Study on engineering technologies in the Mizunami Underground Research Laboratory; FY2012 (Contract research)

Fukaya, Masaaki*; Noda, Masaru*; Hata, Koji*; Takeda, Yoshinori*; Akiyoshi, Kenji*; Ishizeki, Yoshikazu*; Kaneda, Tsutomu*; Sato, Shin*; Shibata, Chihoko*; Ueda, Tadashi*; et al.

JAEA-Technology 2014-019, 495 Pages, 2014/08

JAEA-Technology-2014-019.pdf:82.23MB

The researches on engineering technology in the Mizunami Underground Research Laboratory (MIU) plan consists of (1) research on engineering technology deep underground, and (2) research on engineering technology as a basis of geological disposal. The former research is mainly aimed in this study, which is categorized in (a) development of design and construction planning technologies, (b) development of construction technologies, (c) development of countermeasure technologies, and (d) development of technologies for security. In this study, the researches on engineering technology are being conducted in these four categories by using data measured during construction as a part of the second phase of the MIU plan.

Evaluation of shaft excavation technology based on construction results up to a depth of 500m at Mizunami Underground Research Laboratory

Sato, Toshinori; Mikake, Shinichiro; Noda, Masaru*; Kobayashi, Shinji*

Tonneru To Chika, 45(7), p.501 - 510, 2014/07

The Japan Atomic Energy Agency conducts studies and research associated with the excavation of underground research facility at the Mizunami Underground Research Laboratory in Mizunami City, Gifu Prefecture. The research laboratory is an underground facility consisting of two shafts and some drifts and excavation has currently extended to a depth of 500 m. This report contains the evaluation results of measures to control the welling of water and measures to prevent ground collapse based on construction records up to now. For measures to control the welling of water, we carried out pre-grouting from umbrella-shaped grouthing holes placed at the bottom of the shaft and observed improvements in given permeability. For measures to prevent ground collapse, we conducted safe shaft sinking along faults by combining reinforecement works using rock bolts and fore-poling works using silica-resin grouting. Both measures were conducted using a shaft sinking drill carriage "Shaft Jumbo" that made it possible to efficiently incorporate short step shaft sinking cycles.

Present status and future plan of development on National Nuclear Forensics Library at JAEA

Kimura, Yoshiki; Shinohara, Nobuo; Funatake, Yoshio; Sato, Kaneaki; Toda, Nobufumi; Shinoda, Yoshiharu; Watahiki, Masaru; Kuno, Yusuke

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2013/10

Japan Atomic Energy Agency (JAEA) has initiated R&D project on nuclear forensics technology such as analytical technologies towards the establishment of nuclear forensics capabilities in Japan. National Nuclear Forensics Library (NNFL) is one of the fundamental nuclear forensics capabilities and a prototype NNFL has been developed as one R&D topic of the project at JAEA. Main objective of a NNFL is to determine whether a seized nuclear or other radioactive material from nuclear security event (e.g. illicit trafficking) is originated from a country or not. Analytical data of the seized material are compared with the existing materials populated in a NNFL, and its attributions such as origin and history will be identified. This paper describes the current status and future plan on the development of prototype NNFL. The outline and the results of the participation in an international table top exercise on NNFL named "Galaxy Serpent" were also reported in the present paper.

Study on dynamic behavior of a shaft excavated through faulted crystalline rock mass

Hashizume, Shigeru; Matsui, Hiroya; Horiuchi, Yasuharu; Hata, Koji*; Akiyoshi, Kenji*; Sato, Shin*; Shibata, Chihoko*; Niunoya, Sumio*; Noda, Masaru*

Dai-13-Kai Iwa No Rikigaku Kokunai Shimpojiumu Koen Rombunshu (CD-ROM), p.121 - 126, 2013/01

The "Mizunami Underground Research Laboratory" has been studying and developing engineering technology for deep underground applications. These applications are multifaceted and are categorized as development of design and construction planning technology, development construction technology, development countermeasure technology, and development of technology for construction and operation security. In this report, the dynamic stability of shaft and surrounding rock mass has been studied with respect to rock mass displacement and stress, the effect of using a concrete liner and excavating through faulted crystalline rock.

Planning of in-situ experiment for understanding of gas migration behaviour in sedimentary rock, 2; Affects of dissolved methane to the gas migration in bedrock

Tanai, Kenji; Fujita, Tomoo; Sato, Shin*; Noda, Masaru*; Yamamoto, Shuichi*; Shimura, Tomoyuki*

Dai-13-Kai Iwa No Rikigaku Kokunai Shimpojiumu Koen Rombunshu (CD-ROM), p.173 - 178, 2013/01

Japan Atomic Energy Agency has been planning gas migration test in Horonobe URL, Hokkaido. It is expected that dissolved methane in Horonobe groundwater might have an effect on gas migration behaviour in bedrock. A series of two-phase multi-component analyses by use of GETFLOWS were conducted to understand the influence of dissolved methane. The increase of total gas pressure has been shown due to the existence of dissolved methane. The results also indicated that the injected nitrogen gas volume was influenced by dissolved methane.

Application feasibility study of an evaluation technology for long-term rock behavior; Coupled hydraulic and mechanical analyses to evaluate rock behavior of shaft in fault

Noda, Masaru*; Sato, Shin*; Niunoya, Sumio*; Hata, Koji*; Matsui, Hiroya; Mikake, Shinichiro

Dai-41-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.202 - 207, 2012/01

The main shaft of Mizunami URL is located in fault, and due to the geology hydrological anisotropy is observed. Lining deformation may cause by increase of lining stress with degradation of drain material or aquifer of changes in future. Therefore, study on evaluation method to predict the effect by water pressure change is needed. In this study, by implementing coupled hydraulic and mechanical analyses, validity of methods of analysis is considered as compared to measuring for hydrological anisotropy in the main shaft. According to the result of the study, water pressure dependency was not shown, but the main shaft behavior was simulated taking account of hydrological anisotropy. Also validity of methods of coupled hydraulic and mechanical analyses as deterioration prediction was confirmed.

Study for effectiveness of rock mechanical model estimated from pilot boring survey

Niunoya, Sumio*; Matsui, Hiroya; Mikake, Shinichiro; Sato, Shin*; Noda, Masaru*; Hata, Koji*

Dai-41-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.214 - 219, 2012/01

In the Mizunami URL of Japan Atomic Energy Agency (JAEA), the study on engineering technology are on going. In this study, we tried to estimate the static elastic modulus from RMR (Rock Mass Rating) based on the results of laboratory test, core observation of the pilot borehole and geological survey on the shaft wall of main shaft in the URL. The static elastic modulus based on PS logging in a borehole as well. Then, the three dimensional numerical analysis using of these parameters carried out for the validity of the examination. The results show that the RMR may be applicable to estimate the mechanical parameters of strongly weathered rock mass which is widely distributed in Japan.

The Project for grouting development for high level radioactive waste repository, 2; Relationship between basic properties and penetrability of low-alkaline cementitious grout material

Suzuki, Kenichiro*; Miura, Norihiko*; Iriya, Keishiro*; Noda, Masaru*; Kishi, Hirokazu

Doboku Gakkai Heisei-22-Nendo Zenkoku Taikai Dai-65-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), p.85 - 86, 2010/09

no abstracts in English

Studies on grouting performance in Mizunami Underground Research Laboratory (Contract research)

Kawamura, Hideki*; Ando, Kenichi*; Noda, Masaru*; Tanaka, Tatsuya*; Matsuda, Takeshi*; Fujii, Haruhiko*; Hashimoto, Shuji*; Ueda, Tadashi*; Matsui, Hiroya; Takeuchi, Shinji; et al.

JAEA-Technology 2009-081, 182 Pages, 2010/03

JAEA-Technology-2009-081.pdf:28.89MB

Grouting has practical importance for the reduction of groundwater inflow into excavations during construction of underground facilities. Considering the performance assessment of a radioactive waste repository, the performance of the engineered barrier system could be adversely affected by a high pH plume generated from grout. Therefore, a quantitative estimation of the effectiveness of grouting and grout material is essential. This study has been performed in the Mizunami URL being excavated in crystalline rock as a part of the Project for Grouting Technology Development for the Radioactive Waste Repository funded by METI, Japan. The aims were to evaluate the applicability of existing grouting technology and to develop methodology to determine the distribution of grout and change in hydraulic properties of the grouted rock volume. The target rock is the volume of rock around a planned refuge niche where the pre-excavation grouting was performed at 200-m depth from ground surface. After excavation of the refuge niche, ten boreholes were drilled and different kinds of investigations were carried out during and after drilling. The results were integrated and groundwater flow analysis of pre and post excavation grouting conditions were carried out to estimate quantitatively the effect of pre-excavation grouting. The results suggest that current pre-excavation grouting technology is effective for reduction of groundwater inflow into excavations and that hydraulic conductivity of the surrounding rock can be reduced by more than one order of magnitude.

Study on applicability of low alkaline cement in Horonobe Underground Research Laboratory Project, 2 (Contract research)

Nakayama, Masashi; Kobayashi, Yasushi; Matsuda, Takeshi*; Noda, Masaru*; Iriya, Keishiro*; Takeda, Nobufumi*

JAEA-Research 2009-035, 70 Pages, 2009/11

JAEA-Research-2009-035.pdf:11.27MB

In Horonobe Underground Research Center construction of underground facility began in 2005 and construction practicality test with HFSC (Highly Fly-ash contained Silica-fume Cement) is planned in a part of the gallery. Before HFSC will be placed in the gallery it is necessary to validate that HFSC has performance under the actual construction. The research results in 2007 were as follows. As corrosion behavior in HFSC, reinforced concrete specimen with HFSC 226 have been exposed to off-shore condition at in saline water and splashed zone and analyzed corrosion rate and chloride intrusion, and they were summarized. Service life time of HFSC reinforced concrete was assessed more than 50 years until cracking due to corrosion is generated. pH and components of solid and liquid phase which were made in 2002, and stored in water were analyzed. And cement paste of shotcrete which are made in 2006 were also analyzed. In this pH of shotcrete is lower than other in situ concrete since accelerating agent may act as decreasing factor of pH. The results obtained from this ten year's study were summarized on shotcerete, in situ concrete and grouting. Based on the summery, method of quality control, such as testing method, frequency, and standards so on, were investigated.