Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2005

Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Yoshida, Haruo*; et al.

JAEA-Review 2008-073, 99 Pages, 2009/03

JAEA-Review-2008-073-1.pdf:37.33MB
JAEA-Review-2008-073-2.pdf:37.16MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2005 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.

Hydrogeological investigations of surface-based investigation phase of Horonobe URL project

Kurikami, Hiroshi; Takeuchi, Ryuji; Yabuuchi, Satoshi; Seno, Shoji*; Tomura, Goji; Shibano, Kazunori; Hara, Minoru; Kunimaru, Takanori

Doboku Gakkai Rombunshu, C, 64(3), p.680 - 695, 2008/09

https://doi.org/10.2208/jscejc.64.680

Japan Atomic Energy Agency has been conducting the Horonobe Underground Research Laboratory (URL) project in Horonobe, Hokkaido, as a part of the research and development program on geological disposal of high-level radioactive waste. This paper shows the results of hydrogeological investigations in the surface-based investigation phase of the project. Hydrological and meteorological investigations show that the infiltration rates of the drainage basins varies and that the infiltration rate depends on the flora and the topography. The hydraulic tests using the deep boreholes reveals that hydraulic conductivity of the scale of a few decameters to a hundred meter varies widely and decreases with depth in the same formation, while the laboratory hydraulic tests suggest that hydraulic conductivity of the intact rock is influenced by the stress history. The hydraulic tests and the long-term monitorings of hydraulic pressure clarify relatively high pressure in the deep underground. Furthermore, groundwater flow analysis shows that the groundwater in and around the URL area flows regionally from the east to the west and depends locally on the geography and geology.

Long-term groundwater pressure monitoring in deep boreholes in the Horonobe Underground Research Laboratory Project

Yabuuchi, Satoshi; Kurikami, Hiroshi; Seno, Shoji*; Hara, Minoru; Kunimaru, Takanori; Takeuchi, Ryuji

JAEA-Research 2006-056, 32 Pages, 2006/09

JAEA-Research-2006-056.pdf:1.87MB

Long-term groundwater pressure monitoring has been performed in HDB-1,2,3,6,7 and HDB-8 boreholes in the Horonobe Underground Research Laboratory Project. Groundwater pressure in many levels in the boreholes shows an almost steady state at present, however it is still recovering since the beginning of the observation in some levels. Relatively high groundwater pressure is observed in HDB-2 borehole, about 7km away from the URL area. According to the groundwater pressure monitoring in deep boreholes so far, it is inferred that hydraulic head becomes higher with the increase of the depth and hydraulic head in the east is higher than in the west around the URL area. Through the groundwater monitoring, performance of the long-term groundwater monitoring systems could be examined and some problems of the parts could also be found.

Groundwater Flow Analysis of Horonobe Underground Research Laboratory Project

Kurikami, Hiroshi; Takeuchi, Ryuji; Seno, Shoji

JNC TN5400 2005-003, 97 Pages, 2005/07

JNC-TN5400-2005-003.pdf:22.19MB

This report shows the process and the result of the research on the hydrogeological modeling and groundwater flow (GW) analyses of Horonobe Underground Research Laboratory(URL) Project until fiscal year 2004. In the report, Surface-based Investigation (Phase I) of the project was divided into two phases; the investigation phase based on literature review and the borehole investigation phase. In the investigation phase based on literature review, the sensitivity analyses were carried out with the hydrogeological model built based on the considerable information from the literature review. The results showed that the sensitivities of recharge rate and hydraulic conductivity of the surface layer on hydraulic head and those of hydraulic conductivities of both Wakkanai formation and Koetoi formation on GW migration time were high. The results also showed that the GW flow system in and around the URL area was governed by the Shimzu river and Penke-ebekorobetsu river in the shallower zone (local GW flow system) and the Teshio river in the deeper zone (regional GW flow system). "Regional scale" analytical domain was defined based on the results. In the borehole investigation phase, the results of both the in-situ hydraulic tests and the laboratory hydraulic tests were summarized as follows: *The deeper it was, the lower the hydraulic conductivity was in the same layer, especially in Wakkanai formation. *The hydraulic conductivity of the upper layer was lower than that of the lower layer in the same depth. *The distribution of hydraulic conductivity was strongly related to that of fracture zone. The GW flow analyses based on newly developed geological model and the results of the hydraulic tests described above were performed. The GW flow analyses were verified by comparing with the measured hydraulic pressures in the boreholes. Besides, the behavior of saline GW was examined. Furthermore, the excavation of the URL shafts and tunnels was simulated. From the results, ...

Updating hydrogeology model of the Mizunami Underground Research Laboratory (MIU) using disturbance during shaft sinking, 1; Current status of construction phase investigations at the MIU

Semba, Takeshi; Uchida, Masahiro; Hama, Katsuhiro; Tsuruta, Tadahiko; Amano, Kenji; Takeuchi, Ryuji; Saegusa, Hiromitsu; Seno, Yasuhiro

no journal, , 

no abstracts in English

Overview of the final report on the surface-based investigation (Phase I) at the Mizunami Underground Laboratory project, 6; Techniques/methods for investigation and assessment of geological environment

Seno, Yasuhiro; Saegusa, Hiromitsu; Amano, Kenji; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Takeuchi, Ryuji; Mizuno, Takashi; Uchida, Masahiro

no journal, , 

no abstracts in English

Overview of the surface-based investigation phase (Phase I) at the Mizunami Underground Laboratory project, 1; Concept of the phase I investigation phase

Semba, Takeshi; Saegusa, Hiromitsu; Hama, Katsuhiro; Tsuruta, Tadahiko; Amano, Kenji; Takeuchi, Ryuji; Seno, Yasuhiro; Uchida, Masahiro

no journal, , 

no abstracts in English

Structural study of UPD Bi/Au(111) electrode surface in ionic liquid using in-situ surface X-ray scattering

Seno, Ryu; Tamura, Kazuhisa; Nishihata, Yasuo; Mizuki, Junichiro; Sakaue, Kiyoshi*

no journal, , 

The electrodeposited Bi/Au(111) surface structure in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([BMIM]TFSA) was investigated using surface X-ray scattering (SXS). The X-ray reflectivity analysis showed that the distance between the electrodeposited Bi layer and the most outer Au surface layer was 2.47 and it agreed that Bi atoms deposited on the threefold hollow site of Au(111) surface. Further, the distance between the electrodeposited Bi layers was 2.51 and it also agreed that Bi atoms deposited on the threefold hollow site of the Bi layer. The amount of electrodeposited Bi on Au(111) surface was 0.85 monolayer; thus, it was suggested that the electrodeposited Bi formed epitaxial layer on Au(111) surface in [BMIM]TFSA.