating sedimentary rock formations. According to the research plan described in the 3rd Mid- and Long-term Plan of JAEA, according to the Horonobe URL Project, "Near-field performance study", "Demonstration of repository design option", and "Verification of crustal-movement buffering capacity of sedimentary rocks" are the top priority issues, and schedule for finishing the project and backfill plan will be decides by the end of 2019 Fiscal Year. The Horonobe URL Project is planned to extend over a period of about 20 years. This report summarizes the investigation program for the 2018 fiscal year (2018/2019).

The Mizunami Underground Research Laboratory

Onoe, Hironori

Keisan Kogaku, 23(2), p.3751 - 3752, 2018/04

In this paper, outline and current status of Mizunami Underground Research Laboratory, which is constructed by Tono Geoscience Center of Japan Atomic Energy Agency, in the Mizunami city, Gifu is introduced.