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Okuno, Hiroshi; Kawakami, Takeshi; Watanabe, Fumitaka; Horikoshi, Hidehiko*
Journal of Disaster Research, 18(8), p.911 - 917, 2023/12
In response to residents' concerns about the radiation health effects following the nuclear accidents at the Fukushima Daiichi Nuclear Power Station of the Tokyo Electric Power Company in March 2011, the Japan Atomic Energy Agency (JAEA) established a telephone consultation system. Eight toll-free telephone lines were prepared, and employees with knowledge of radiation health effects were assigned for consultation. Approximately 35,000 consultations were conducted from March 17, 2011, to September 18, 2012. The results of the text mining analysis revealed that the greatest source of anxiety was the impact on children's health from radiation. The JAEA's system for telephone consultation was improved following this telephone consultation experience. The description of telephone hotlines in the International Atomic Energy Agency (IAEA) guide, GSG-14, was discussed for further improvements of the JAEA's telephone consultation system.
Takeuchi, Ryuji; Mikake, Shinichiro; Ikeda, Koki; Nishio, Kazuhisa*; Kokubu, Yoko; Hanamuro, Takahiro
JAEA-Review 2023-007, 114 Pages, 2023/07
JAEA-Review-2023-007.pdf:12.02MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center has been conducting the Mizunami Underground Research Laboratory (MIU) Project to enhance the reliability of geological disposal technologies through investigations of the deep geological environment in the crystalline rock (granite) at Mizunami City, Gifu Prefecture, central Japan since fiscal year 1996. Backfilling and restoration works in the MIU site have been being conducted based on "the MIU Project from FY2020 onwards" which is defined the way forward of backfilling and restoration works and environmental monitoring investigations in the MIU site, since fiscal year 2020. This report summarizes the outline, process, and achievements of the construction and the safety patrol of the backfilling and restoration works in the MIU site performed from May 16, 2020 to January 16, 2022.
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.
Nishio, Kazuhisa*; Hanamuro, Takahiro; Mikake, Shinichiro
JAEA-Review 2022-019, 42 Pages, 2022/08
JAEA-Review-2022-019.pdf:8.26MB
Research and development project, Mizunami Underground Research Laboratory (MIU) Project at the Tono Geoscience Center (TGC) of Japan Atomic Energy Agency (JAEA), has been performed since 1996 and ended in 2019 fiscal year. On January 14, 2022, construction work such as backfilling of the research tunnels of the MIU was also successfully completed. After the research results has been compiled, we decided to hold a final debriefing session to report the research results obtained from the project and the construction details such as backfilling of the tunnels. This report summarized the presentation materials used in "The Final Debriefing Session on the Mizunami Underground Research Laboratory Project" held on February 9, 2022.
Aihara, Jun; Kuroda, Masatoshi*; Tachibana, Yukio
Mechanical Engineering Journal (Internet), 9(4), p.21-00424_1 - 21-00424_13, 2022/08
It is important to improve oxidation resistance of fuel for huge oxygen ingress into core to improve safety of high temperature gas-cooled reactors (HTGRs), because almost volume of cores of HTGRs consist of graphite. In this study, simulated oxidation resistant fuel elements, of which matrix is mixture of SiC and graphite, has been fabricated by hot press method. In order to maintain structural integrity of fuel element under accident conditions, high-strength fuel elements should be developed. In order to identify optimal hot press conditions for preparing high-strength fuel elements, effect of hot press conditions on mechanical strength properties of fuel elements should be evaluated quantitatively. In the present study, response surface model, which represents relationship between hot press conditions and mechanical strength properties, has been constructed by introducing statistical design of experiments (DOE) approaches, and optimal hot press conditions were estimated by model.
Murakami, Masashi; Sasaki, Toshiki
JAEA-Review 2022-004, 106 Pages, 2022/06
JAEA-Review-2022-004.pdf:3.95MB
A numerous analytical data will be required for the characterization of the radioactive waste stored in Japan Atomic Energy Agency toward their processing and disposal. A "Data Quality Objectives (DQO) Process" is widely applied as a tool for the development of a cost-effective characterization plan in the overseas nuclear sites. The DQO Process is a multi-step planning process developed by the United States Environmental Protection Agency (EPA), and can be used for the planning of a scientifically rigorous and cost-effective data collection program for the various projects involving the collection of the environmental data. We have considered to reduce the cost required for the future characterization of the stored waste by applying the statistical methods and have performed a literature survey on the DQO Process. The survey effort was focused on the guidance documents of the DQO Process published by the EPA and was also spent for the related matters such as a quality system of the EPA and the activities beyond the DQO Process as well as the examples of the application at the nuclear sites. In this report, the details on the planning procedure using the DQO Process are reviewed together with the background information such as why DQO Process was developed, what kind of transition was occurred, and how it is currently used in the EPA. The examples on the application for various objects at Hanford Site in the United States, where has the various legacy waste generated in the past activities and has the big environmental problems, are also reviewed. This report summarizes the important matters and methodology on the planning with the statistical sampling methods. It also provides the examples of the approaches for the complex objects, and will therefore be helpful in the future planning for the various kind of the waste characterization.
Aihara, Jun; Kuroda, Masatoshi*; Tachibana, Yukio
Proceedings of 28th International Conference on Nuclear Engineering (ICONE 28) (Internet), 9 Pages, 2021/08
To maintain the structural integrity of fuel elements for a high-temperature gas-cooled reactor (HTGR) under disaster conditions, strong and oxidation-resistant fuel elements should be further developed. The HTGR fuel elements employ a hot-pressed silicon carbide (SiC)/carbon (C) mixed matrix to improve the oxidative resistance. Hot-press conditions such as pressure, temperature, and duration would be one of the factors that affect the strength of the HTGR fuel elements. To identify the optimal hot-press conditions for preparing the high-strength fuel elements, modelling their effects on the mechanical-strength properties of the HTGR fuel elements should be evaluated quantitatively. In this study, the response surface model, which represents the relationship between the hot-press conditions and the mechanical-strength properties, has been constructed by introducing statistical design-of-experiment approaches.
Takeishi, Minoru
JAEA-Review 2020-077, 388 Pages, 2021/05
JAEA-Review-2020-077.pdf:18.48MB
Japan Atomic Energy Agency (JAEA) have implemented environmental radiation monitoring since 1960s around different kinds of nuclear facilities such as research reactors, MOX fuel fabrication development facilities and the first spent fuel reprocessing facility for commercial NPPs and so on. I summarize the environmental monitoring methodology from planning to evaluation comprehensively as a guide book based on our experience and referring to the latest information. This guide book contained various basic knowledge about history of environmental radiation surveillances, techniques of radiation measurement and analysis of environmental samples such as airborne materials, precipitation, fallout, soil, sediment in river and lake, drinking water, terrestrial water, vegetables, milk, pasture, sea water, seabed sediment, marine product, index samples, and including with related to fundamental knowledges like an exposure evaluation for the public and quality assurance(QA), and some regulations. In particular, I include the emergency environmental radiation monitoring with response to the accident of Chernobyl Nuclear Power Plant and Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station. Finally, I note some topics on the environmental impact study that I have experienced.
Onoe, Hironori; Takeuchi, Ryuji
JAEA-Data/Code 2020-010, 112 Pages, 2020/10
JAEA-Data-Code-2020-010.pdf:6.22MBJAEA-Data-Code-2020-010-appendix1(DVD-ROM).zip:169.12MBJAEA-Data-Code-2020-010-appendix2(DVD-ROM).zip:338.45MBJAEA-Data-Code-2020-010-appendix3(DVD-ROM).zip:448.05MB
The Mizunami Underground Research Laboratory (MIU) Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), the project is being carried out under the Phase III. The main goals of the MIU Project from Phase I to Phase III are: to establish techniques for investigation, analysis and assessment of the deep geological environment, and to develop a base of engineering for deep underground application. One of the Phase III goals is to construct geological environment models and grasp deep geological changes when expanding the research gallery by research and investigations using research galleries. The long term hydro-pressure monitoring has been continued to achieve the Phase III goals. Furthermore, these monitoring were ceased at the end of FY2019 due to the completion of the MIU project. This report describes the results of the long term hydro-pressure monitoring from April 2017 to March 2020.
Semba, Takeshi
Nihon Genshiryoku Gakkai-Shi ATOMO
, 62(4), p.186 - 190, 2020/04
no abstracts in English
Okihara, Mitsunobu*; Yahagi, Ryoji*; Iwatsuki, Teruki; Takeuchi, Ryuji; Murakami, Hiroaki
JAEA-Technology 2019-021, 77 Pages, 2020/03
JAEA-Technology-2019-021.pdf:5.33MB
One of the major subjects of the ongoing geoscientific research program, the Mizunami Underground Research Laboratory (MIU) Project in the Tono area, central Japan, is accumulation of knowledge on monitoring techniques of the geological environment. In this report, the conceptual design of the monitoring system for groundwater pressure and water chemistry was carried out. The currently installed and used system in research galleries at various depths was re-designed to make it possible to collect groundwater and observe the water pressure on the ground.
Tamai, Hiroshi; Shimizu, Ryo; Tazaki, Makiko; Kimura, Takashi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusushu, p.89 - 92, 2019/11
Libya's denuclearisation, named "the Libya model", is regarded as one of good practices in cooperation of the international community and measures that have a sense of speed with the countries and institutions involved. Success factors of the denuclearisation are the Libya's relatively low technological progress despite the procurement of extensive nuclear materials and components due to the delay of detecting the nuclear programme, prompt implementation with the close collaboration of countries concerned, and Libya's cooperation facing to the economic sanctions and the regime collapse by the Iraq war. Precious lessons will be learned towards the prevention and the denuclearisation in other countries.
Sakai, Toshihiro; Matsuoka, Toshiyuki
JAEA-Data/Code 2019-007, 29 Pages, 2019/09
JAEA-Data-Code-2019-007.pdf:53.07MBJAEA-Data-Code-2019-007-appendix(CD-ROM).zip:340.04MB
Japan Atomic Energy Agency is performing the Horonobe Underground Research Laboratory Project, which includes a scientific study of the deep geological environment as a basis of research and development for the geological disposal of high level radioactive wastes, in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in the sedimentary rock. This report summarize numerical data of 3D geological model in regional-scale constructed by Maptek
Vulcan.
Shibayama, Mitsuhiro*; Murayama, Yoji; Takeda, Masayasu
AONSA Newsletter (Internet), 11(1), P. 20, 2019/08
no abstracts in English
Chiba, Yusuke; Nishiyama, Yutaka; Tsubaki, Hirohiko; Iwai, Masaki
JAEA-Technology 2019-002, 29 Pages, 2019/03
JAEA-Technology-2019-002.pdf:2.43MB
Act on Special Measures Concerning Nuclear Emergency Preparedness was amended on the 30th of October in 2017. As the JAEA Emergency Assistance Organization, Maintenance and Operation Section for Remote Control Equipment in Naraha Center for Remote Control Technology Development started training for emergency response robots operation for operators in each site of JAEA in response to the new amendment. The training consists of three operations: small crawler-type mobile scouting robots, big crawler-type mobile robots with a manipulator or a long tong and small radio-controlled helicopters. The training has three classes (beginner, intermediate and advanced classes) depending on skills and experiences. This paper reports the training programs of emergency response robots operation of the beginner and intermediate classes which were used in the first half of fiscal 2018.
Hanamuro, Takahiro
JAEA-Review 2018-011, 20 Pages, 2018/08
JAEA-Review-2018-011.pdf:2.77MB
As part of the research and development program on geological disposal of high-level radioactive waste (HLW), the Horonobe Underground Research Center, a division of the Japan Atomic Energy Agency (JAEA), is implementing the Horonobe Underground Research Laboratory Project (Horonobe URL Project) with the aim at investigating sedimentary rock formations. According to the research plan described in the 3rd Mid- and Long-term Plan of JAEA, according to the Horonobe URL Project, "Near-field performance study", "Demonstration of repository design option", and "Verification of crustal-movement buffering capacity of sedimentary rocks" are the top priority issues, and schedule for finishing the project and backfill plan will be decides by the end of 2019 Fiscal Year. The Horonobe URL Project is planned to extend over a period of about 20 years. This report summarizes the investigation program for the 2018 fiscal year (2018/2019).
Okano, Masanori; Akiyama, Kazuki; Taguchi, Katsuya; Nagasato, Yoshihiko; Omori, Eiichi
Dekomisshoningu Giho, (57), p.53 - 64, 2018/03
The construction of Tokai Reprocessing Plant (TRP) was initiated in June 1971, and its hot test using spent fuel started in September 1977. Thereafter TRP had been operated to reprocess 1,140 tons of spent fuel for approximately 30 years until May 2007, according to the reprocessing contract with domestic electric power companies. JAEA announced a policy of TRP in report of JAEA reform plan published in September 2014. The policy shows that TRP will shift to a decommissioning stage by economic reasons. Based on the policy, application of approval for TRP decommissioning plan was submitted to Nuclear Regulation Authority (NRA) in June 2017. This plan provides basic guidelines such as procedures for decommissioning and specific activities for risk reduction, and implementation divisions of decommissioning, management of spent fuels and radioactive wastes, decommissioning budget, and decommissioning schedule. The process of TRP decommissioning is planned to continue for approximately 70 years until the release of controlled areas of approximately 30 facilities.
Hama, Katsuhiro
Proceedings of 6th East Asia Forum on Radwaste Management Conference (EAFORM 2017) (Internet), 6 Pages, 2017/12
The Mizunami Underground Research Laboratory project is being pursued by the JAEA in the crystalline host rock at Mizunami City in Gifu Prefecture. The project proceeds in three overlapping phases, Surface-based investigation Phase (Phase I), Construction Phase (Phase II) and Operation Phase (III). During Phase I, a step-wise investigation was conducted by iterating investigation, interpretation, and assessment, thereby understanding of geologic environment was progressively and effectively improved with progress of investigation. During Phase II, we have evaluated adequacy of techniques for investigation, analysis and assessment of the deep geological environment established in the Phase I. For Phase III, three important issues were identified based on the latest results. Development of countermeasure technologies for reducing groundwater inflow, Development of modeling technologies for mass transport, Development of drift backfilling technologies.
Shirase, Mitsuyasu*; Abe, Akimasa*; Nago, Makito*; Ishii, Eiichi; Aoyagi, Kazuhei; Wakasugi, Shinichi*
Doboku Gakkai Heisei-29-Nendo Zenkoku Taikai Dai-72-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), p.1795 - 1796, 2017/09
JAEA has executed the underground facility construction operation from February 2011 to June 2014, while carrying out the maintenance and research project until 2018. This report is about the extra high head pump which was able to drain the high specific gravity grout drainage, which develops during grouting operation at this facility, directly from 250m underground to the surface.
Hama, Katsuhiro; Iwasaki, Riyo*; Morikawa, Keita*
JAEA-Technology 2017-015, 45 Pages, 2017/07
JAEA-Technology-2017-015.pdf:16.57MB
Tono Geoscience Center of Japan Atomic Energy Agency has been carrying out the Mizunami Underground Research Laboratory Project. The goal of mass transport study is to obtain a better understanding of mass transport phenomena in the geological environment as well as to develop technologies for measurement of the mass transport parameters, model construction, numerical analysis and validation of those technologies. This experiment was planned to understand the influence of the microscopic structure in the rock mass on the mass transport property. The diffusion experiment using rock sample was carried out. The macroscopic and microscopic observations were carried out to understand the distribution of tracer (uranine) after the diffusion experiment. The uranine was observed in the plagioclase, in the grain boundary and in the microfracture in the mineral grains. These results suggested that distribution of mineral and of microfracture could affect the diffusion property of uranine.
