Fully chelating NO-pentadentate planar ligands designed for the strongest and selective capture of uranium from seawater

Mizumachi, Takumi*; Sato, Minami*; Kaneko, Masashi; Takeyama, Tomoyuki*; Tsushima, Satoru*; Takao, Koichiro*

Inorganic Chemistry, 61(16), p.6175 - 6181, 2022/04

https://doi.org/10.1021/acs.inorgchem.2c00306

Based on unique 5-fold equatorial coordination of UO, water-compatible pentadentate planar ligands, Hsaldian and its derivatives, were designed as strong and selective capture of UO in seawater. In the simulated seawater condition (0.5 M NaCl + 2.3 mM HCO/CO, pH 8), saldian shows the strongest complexation with UO to form UO(saldian) (log = 28.05 0.07), which is more than 10 order of magnitude greater than amidoxime-based or -inspired ligand systems most commonly employed for U capture from seawater. Good selectivity for UO from other metal ions coexisting in seawater was also demonstrated.

The First electron bunch measurement by means of dast organic EO crystals

Okayasu, Yuichi*; Tomizawa, Hiromitsu*; Matsubara, Shinichi*; Sato, Takahiro*; Ogawa, Kanade*; Togashi, Tadashi*; Takahashi, Eiji*; Minamide, Hiroaki*; Matsukawa, Ken*; Aoyama, Makoto; et al.

Proceedings of 1st International Beam Instrumentation Conference (IBIC 2012) (Internet), 5 Pages, 2012/10

http://accelconf.web.cern.ch/Accelconf/IBIC2012/talks/mocc03_talk.pdf

no abstracts in English

Studies on planning and conducting for reducing water inflow due to underground construction in crystalline rock

Mikake, Shinichiro; Yamamoto, Masaru; Ikeda, Koki; Sugihara, Kozo; Takeuchi, Shinji; Hayano, Akira; Sato, Toshinori; Takeda, Shinichi; Ishii, Yoji; Ishida, Hideaki; et al.

JAEA-Technology 2010-026, 146 Pages, 2010/08

JAEA-Technology-2010-026.pdf:41.08MB
JAEA-Technology-2010-026-appendix(CD-ROM).zip:83.37MB

The Mizunami Underground Research Laboratory (MIU), one of the main facilities in Japan for research and development of the technology for high-level radioactive waste disposal, is under construction in Mizunami City. In planning the construction, it was necessary to get reliable information on the bedrock conditions, specifically the rock mass stability and hydrogeology. Therefore, borehole investigations were conducted before excavations started. The results indicated that large water inflow could be expected during the excavation around the Ventilation Shaft at GL-200m and GL-300m Access/Research Gallery. In order to reduce water inflow, pre-excavation grouting was conducted before excavation of shafts and research tunnels. Grouting is the injection of material such as cement into a rock mass to stabilize and seal the rock. This report describes the knowledge and lessons learned during the planning and conducting of pre-excavation grouting.

Countermeasures planned for reducing water inflow into deep shafts at the Mizunami Underground Research Laboratory

Kuji, Masayoshi; Sato, Toshinori; Mikake, Shinichiro; Hara, Masato; Minamide, Masashi; Sugihara, Kozo

Journal of Power and Energy Systems (Internet), 2(1), p.153 - 163, 2008/00

https://doi.org/10.1299/jpes.2.153

The Mizunami Underground Research Laboratory (MIU) is being constructed. The MIU consists of two 1,000 m-deep shafts with several research galleries. The goals of MIU project are to establish techniques for investigation, analysis and assessment of deep geological environment, and to develop a range of engineering expertise for application to deep underground crystalline rocks, such as Granite. The diameter of the Main and the Ventilation shafts are 6.5 m and 4.5 m respectively. The Middle stage at about 500 m depth, and the Main stage at about 1,000 m depth will be the main locations for scientific investigations. Current depths of both shafts are 200 m, in August 2007.During the construction, the water inflow into the shafts is increasing and disturbing the project progress. For reducing the water inflow, post-excavation grouting was planned. A test of post-excavation grouting was undertaken and the applicability of several techniques was evaluated.

Post-grouting test to reduce water inflow into deep shaft

Kuji, Masayoshi; Sato, Toshinori; Hara, Masato; Mikake, Shinichiro; Minamide, Masashi

Tonneru Kogaku Hokokushu (CD-ROM), 16, p.469 - 476, 2006/11

http://library.jsce.or.jp/jsce/open/00047/2006/16-0469.pdf

In the Mizunami Underground Research Laboratory (MIU), two 1,000m-deep shafts and several research galleries are being constructed. Water inflow into the shafts during shaft sinking is disturbing the project progress. As a countermeasure for this problem, post-grouting is being considered and post-grouting test has been undertaken in one of the shafts. This report gives an outline of the work plan and results of the post-grouting test.

Pre-grouting to reduce water inflow into the Mizunami Underground Research Laboratory

Hara, Masato; Kuji, Masayoshi; Minamide, Masashi; Mikake, Shinichiro; Sato, Toshinori; Ikeda, Koki

no journal, , 

In the Mizunami Underground Research Laboratory, water inflow into the shafts is disturbing the project progress. As a countermeasure for this problem, pre-grouting is being considered and pre-grouting has been undertaken in the shafts. This report describes an outline of the work results of pre-grouting.

In-situ experiment of shotcrete using low alkaline cement in Horonobe Underground Research Laboratory, 2; Low alkaline cement used in the construction of a gallery

Kitagawa, Yoshito*; Minamide, Masashi*; Nayuki, Toshinori*; Yamanishi, Takeshi; Sekiya, Yoshitomo; Ito, Seiji; Sato, Haruo; Nakayama, Masashi

no journal, , 

In Japan, any high level radioactive waste repository is to be constructed at over 300m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various additives. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (High fly-ash silicafume cement), containing over 60wt% of silica-fume (SF) and coal ash (FA). JAEA are presently constructing an underground research laboratory (URL) at Horonobe for research and development in the geosciences and repository engineering technology. HFSC was used experimentally as the shotcrete material in construction of part of the 140m deep gallery in Horonobe URL. The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40wt% OPC (Ordinary Portland Cement), 20wt% SF, and 40wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC in normal concrete. The total length of tunnel using HFSC shotcrete is about 73m and about 500m of HFSC was used. This experimental construction confirmed the workability of HFSC shotcrete. Although several in-situ experiments using low alkaline cement as shotcrete have been performed at a small scale, this application of HFSC at the Horonobe URL is the first full scale application of low alkaline cement in the construction of a URL in the world.