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Hoshino, Masato; Sasaki, Yoshifumi; Horikoshi, Hidehiko*; Tani, Kosuke*
JAEA-Review 2025-047, 122 Pages, 2026/03
JAEA-Review-2025-047.pdf:3.75MB
Horonobe Underground Research Center managed by Japan Atomic Energy Agency (JAEA) is the Japan's best environment to understand the project of geological disposal of high-level radioactive waste, because there is an Underground Research Laboratory (URL) in the center besides an exhibition facility which explains the content of research conducted in the URL. In the area of the center, there is also an exhibition facility for the full-scale model of engineered barrier system of geological disposal. JAEA takes advantage of this opportunity to conduct public hearing including questionnaire research regarding the questions, anxieties and comments by the visitors for geological disposal project. This report summarizes the result of statistical analysis of 2,830 visitors from April 2024 to January 2025.
Hoshino, Masato; Inoue, Yuichi; Horikoshi, Hidehiko*; Tani, Kosuke*
JAEA-Review 2024-063, 120 Pages, 2026/02
JAEA-Review-2024-063.pdf:3.4MB
Horonobe Underground Research Center managed by Japan Atomic Energy Agency (JAEA) is the Japan's best environment to understand the project of geological disposal of high-level radioactive waste, because there is an Underground Research Laboratory (URL) in the center besides an exhibition facility which explains the content of research conducted in the URL. In the area of the center, there is also an exhibition facility for the full-scale model of engineered barrier system of geological disposal. JAEA takes advantage of this opportunity to conduct public hearing including questionnaire research regarding the questions, anxieties and comments by the visitors for geological disposal project. This report summarizes the result of statistical analysis of 2,696 visitors from April 2023 to January 2024.
Komatsu, Seiji; Nishida, Tetsuro; Kawasaki, Ichio; Gunji, Hikaru; Nishino, Shohei; Kambara, Takashi*; Miura, Hirohito*; Suzuki, Takaichi*; Kinoshita, Masato*; Kanei, Tatsuya*
Nihon Hozen Gakkai Dai-21-Kai Gakujutsu Koenkai Yoshishu, 5 Pages, 2025/07
Steam used for process and air conditioning in each facility at the Nuclear Fuel Cycle Engineering Institute is generated by a water tube boiler installed in the Institute's central control room and supplied to each facility via underground trenches. There are three steam supply pipelines (A, B, and C) to each facility, with two of these (A and B) designated for the reprocessing facility. The steam pipelines, including expansion joints and steam traps, are covered with insulation. The two steam pipelines for the reprocessing facility (A and B) are laid parallel, creating a structure that makes inspection and maintenance difficult. In particular, the expansion joints are spaced very closely between the A and B lines, making insulation removal difficult, which has been a challenge in performing visual inspections of the expansion joint bodies. This paper reports on the features and effects of an improved insulation system designed to allow for easy removal and installation.
Nishino, Shohei; Nishida, Tetsuro; Kawasaki, Ichio; Motohashi, Masahiro; Kambara, Takashi*; Suzuki, Takaichi*; Kinoshita, Masato*
Nihon Hozen Gakkai Dai-20-Kai Gakujutsu Koenkai Yoshishu, p.14 - 21, 2024/08
Steam is used to a process and air conditioning in Nuclear fuel Cycle engineering Laboratories (NCL). The steam is used mainly in Reprocessing Plant, and it is supplied by two steam plumbing. A leak occurred from the steam plumbing in November, 2022. As a result of cause investigation, I estimated that it had leaked by a water hammer caused for the trouble of the steam trap.
Tanimura, Yoshihiko; Yoshitomi, Hiroshi; Nishino, Sho; Tsuji, Tomoya; Fukami, Tomoyo; Shinozuka, Tomoki; Oishi, Kohei; Ishii, Masato; Takamiya, Kei; Onuki, Takaya; et al.
Radiation Measurements, 176, p.107196_1 - 107196_6, 2024/08
Times Cited Count：1 Percentile：27.40(Nuclear Science & Technology)The ICRU has proposed to change the definitions of the operational quantities used for the area and individual monitoring for external exposure in the ICRU Report 95. As introducing the new operational quantities into the radiation monitoring may affect the dose assessment results using the present personal dosimeters, it is necessary to characterize the energy spectrum in the workplace and the energy dependency of the dosimeters to be used. In this work the photon spectra were measured using a NaI(Tl) scintillation detector or a LaBr
(Ce) scintillation detector at the workplaces in the Japanese Research Reactor No.3 (JRR-3) and the Japan Proton Accelerator Research Complex (J-PARC) at Japan Atomic Energy Agency (JAEA). Then the present and new operational quantities were evaluated using the above mention spectra at the workplaces and compared each other.
Taguchi, Shigeo; Taguchi, Katsuya; Makino, Risa; Yamanaka, Atsushi; Suzuki, Kazuyuki; Takano, Masato; Koshino, Katsuhiko; Ishida, Michihiko; Nakano, Takafumi; Yamaguchi, Toshiya
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.499 - 502, 2021/07
In 2018, Tokai Reprocessing Plan (TRP) shifted to the decommissioning stage. In order to proceed with steady decommissioning work, TRP effort to enhance project management function. This paper describes the establishment and role of the Decommissioning Project Management Office, effectiveness of applying the project management tool and its utilization concept, and the method of materialize the equipment dismantling plan.
Nishino, Saki; Tsuboi, Masatoshi; Okada, Jumpei; Saegusa, Yu; Omori, Kazuki; Yasuo, Kiyoshi; Seshimo, Kazuyoshi; Domura, Kazuyuki; Yamamoto, Masahiko
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.541 - 548, 2021/07
no abstracts in English
Nogami, Toshinobu; Hoshino, Masato; Tokunaga, Hiroaki*; Horikoshi, Hidehiko*
JAEA-Review 2020-005, 120 Pages, 2020/07
JAEA-Review-2020-005.pdf:4.31MB
Horonobe Underground Research Center managed by Japan Atomic Energy Agency (JAEA) is the Japan's best environment to understand the project of geological disposal of high-level radioactive waste, because there is an Underground Research Laboratory (URL) in the center besides an exhibition facility which explains the content of research conducted in the URL. In the area of the center, there is also an exhibition facility for the full-scale model of engineered barrier system of geological disposal. JAEA takes advantage of this opportunity to conduct public hearing including questionnaire research regarding the questions, anxieties and comments by the visitors for geological disposal project. This report summarizes the result of statistical analysis of 3,349 visitors from April 2018 to January 2019.
Nogami, Toshinobu; Hoshino, Masato; Tokunaga, Hiroaki*; Horikoshi, Hidehiko*
JAEA-Review 2019-004, 116 Pages, 2019/08
JAEA-Review-2019-004.pdf:6.89MB
Horonobe Underground Research Center managed by Japan Atomic Energy Agency (JAEA) is the Japan's best environment to understand the project of geological disposal of high-level radioactive waste, because there is an Underground Research Laboratory (URL) in the center besides an exhibition facility which explains the content of research conducted in the URL. In the area of the center, there is also an exhibition facility for the full-scale model of engineered barrier system of geological disposal. JAEA takes advantage of this opportunity to conduct public hearing including questionnaire research regarding the questions, anxieties and comments by the visitors for geological disposal project. This report summarizes the result of statistical analysis of 3,842 visitors from April 2017 to January 2018.
Osawa, Hideaki; Nogami, Toshinobu; Hoshino, Masato; Tokunaga, Hiroaki*; Horikoshi, Hidehiko*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 26(1), p.45 - 55, 2019/06
Japan Atomic Energy Agency has performed risk communication at Horonobe Underground Research Center, using the Public Information House and Underground Research Laboratory (URL), to promote understanding R&D of geological disposal technology and waste disposal against public. In this paper, we conducted the analysis of questionnaire investigation performing after visiting those facilities from FY2013 to FY2017. The results show that long-term safety would gain prominent attention as agita factor by growing understanding. The results also shows that visiting to those facility would become valuable experience to understand geological disposal because, for example, respondents with visiting to URL positively evaluated necessity, appropriates and safety of geological disposal, compared with those without visiting URL.
Nogami, Toshinobu; Hoshino, Masato; Tokunaga, Hiroaki*; Horikoshi, Hidehiko*; Kawabata, Kazuki*
JAEA-Review 2018-003, 151 Pages, 2018/03
JAEA-Review-2018-003.pdf:3.94MB
Horonobe Underground Research Center managed by Japan Atomic Energy Agency (JAEA) is the Japan's best environment to understand the project of geological disposal of high-level radioactive waste, because there is an Underground Research Laboratory (URL) in the center besides an exhibition facility which explains the content of research conducted in the URL. In the area of the center, there is also an exhibition facility for the full-scale model of engineered barrier system of geological disposal. JAEA takes advantage of this opportunity to conduct public hearing including questionnaire research regarding the questions, anxieties and comments by the visitors for geological disposal project. This report summarizes the result of statistical analysis of 2,795 visitors from April to November in 2016.
Fujiwara, Toshiyuki; Hoshino, Masato; Tokunaga, Hiroaki*; Horikoshi, Hidehiko*
JAEA-Review 2017-008, 128 Pages, 2017/07
JAEA-Review-2017-008.pdf:8.28MB
Horonobe Underground Research Center managed by Japan Atomic Energy Agency (JAEA) is the Japan's best environment to understand the project of geological disposal of high-level radioactive waste, because there is an Underground Research Laboratory (URL) in the center besides an exhibition facility which explains the content of research conducted in the URL. In the area of the center, there is also an exhibition facility for the full-scale model of engineered barrier system of geological disposal. JAEA takes advantage of this opportunity to conduct public hearing including questionnaire research regarding the questions, anxieties and comments by the visitors for geological disposal project. This report summarizes the result of statistical analysis of 2,674 visitors from April to November in 2015.
Kawasaki, Masatsugu; Nakajima, Junya; Yoshida, Keisuke; Kato, Saori; Nishino, Sho; Nozaki, Teo; Nakagawa, Masahiro; Tsunoda, Junichi; Sugaya, Yuki; Hasegawa, Rie; et al.
JAEA-Data/Code 2017-004, 57 Pages, 2017/03
JAEA-Data-Code-2017-004.pdf:2.34MB
In emergency situation of nuclear facilities, we need to estimate the radiation dose due to radiation and radioactivity to grasp the influence range of the accident in the early stage. Therefore, we prepare the case studies of dose assessment for public exposure dose and personal exposure dose and contribute them to emergency procedures. This document covers about accidents of nuclear facilities in Nuclear Science Research Institute and past accident of nuclear power plant, and it can be used for inheritance of techniques of emergency dose assessment.
Fujiwara, Toshiyuki; Katada, Inao; Hoshino, Masato; Tokunaga, Hiroaki*; Horikoshi, Hidehiko*
JAEA-Review 2015-035, 103 Pages, 2016/03
JAEA-Review-2015-035.pdf:5.65MB
Horonobe Underground Research Center managed by Japan Atomic Energy Agency (JAEA) is the Japan's best environment to understand the project of geological disposal of high-level radioactive waste of Japan because there is an underground research laboratory (URL) in the center besides an exhibition facility which explains the content of research conducted in the URL. In the area of the center, there is also an exhibition facility for the full-scale model of engineered barrier system of geological disposal. JAEA takes advantage of this opportunity to conduct public hearing including questionnaire research regarding the questions, anxieties and comments by the visitors for geological disposal project. This report summarizes the result of statistical analysis of 2457 comments by the visitors from April to November in 2014.
Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Nishikino, Masaharu; Ishino, Masahiko; Ichimaru, Satoshi*; Hatayama, Masatoshi*; Hasegawa, Noboru; Kawachi, Tetsuya
Reza Gakkai Dai-483-Kai Kenkyukai Hokoku; Tanhacho Ryoshi Bimu Hassei To Sono Oyo, p.25 - 28, 2015/12
X-ray ablation has been recently achieved using plasma soft X-ray lasers (SXRLs), laser plasma soft X-rays, and X-ray free electron lasers. In order to study the interactions between picosecond SXRL beams and material and multi-layered structure surfaces were irradiated with SXRL pulse. Following irradiation, the substrate surface was observed using a scanning electron microscope and an atomic force microscope. The surface modifications caused by the SXRL beam were clearly seen. The multi-layered mirror is the important component for the EUV lithography. Then, we have started the damage test of multi-layered structure, and the surface modifications caused by the SXRL pulse irradiations were confirmed.
Fujita, Tomoo; Tanai, Kenji; Nakayama, Masashi; Sawada, Sumiyuki*; Asano, Hidekazu*; Saito, Masahiko*; Yoshino, Osamu*; Kobayashi, Masato*
JAEA-Research 2014-031, 44 Pages, 2015/03
JAEA-Research-2014-031.pdf:16.11MB
Japan Atomic Energy Agency (JAEA) and Radioactive Waste Management Funding and Research Center (RWMC) concluded the letter of cooperation agreement on the research and development of radioactive waste disposal in April, 2005, and have been carrying out the collaboration work based on the agreement. JAEA have been carrying out the Horonobe Underground Research Laboratory (URL) Project which is intended for a sedimentary rock in the Horonobe town, Hokkaido, since 2001. In the project, geoscientific research and research and development on geological disposal technology are being promoted. Meanwhile, the government (the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry) has been promoting construction of equipments for the full-scale demonstration of engineered barrier system (EBS) and operation technology for high-level radioactive waste (HLW) disposal since 2008, to enhance public's understanding to the geological disposal of HLW, e.g. using underground facility. RWMC received an order of the project in fiscal year 2012 (2011/2012) continuing since fiscal year 2008 (2008/2009). Since topics in this project are included in the Horonobe URL Project, JAEA carried out this project as collaboration work continuing since fiscal year 2008. This report summarizes the results of engineering technology carried out in this collaboration work in fiscal year 2013. In fiscal year 2013, emplacement tests using buffer material block for the vertical emplacement concept were carried out and visualization tests for water penetration in buffer material were carried out.
Koike, Masato; Imazono, Takashi; Ishino, Masahiko
Advances in X-Ray Chemical Analysis, Japan, 46, p.159 - 166, 2015/03
The demand for the physical-properties research using powerful light sources, such as synchrotron radiation and soft-X-rays laser light, is increasing. When promoting such research, it is required to develop efficient soft-X-ray spectrometers suitable for absorption, emission, and fluorescence which are appeared in an energy rage of 1-8 keV. We describe the development of laminar type diffraction gratings which enhance diffraction efficiency remarkably by use of soft-X-ray multilayers instead of single metal layers.
Abe, Shinya; Katada, Inao; Hoshino, Masato; Tokunaga, Hiroaki*; Horikoshi, Hidehiko*
JAEA-Review 2014-034, 81 Pages, 2014/11
JAEA-Review-2014-034.pdf:8.76MB
The Horonobe Underground Research Center conducts research and development to enhance the reliability of geological disposal technology, indicate the margin of technical safety for legally decided depth of repository, improve understanding of the deep geological environment, and promote greater public understanding for geological disposal technology. "YUME chisoukan" ceased its role as an exhibition facility as of end August 2012 as part of an administrative reform under the then Democratic Party rule, and came to be focused on disclosing the underground drifts to ascertain that JAEA is true to its tripartite agreement signed between the Hokkaido Prefecture, Town of Horonobe and JAEA (i.e., no nuclear materials will be used, etc.). It is also used as the facility to provide information on the research results of the Center. This report presents the statistical results of a questionnaire (2,566 responses) conducted from April to October 2013.
Someya, Yoji; Tobita, Kenji; Yanagihara, Satoshi*; Kondo, Masatoshi*; Uto, Hiroyasu; Asakura, Nobuyuki; Hoshino, Kazuo; Nakamura, Makoto; Sakamoto, Yoshiteru
Fusion Engineering and Design, 89(9-10), p.2033 - 2037, 2014/10
Times Cited Count：11 Percentile：59.57(Nuclear Science & Technology)In the replacement period of a fusion power reactor, the assembly of blanket or divertor modules need to be removed from the reactor in order to minimize remote maintenance in the vacuum vessel and to attain a reasonable plant availability. In the hot cell, the modules will be removed from the backplate of the assembly. Here, note that the active cooling must be done by a way that does not cause contamination of the hot cell environment due to dispersion of tritium and tungsten dust. In this sense, the cooling scenario is adopted that the existing pipe of cooling water in the assembly is connected to a different cooling water system in the hot cell. In this scenario, the temperature of the assembly is maintained about 40-100
C. On the other hand, the structural material (RAFM) of the blanket and divertor is not recycled due to its high contact dose rate. It should be crushed into small pieces to reduce volume of the waste and required storage space. Here, the decay heat must be removed by natural convection to keep the temperature below 65C for preventing water evaporation from the mortar. The RAFM is kept in the interim storage during 12 years until the required temperature conditions for mortar are ensured and then is disposed of.
