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Nakayama, Masashi; Ishii, Eiichi; Aoyagi, Kazuhei; Hayano, Akira; Murakami, Hiroaki; Ono, Hirokazu; Takeda, Masaki; Fukatsu, Yuta; Mochizuki, Akihito; Ozaki, Yusuke; et al.
JAEA-Review 2025-042, 136 Pages, 2025/12
JAEA-Review-2025-042.pdf:12.95MB
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-cho in Hokkaido, north Japan. In the fiscal year 2024, we continued R&D on "Study on near-field system performance in geological environment", "Demonstration of repository design options", and "Understanding of buffering behaviour of sedimentary rock to natural perturbations". These are identified as key R&D on challenges to be tackled in the Horonobe underground research plan for the fiscal year 2020 onwards. Specifically, "full-scale engineered barrier system (EBS) performance experiment" and "solute transport experiment with model testing" were carried out as part of "Study on near-field system performance in geological environment". "Demonstration of engineering feasibility of repository technology" and "evaluation of EBS behaviour over 100
C" were addressed for "Demonstration of repository design options". The validation of a method for assessing permeability using the Ductility Index and a method for estimating the state of in-situ ground pressure from hydraulic perturbation tests were investigated as part of the study "Understanding of buffering behaviour of sedimentary rock to natural perturbations". In FY2024, we continued construction of the East Access Shaft and the Ventilation Shaft, and construction of these shafts were completed to a depth of 500 m. After the completion of the East Access Shaft, excavation of the West Access Shaft and 500 m gallery has began. As of the end of FY2024, excavation progress is as follows, the East Access Shaft and the Ventilation Shaft were 500 m depth, the West Access Shaft was 472 m depth, 500 m gallery was 112.9 m, respectively. In the Horonobe International Project (HIP), Management Board and Joint Task Meeting was held at the Horonobe URL in June 2024 to review the progress of construction of galleries and preparations of experiments. Task Meetings to review the implementation plan for in-situ testing and analysis were also held. HIP will be implemented in two phases: Phase 1 (from FY2022 to FY2024) and Phase 2 (from FY2025 to FY2028), the research results of Phase 1 were compiled in FY2024.
Tachi, Yukio; Aoyagi, Kazuhei; Ozaki, Yusuke; Hayano, Akira; Ono, Hirokazu; Takeda, Masaki; Mochizuki, Akihito; Dei, Shuntaro; Minaka, Jumpei; Murakami, Hiroaki; et al.
NEA/NE(2025)20 (Internet), 118 Pages, 2025/11
Hayano, Akira; Aoyagi, Kazuhei; Murakami, Hiroaki; Kimura, Shun
Proceedings of 2025 International High Level Radioactive Waste Management Conference (IHLRWM 2025) (Internet), p.8 - 11, 2025/11
Nakayama, Masashi; Ishii, Eiichi; Hayano, Akira; Aoyagi, Kazuhei; Murakami, Hiroaki; Ono, Hirokazu; Takeda, Masaki; Mochizuki, Akihito; Ozaki, Yusuke; Kimura, Shun; et al.
JAEA-Review 2025-027, 80 Pages, 2025/09
JAEA-Review-2025-027.pdf:6.22MB
The Horonobe Underground Research Laboratory Project is being pursued by the Japan Atomic Energy Agency 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 2025, we continue R&D on "Study on near-field system performance in geological environment" and "Demonstration of repository design options". 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 continue to obtain data from the full-scale engineered barrier system performance experiment, and work on the specifics of the full-scale engineered barrier system dismantling experiment. As for "Demonstration of repository design options", the investigation, design, and evaluation techniques are to be systemized at various scales, from the tunnel to the pit, by means of an organized set of evaluation methodologies for confinement performance at these respective scales. Preliminary borehole investigations will be conducted within a 500 m gallery, with the objectives of obtaining rock strength and rock permeability data, as well as surveying the extent of the excavation damaged zone surrounding the test tunnel via tomographic analysis. A planning study for the in-situ construction test will be conducted to investigate the construction of backfill material and watertight plugs. The volume of water inflow associated with the excavation of the 500 m gallery will be observed, and its magnitude will be compared with the range of water inflow predicted in the analysis. The test plan to determine the extent of the excavation damaged zone around the pit, which is planned to be constructed in the 500 m gallery, will be studied to determine the in-situ excavation damaged zone. In addition, the investigation and evaluation methods for the amount of water inflow from fractures and the extent of the excavation damaged zone around the pit will be organized. Concerning the construction and maintenance of the subsurface facilities, excavation of the West Access Shaft and the 500 m gallery will continue. It is anticipated that the construction of the facilities will be completed by the end of the fiscal year 2025. In addition, we continue R&D on the following three tasks in the Horonobe International Project; Task A: Solute transport experiment with model testing, Task B: Systematic integration of repository technology options, and Task C: Full-scale engineered barrier system dismantling experiment.
Aoyagi, Kazuhei; Tamura, Tomonori; Murakami, Hiroaki; Hayano, Akira; Ozaki, Yusuke; Ono, Hirokazu; Ishii, Eiichi
Shigen, Sozai Koenshu (Internet), 12(2), 7 Pages, 2025/09
no abstracts in English
Kataoka, Takahiro*; Shuto, Hina*; Naoe, Shota*; Yano, Junki*; Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Hanamoto, Katsumi*; Mitsunobu, Fumihiro*; Terato, Hiroaki*; et al.
Journal of Radiation Research (Internet), 62(5), p.861 - 867, 2021/09
Times Cited Count：6 Percentile：38.59(Biology)Kataoka, Takahiro*; Kanzaki, Norie; Sakoda, Akihiro; Shuto, Hina*; Yano, Junki*; Naoe, Shota*; Tanaka, Hiroshi; Hanamoto, Katsumi*; Terato, Hiroaki*; Mitsunobu, Fumihiro*; et al.
Journal of Radiation Research (Internet), 62(2), p.206 - 216, 2021/03
Times Cited Count：7 Percentile：43.75(Biology)Radon inhalation activates antioxidative functions in mouse organs, thereby contributing to inhibition of oxidative stress-induced damage. Therefore, in this study, we evaluated the redox state of various organs in mice following radon inhalation. Mice inhaled radon at concentrations of 2 or 20 kBq/m
for 1, 3, or 10 days. The relationship between antioxidative function and oxidative stress was evaluated by principal component analysis (PCA) and correlation coefficient compared with control mice subjected to sham inhalation. These findings suggested that radon inhalation altered the redox state in organs, but that the characteristics varied depending on the redox state in organs.
Yasuda, Satoshi; Uchibori, Yosuke*; Wakeshima, Makoto*; Hinatsu, Yukio*; Ogawa, Hiroaki; Yano, Masahiro; Asaoka, Hidehito
RSC Advances (Internet), 8(66), p.37600 - 37605, 2018/11
Times Cited Count：13 Percentile：37.39(Chemistry, Multidisciplinary)We present a quantitative study on the effect of a newly obtained thermal history on the formation of Fe-N-C catalytic sites. A short and repeated heating process is employed as the new thermal history, where short heating (1 min) followed by quenching is applied to a sample with arbitrary repetition. Through electrochemical quantitative analysis, it is found that the new process effectively increases the Fe-N-C mass-based site density (MSD) to almost twice that achieved using a conventional continuous heating process, while the turn-over frequency (TOF) is independent of the process. Elemental analysis shows that the new process effectively suppresses the thermal desorption of Fe and N atoms during the initial formation stage and consequently contributes to an increase in the Fe-N-C site density. The resultant catalytic activity (gravimetric kinetic current density (0.8 V vs. RHE)) is 1.8 times higher than that achieved with the continuous heating process.
Sato, Toshinori; Sasamoto, Hiroshi; Ishii, Eiichi; Matsuoka, Toshiyuki; Hayano, Akira; Miyakawa, Kazuya; Fujita, Tomoo*; Tanai, Kenji; Nakayama, Masashi; Takeda, Masaki; et al.
JAEA-Research 2016-025, 313 Pages, 2017/03
JAEA-Research-2016-025.pdf:45.1MB
The Horonobe Underground Research Laboratory (URL) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formations at Horonobe, northern Hokkaido. This report summarizes the results of the Phase II investigations carried out from April 2005 to June 2014 to a depth of 350m. Integration of work from different disciplines into a "geosynthesis" ensures that the Phase II goals have been successfully achieved and identifies key issues that need to made to be addressed in the Phase II investigations Efforts are made to summarize as many lessons learnt from the Phase II investigations and other technical achievements as possible to form a "knowledge base" that will reinforce the technical basis for both implementation and the formulation of safety regulations.
Co
-ray irradiation effects on pentacene-based organic thin film transistorsCai, L.*; Hirao, Toshio; Yano, Hiroaki*; Duan, Z.*; Takayanagi, Yutaro*; Ueki, Hideharu*; Oshima, Takeshi; Nishioka, Yasushiro*
Materials Science Forum, 687, p.576 - 579, 2011/06
Times Cited Count：6 Percentile：91.39(Engineering, Electrical & Electronic)no abstracts in English
Kunimaru, Takanori; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Hayano, Akira; Takeuchi, Ryuji; Saegusa, Hiromitsu; Oyama, Takuya; Mizuno, Takashi; et al.
JAEA-Review 2011-007, 145 Pages, 2011/03
JAEA-Review-2011-007.pdf:16.51MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). Geoscientific research and the MIU Project are planned in three overlapping phases; 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 introduces the results of the research and development in fiscal year 2009, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site and the Shobasama Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration, etc. The goals of the Phase 2 are to develop and revise the models of the geological environment using the investigation results obtained during excavation and determine and assess changes in the geological environment in response to excavation, to evaluate the effectiveness of engineering techniques used for construction, maintenance and management of underground facilities, to establish detailed investigation plans of Phase 3.
Co -ray irradiated pentacene-based organic thin film field effect transistorsCai, L.*; Hirao, Toshio; Yano, Hiroaki*; Duan, Z.*; Takayanagi, Hideharu*; Ueki, Hideharu*; Oshima, Takeshi; Nishioka, Yasushiro*
Proceedings of 9th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-9), p.176 - 178, 2010/10
no abstracts in English
Takeuchi, Shinji; Kunimaru, Takanori; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Hayano, Akira; Takeuchi, Ryuji; Saegusa, Hiromitsu; Oyama, Takuya; et al.
JAEA-Review 2010-029, 28 Pages, 2010/08
JAEA-Review-2010-029.pdf:3.43MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). Geoscientific research and the MIU project is planned in three overlapping phases; Surface-based investigation phase (Phase1), Construction phase (Phase2) and Operation phase (Phase3). The project is currently under the construction phase, and the operation phase starts in 2010. This document introduces the research and development activities planned for 2010 fiscal year plan based on the MIU master plan updated in 2010, (1) Investigation plan, (2) Construction plan, (3) Research collaboration plan, etc.
Takeuchi, Shinji; Kunimaru, Takanori; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Hayano, Akira; Takeuchi, Ryuji; Saegusa, Hiromitsu; Oyama, Takuya; et al.
JAEA-Review 2010-014, 110 Pages, 2010/07
JAEA-Review-2010-014.pdf:27.34MB
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 I), Construction Phase (Phase II) and Operation Phase (Phase III). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in fiscal year 2008, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site and the Shobasama Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Takeuchi, Shinji; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Amano, Kenji; Matsuoka, Toshiyuki; Hayano, Akira; Takeuchi, Ryuji; Saegusa, Hiromitsu; Oyama, Takuya; et al.
JAEA-Review 2009-017, 29 Pages, 2009/08
JAEA-Review-2009-017.pdf:3.69MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named the 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 the MIU project 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 2009 fiscal year plan based on the MIU Master Plan updated in 2002, (1) Investigation Plan, (2) Construction Plan, (3) Research Collaboration Plan, etc.
Michizono, Shinichiro*; Anami, Shozo*; Katagiri, Hiroaki*; Fang, Z.*; Matsumoto, Toshihiro*; Miura, Takako*; Yano, Yoshiharu*; Yamaguchi, Seiya*; Kobayashi, Tetsuya
Kasokuki, 5(2), p.127 - 136, 2008/07
One of the biggest advantages of the digital low level rf (LLRF) system is its flexibility. Owing to the recent rapid progress in digital devices (such as ADCs and DACs) and telecommunication devices (mixers and IQ modulators), digital LLRF system for accelerators becomes popular in these 10 years. The J-PARC linac LLRF system adopted cPCI crates and FPGA based digital feedback system. After the successful operation of J-PARC linac LLRF system, we developed the STF (ILC test facility in KEK) LLRF system. The future R&D projects (ILC and ERL) are also described from the viewpoints of LLRF.
Kuwabara, K.*; Kurishita, Hiroaki*; Ukai, Shigeharu; Narui, Makoto*; Mizuta, Shunji; Yamazaki, M.*; Kayano, H.*
Journal of Nuclear Materials, 258-263(Part 2), p.1236 - 1241, 1998/10
Times Cited Count：29 Percentile：87.84(Materials Science, Multidisciplinary)None
Sayano, Akio*; Kano, Fumihisa*; Saito, Norihisa*; Abe, Hiroaki*; Okamoto, Koji*; Takamasa, Tomoji*; Furuya, Masahiro*; Miyano, Masami*; Yoshikawa, Masahito
no journal, ,
no abstracts in English
solid solutions added stabilizing compounds for ZrOIkeuchi, Hirotomo; Yano, Kimihiko; Ogino, Hideki; Saiki, Yohei*; Honda, Masaki*; Kinoshita, Hideaki*; Muta, Hiroaki*; Yamanaka, Shinsuke*
no journal, ,
In the case of Fukushima Daiichi Nuclear Power Station (1F) Accident, it is estimated that the fuel assemblies were damaged seriously and that fuel deburis deposits in the core or the bottom of vessel. The methodology of defueling such as cutting and core boring is considered referring the case of Three Mile Island Unit 2 (TMI-2) Accident. It is supposed that fuel debris have various characteristics depending on the location. Especially, the information on mechanical properties of fuel debris is important in order to select and develop the defueling technologies. In this work, (U,Zr)O as simulated debris including YO
, CeO, CaO, which exist as a fisson product or a component of concrete and behavior as stabilizer for ZrO, was prepared and their mechanical properties were evaluated.
