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Torii, Tatsuo; Sanada, Yukihisa
Introduction to Environmental Radioactivity, p.31 - 54, 2024/02
no abstracts in English
Nuclear Emergency Assistance and Training Center
JAEA-Review 2023-026, 54 Pages, 2023/12
JAEA-Review-2023-026.pdf:3.26MB
The Japan Atomic Energy Agency (JAEA) is one of the designated public corporations, which is the agency dealing with emergency situations in cooperation with the Japanese and local governments under the Disaster Countermeasures Basic Act and under the Armed Attack Situation Response Law. JAEA has, therefore, responsibilities of providing technical assistances to the Japanese and local governments in case of nuclear or radiological emergencies based on these acts. To fulfill the assistances, the JAEA has prepared the Nuclear Emergency Support Measures Regulation, Disaster Prevention Work Plan and Civil Protection Work Plan. The Nuclear Emergency Assistance and Training Center (NEAT) is the main center of the technical assistance in case of emergency, and dispatches experts of JAEA, supplies equipment and materials and gives technical advice and information, to the Japanese and local governments for emergency based on the regulation and plans. In normal time, the NEAT provides the technical assistances such as the exercises and training courses concerning the nuclear preparedness and response to the JAEA experts and to emergency responders including the Japanese and local government officers. This report introduces the results of activities in Japanese Fiscal Year 2022, conducted by the NEAT.
Zr + d reaction cross sections measured at 28 MeV/nucleonChillery, T.*; Hwang, J.*; Dozono, Masanori*; Imai, Nobuaki*; Michimasa, Shinichiro*; Sumikama, Toshiyuki*; Chiga, Nobuyuki*; Ota, Shinsuke*; Nakayama, Shinsuke; 49 of others*
Progress of Theoretical and Experimental Physics (Internet), 2023(12), p.121D01_1 - 121D01_11, 2023/12
Times Cited Count：0 Percentile：0.01(Physics, Multidisciplinary)The deuteron is a loosely bound system which can easily break up into its constituent proton and neutron whilst in the presence of Coulomb and nuclear fields. Previous experimental studies have shown that this breakup process has a significant impact on residual nucleus production from deuteron bombardment in the high energy range of 50 - 210 MeV/nucleon. However, there remains a lack of cross-section data at energies below 50 MeV/nucleon. The current study determined Zr + d reaction cross sections under inverse kinematics at approximately 28 MeV/nucleon using the BigRIPS separator, OEDO beamline, and SHARAQ spectrometer. Cross sections from this research were compared with previous measurements and theoretical calculations. The experimental results show a large enhancement of the production cross sections of residual nuclei, especially those produced from a small number of particle emissions, compared to the proton-induced reaction data at similar bombarding energy. The DEURACS calculation, which quantitatively takes deuteron-breakup effects into account, reproduces the data well. As a long-lived fission product, Zr remains a challenge for nuclear waste disposal and treatment. This study's low-energy data may assist future consideration of nuclear-waste treatment facilities, where Zr + d may feasibly transmute the waste into short-lived/stable nuclei.
Akiyama, Yoichi; Shibanuma, So; Yanagisawa, Kenichi*; Yamada, Taichi; Suzuki, Kenta; Yoshida, Moeka; Ono, Takahiro; Kawabata, Kuniaki; Watanabe, Kaho; Morimoto, Kyoichi; et al.
JAEA-Review 2023-015, 60 Pages, 2023/09
JAEA-Review-2023-015.pdf:4.78MB
Naraha Center for Remote Control Technology Development (NARREC) was established in Japan Atomic Energy Agency to promote a decommissioning work of Fukushima Daiichi Nuclear Power Station (Fukushima Daiichi NPS). NARREC consists of a Full-scale Mock-up Test Building and Research Management Building. Various test facilities are installed in these buildings for the decommissioning work of Fukushima Daiichi NPS. These test facilities are intended to be used for various users, such as companies engaged in the decommissioning work, research and development institutions, educational institutions and so on. The number of NARREC facility uses was 84 in FY2021. We participated booth exhibitions and presentations on the decommissioning related events. Moreover, we also contributed to the development of human resources by supporting the 6th Creative Robot Contest for Decommissioning. As a new project, "Narahakko Children's Classroom" was implemented for elementary school students in Naraha Town. This report summarizes the activities of NARREC in FY2021, such as the utilization of facilities and equipment of NARREC, the development of remote-control technologies for supporting the decommissioning work, arrangement of the remote-control machines for emergency response, and training for operators by using the machines.
Nakazawa, Osamu; Takiya, Hiroaki; Murakami, Masashi; Donomae, Yasushi; Meguro, Yoshihiro
JAEA-Review 2023-012, 6 Pages, 2023/08
JAEA-Review-2023-012.pdf:0.93MB
The selection of back-end technology development issues to be prioritized and their schedule of the Japan Atomic Energy Agency (JAEA) have been put together as the "Strategic Roadmap for Back-end Technology Development." The results of questionnaires on development technologies (seeds) and technical issues (needs) within JAEA conducted in FY2022 were reflected in the selection. The issues were extracted from among those that match the seeds and needs, from the perspective of early implementation in the work front and the perspective of common issues, and nine themes were selected. We will build a cross-organizational implementation framework within JAEA and aim to implement the development results in the work front as well as social implementation.
Watanabe, Kazuki; Kimura, Norimichi*; Okada, Jumpei; Furuuchi, Yuta; Kuwana, Hideharu*; Otani, Takehisa; Yokota, Satoru; Nakamura, Yoshinobu
JAEA-Technology 2023-010, 29 Pages, 2023/06
JAEA-Technology-2023-010.pdf:3.12MB
The Krypton Recovery Development Facility reached an intended technical target (krypton purity of over 90% and recovery rate of over 90%) by separation and rectification of krypton gas from receiving off-gas produced by the shearing and the dissolution process in the spent fuel reprocessing at the Tokai Reprocessing Plant (TRP) between 1988 and 2001. In addition, the feasibility of the technology was confirmed through immobilization test with ion-implantation in a small test vessel from 2000 to 2002, using a part of recovered krypton gas. As there were no intentions to use the remaining radioactive krypton gas in the krypton storage cylinders, we planned to release this gas by controlling the release amount from the main stack, and conducted it from February 14 to April 26, 2022. In this work, all the radioactive krypton gas in the cylinders (about 7.1
10
GBq) was released at the rate of 50 GBq/min or less lower than the maximum release rate from the main stuck stipulated in safety regulations (3.710
GBq/min). Then, the equipment used in the controlled release of radioactive krypton gas and the main process (all systems, including branch pipes connected to the main process) were cleaned with nitrogen gas. Although there were delays due to weather, we were able to complete the controlled release of radioactive krypton gas by the end of April 2022, as originally targeted without any problems such as equipment failure.
Tsuchiya, Kunihiko
Nihon Genshiryoku Gakkai-Shi ATOMO
, 65(6), p.393 - 397, 2023/06
no abstracts in English
Saito, Shigeru; Yamaguchi, Kazushi*; Yoshimoto, Hidemitsu*; Obayashi, Hironari; Sasa, Toshinobu
JAEA-Technology 2022-032, 51 Pages, 2023/03
JAEA-Technology-2022-032.pdf:4.51MB
In the Accelerator Driven System (ADS) being studied by the Japan Atomic Energy Agency (JAEA) for transmutation of long-lived radioactive waste, lead-bismuth eutectic alloy (LBE) is used as a spallation target and subcritical core coolant. A proton irradiation facility in J-PARC is considered to prepare a material irradiation database for ADS development. The proton irradiation facility is equipped with an LBE loop, which enables material irradiation tests in spallation environment under flowing LBE condition. The slow leakage of LBE is one of critical issue to use LBE safety. The slow leakage is caused by the biting slag and/or other materials at valve seal of drain valve. To solve this problem, JAEA examined the application of freeze-seal valve (FSV), which seal the piping by freezing LBE in specific position. Water-cooled and air-cooled freeze-seal valve test modules were fabricated, installed in the test section of the existing test stand for LBE technology development, and tested to confirm their operation and performance. As a result of the tests, it was confirmed that the water-cooled FSV test module worked well along to the design values. This report describes the outline and details of the test stand for LBE technology and each FSV test module, as well as the results of operation and performance verification tests.
Maekawa, Fujio
Ryoshi Bimu Kagaku No Kiso To Oyo; NSA/Commentaries, No.27, p.15 - 25, 2023/03
The nuclear transmutation technology that is one of the most beneficial industrial applications of quantum beams to humankind is explained.
Nuclear Science and Engineering Center; Fuel Cycle Design Office; Plutonium Fuel Development Center; Nuclear Plant Innovation Promotion Office; Fast Reactor Cycle System Research and Development Center; J-PARC Center
JAEA-Review 2022-052, 342 Pages, 2023/02
JAEA-Review-2022-052.pdf:18.05MB
This report summarizes the current status and future plans of research and development (R&D) on partitioning and transmutation technology in Japan Atomic Energy Agency, focusing on the results during the 3rd Medium- to Long-term Plan period (FY 2015-2021). Regarding the partitioning technology, R&D of the solvent extraction method and the extraction chromatography method are described, and regarding the minor actinide containing fuel technology, R&D of the oxide fuel production using the simplified pellet method, the nitride fuel production using the external gelation method, and pyrochemical reprocessing of the nitride fuel were summarized. Regarding transmutation technology, R&D of technology using fast reactors and accelerator drive systems were summarized. Finally, the new facilities necessary for the future R&D were mentioned.
Nakano, Hiroko; Nishikata, Kaori; Nagata, Hiroshi; Ide, Hiroshi; Hanakawa, Hiroki; Kusunoki, Tsuyoshi
JAEA-Review 2022-073, 23 Pages, 2023/01
JAEA-Review-2022-073.pdf:2.02MB
A practical training course using the JMTR (Japan Materials Testing Reactor) and other research infrastructures was held from July 24th to July 31st in 2019 for Asian young researchers and engineers. This course was adopted as Japan-Asia Youth Exchange Program in Science (SAKURA Exchange Program in Science) which is the project of the Japan Science and Technology Agency, and this course aims to enlarge the number of high-level nuclear researchers/engineers in Asian countries which are planning to introduce a nuclear power plant, and to promote the use of facilities in future. In this year, 12 young researchers and engineers joined the course from 6 countries. This course consists of lectures, which are related to irradiation test research, safety management of nuclear reactors, nuclear characteristics of the nuclear reactors, etc., practical training such as practice of research reactor operation using simulator and technical tour of nuclear facilities on nuclear energy. The content of this course in FY 2019 is reported in this paper.
Nuclear Emergency Assistance and Training Center
JAEA-Review 2022-044, 58 Pages, 2022/12
JAEA-Review-2022-044.pdf:3.83MB
The Japan Atomic Energy Agency (JAEA) is one of the designated public corporations, which is the agency dealing with emergency situations in cooperation with the Japanese and local governments under the Disaster Countermeasures Basic Act and under the Armed Attack Situation Response Law. JAEA has, therefore, responsibilities of providing technical assistances to the Japanese and local governments in case of nuclear or radiological emergencies based on these acts. To fulfill the assistances, the JAEA has prepared the Nuclear Emergency Support Measures Regulation, Disaster Prevention Work Plan and Civil Protection Work Plan. The Nuclear Emergency Assistance and Training Center (NEAT) is the main center of the technical assistance in case of emergency, and dispatches experts of JAEA, supplies equipment and materials and gives technical advice and information, to the Japanese and local governments for emergency based on the regulation and plans. In normal time, the NEAT provides the technical assistances such as the exercises and training courses concerning the nuclear preparedness and response to the JAEA experts and to emergency responders including the Japanese and local government officers. This report introduces the results of activities in Japanese fiscal year 2021, conducted by the NEAT.
Geological Disposal Research and Development Department
JAEA-Evaluation 2022-007, 81 Pages, 2022/11
JAEA-Evaluation-2022-007.pdf:2.06MB
JAEA-Evaluation-2022-007-appendix(CD-ROM).zip:37.06MB
Japan Atomic Energy Agency (JAEA) consulted the advisory committee, "Evaluation Committee on Research and Development (R&D) Activities for Geological Disposal of High-Level Radioactive Waste", for post- and pre-review assessment of R&D activities on high-level radioactive waste disposal in accordance with "General Guideline for the Evaluation of Government Research and Development (R&D) Activities" by the Cabinet Office, Government of Japan, "Guideline for Evaluation of R&D in Ministry of Education, Culture, Sports, Science and Technology" and JAEA's "Regulation on Conduct for Evaluation of R&D Activities". In response to JAEA's request, the Committee reviewed mainly the progress of the R&D project on geological disposal, the relevance of the project outcome and the efficiency of the project implementation during the period of the current and next plan. This report summarizes the results of the assessment by the Committee with the Committee report attached.
Tazaki, Makiko; Nakatani, Takayoshi; Shimizu, Ryo; Kimura, Takashi; Hori, Masato
Dai-43-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2022/11
Denuclearization consists of (1) verification of nuclear activities prior to denuclearization, (2) freeze, disablement and decommissioning of nuclear weapons, nuclear materials such as HEU and Pu, their production facilities, including facilities and equipment, and their verification. In this study, as a premise for the denuclearization of nuclear materials and nuclear facilities, and with reference to the results of previous denuclearization case surveys and related literature, the denuclearization process and its options for technical measures are discussed and considered.
Nagatani, Taketeru; Sagara, Hiroshi*; Kosuge, Yoshihiro*; Nakaguki, Sho; Nomi, Takayoshi; Okumura, Keisuke
Dai-43-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 3 Pages, 2022/11
Naraha Center for Remote Control Technology Development, Fukushima Research Insitute
JAEA-Review 2022-021, 40 Pages, 2022/09
JAEA-Review-2022-021.pdf:2.54MB
Naraha Center for Remote Control Technology Development (NARREC) was established in Japan Atomic Energy Agency to promote a decommissioning work of Fukushima Daiichi Nuclear Power Station (Fukushima Daiichi NPS). NARREC consists of a Full-scale Mock-up Test Building and Research Management Building. Various test facilities are installed in these buildings for the decommissioning work of Fukushima Daiichi NPS. These test facilities are intended to be used for various users, such as companies engaged in the decommissioning work, research and development institutions, educational institutions and so on. The number of NARREC facility uses was 69 in FY2020. We participated booth exhibitions and presentations on the decommissioning related events. Moreover, we also contributed to the development of human resources by supporting the 5th Creative Robot Contest for Decommissioning on online because of the COVID-19. This report summarizes the activities of NARREC in FY2020, such as the utilization of facilities and equipment of NARREC, the development of remote control technologies for supporting the decommissioning work, arrangement of the remote control machines for emergency response, and training for operators by using the machines.
Tamai, Hiroshi
Nihon Genshiryoku Gakkai-Shi ATOMO, 64(8), p.465 - 467, 2022/08
Though nuclear safety and nuclear security share the same goal of protecting the public and the environment from the harmful effects of ionizing radiation, their response actions may have differences, especially during transport, where protection could be vulnerable. The interface between them is a major issue. In December 2021, with the aim of complementarily strengthening nuclear safety and nuclear security in the transportation of radioactive materials IAEA published a related technical report and held an international conference. The outline of the technical report and the international conference is introduced.
Yamaguchi, Masaaki
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 29(1), p.38 - 41, 2022/06
This presentation outlined the framework and background of Japan's geological disposal research that has been underway since the 1970s and outlined research and development on the engineering technology of geological disposal and the performance assessment of geological disposal systems in the research and development fields. Specific assessment methods used in both R & D fields and recent research topics were also explained.
Fuwa, Yasuhiro; Iwashita, Yoshihisa*; Kondo, Akihiro*
IEEE Transactions on Applied Superconductivity, 32(6), p.4007304_1 - 4007304_4, 2022/06
Times Cited Count：0 Percentile：0(Engineering, Electrical & Electronic)High-field magnets are often demanded advanced scientific studies. Although a hybrid coil design comprising Nb-Ti, Nb
Sn, and HTS (High-Temperature Superconductors) are potential candidates for such application, the costs of NbSn and HTS are expensive compared with Nb-Ti. By generating an additional field of about 1 T by permanent magnets, the required amounts of superconducting material may be reduced. Magnetic properties of some magnetic materials have been studied by other works at temperatures as low as 100 K. The remanent field of conventional NdFeB magnets decreases at 100 K due to spin reorientation. PrFeB magnets consisting of praseodymium (Pr) instead of neodymium (Nd) do not show such degradation and the coercivity of PrFeB at 100 K is 7 T. In this study, the B-H curve, as a primary magnetic property, of a PrFeB magnet sample was measured in the temperature range down to 4 K. As a result, no decrease in magnetization of the praseodymium magnets, and the coercivity was 10 T.
Kureta, Masatoshi
Ryutai Keisokuho; Kaitei-Han, p.367 - 371, 2022/04
The Japan Society of Mechanical Engineers publishes a revised version of the technical document summarizing fluid measurement techniques. This article is part of the application section, and the main content is an introduction of application examples using advanced thermal-fluid measurement technology that is progressing remarkably. In the chapter "Void Fraction Distribution Measurement", the technology for visualizing and measuring the void fraction distribution with neutron beams for the two-phase flow of gas-liquid flowing inside the instrument is summarized. In the first half, the definition of void fraction, measurement by neutron transmission method, and basic principles of CT imaging technology were explained. In the second half, visualization and measurement results were shown in the order of two-dimensional and two-dimensional time changes of various multiphase flows, and three-dimensional and three-dimensional time changes.
