Horonobe Underground Research Laboratory Project; Investigation program for the 2023 fiscal year

Nakayama, Masashi

JAEA-Review 2023-019, 70 Pages, 2023/11

JAEA-Review-2023-019.pdf:6.83MB

The Horonobe Underground Research Laboratory (URL) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant technologies for geological disposal of high-level radioactive waste through investigating the deep geological environment within the host sedimentary rocks at Horonobe Town in Hokkaido, north Japan. In the fiscal year 2023, we continue R&D on "Study on near-field system performance in geological environment", "Demonstration of repository design options", and "Understanding of buffering behaviour of sedimentary rocks to natural perturbations". These are identified as key R&D challenges to be tackled in the Horonobe underground research plan for the fiscal year 2020 onwards. In the "Study on near-field system performance in geological environment", we conduct the coupled analysis on the full-scale engineered barrier system performance experiment and test the coupled simulation code through comparison with different simulation codes in the international DECOVALEX-2023 collaboration project. Borehole investigations are also carried out for solute transport experiments in the Koetoi Formation. As for "Demonstration of repository design concept", we carry out in situ experiments and data analysis on concrete deterioration under the subsurface conditions. Geophysical surveys are also carried out around an experimental tunnel to be newly excavated at the 350m gallery and characterise the initial conditions of the excavation damaged zone. For the "Understanding of buffering behaviour of sedimentary rocks to natural perturbations", we analyse the results of the hydraulic disturbance tests conducted in previous years and understand the relationship between rock stress / stress state and fault / fracture hydraulic connectivity. Concerning the construction and maintenance of the subsurface facilities, the 350 m gallery is extended and shafts are sank to a depth of 500 m.

Annual report for research on geosphere stability for long-term isolation of radioactive waste in fiscal year 2019

Ishimaru, Tsuneari; Ogata, Nobuhisa; Kokubu, Yoko; Shimada, Koji; Hanamuro, Takahiro; Shimada, Akiomi; Niwa, Masakazu; Asamori, Koichi; Watanabe, Takahiro; Sueoka, Shigeru; et al.

JAEA-Research 2020-011, 67 Pages, 2020/10

JAEA-Research-2020-011.pdf:3.87MB

This annual report documents the progress of research and development (R&D) in the 5th fiscal year during the JAEA 3rd Mid- and Long-term Plan (fiscal years 2015-2021) to provide the scientific base for assessing geosphere stability for long-term isolation of the high-level radioactive waste. The planned framework is structured into the following categories: (1) Development and systematization of investigation techniques, (2) Development of models for long-term estimation and effective assessment, (3) Development of dating techniques. The current status of R&D activities with previous scientific and technological progress is summarized.

Work reports on nuclear data of Sigma Special Advisory Committee in 2017-2018, 4; Working plan of Investigation Advisory Committee on Nuclear Data in the next period

Fukahori, Tokio

Kaku Deta Nyusu (Internet), (125), p.20 - 25, 2020/02

http://www.aesj.or.jp/~ndd/ndnews/pdf125/No125-04.pdf

This report is review on one of the series presentations on "Work Reports on Nuclear Data of Sigma Special Advisory Committee in 2017-2018" at the Fall Meeting of Atomic Energy Society of Japan (AESJ). In this report, the work plan of this Committee in the next two-years period is introduced. The AESJ Investigation Advisory Committee on Nuclear Data researches world-wide nuclear data activities, reports from the view point of wide range collaborative fields, contributes to Japanese nuclear data investigation activities with contacting many of related organizations.

Technical investigation on small water leakage incident occurrence in mercury target of J-PARC

Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; Naoe, Takashi; Takada, Hiroshi

Journal of Nuclear Science and Technology, 55(2), p.160 - 168, 2018/02

https://doi.org/10.1080/00223131.2017.1384706

The mercury target vessel used for the spallation neutron source in J-PARC has multi-walled structure made of stainless steel type 316L, which comprises a mercury vessel and a water shroud. In 2015, water leak incidents from the water shroud occurred while the mercury target was operated with a proton beam power of 500 kW. Several investigations were conducted to identify the cause of failure. The results of the visual inspections, mockup tests, and analytical evaluations suggested that the water leak was caused by the combination of two factors. One was the diffusion bonding failure due to the large thermal stress induced by welding of the bolt head, which fixes the mercury vessel and the water shroud, during the fabrication process. The other was the thermal fatigue failure of the seal weld due to the repetitive beam trip during the operating period. These target failures point to the importance of eliminating initial defects from welding lines and to secure the rigidity and reliability of welded structures. The next mercury target was fabricated with an improved design which adopted parts of monolithic structure machined by wire EDM to reduce welding lines, and intensified inspections to eliminate the initial defects. The operation with the improved target is planned to be started in October 2017.

Improvement in quantitative performance of underwater laser-induced breakdown spectroscopy based on the understanding of laser ablation phenomena

Matsumoto, Ayumu

Reza Kako Gakkai-Shi, 23(3), p.222 - 231, 2016/10

no abstracts in English

Effective 3D data visualization in deep shaft construction

Inagaki, Daisuke*; Tsusaka, Kimikazu*; Aoyagi, Kazuhei; Nago, Makito*; Ijiri, Yuji*; Shigehiro, Michiko*

Proceedings of ITA-AITES World Tunnel Congress 2015 (WTC 2015)/41st General Assembly, 10 Pages, 2015/05

Development of flow visualization technique for measurement of exchange flow rates under LOVA condition and results of the preliminary flow visualization experiment

Kunugi, Tomoaki; Takase, Kazuyuki; Ogawa, Masuro; Shibata, Mitsuhiko

JAERI-Tech 96-012, 91 Pages, 1996/03

JAERI-Tech-96-012.pdf:3.51MB

no abstracts in English

Investigation of the Be(He,n)C reaction in the energy range 3.5-10 MeV

*; ; ;

Nuclear Physics A, 115(1), p.17 - 32, 1968/00

https://doi.org/10.1016/0375-9474(68)90639-8

no abstracts in English

Work reports on nuclear data of Sigma Special Advisory Committee in 2017-2018, 4; Working plan of Investigation Advisory Committee on Nuclear Data in the next period

Fukahori, Tokio

no journal, , 

This report is one of the series presentations on "Work Reports on Nuclear Data of Sigma Special Advisory Committee in 2017-2018". The Investigation Advisory Committee on Nuclear Data researches world-wide nuclear data activities, reports from the view point of wide range collaborative fields, contributes to Japanese nuclear data investigation activities with contacting many of related organizations. In this presentation, the work plan of the Committee in the next two-years period is introduced.