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Hamaguchi, Takumi; Yamada, Junya; Komatsuzaki, Naoya*; Hatakeyama, Takumi; Seya, Natsumi; Muto, Yasunobu; Miyauchi, Hideaki; Hashimoto, Makoto
JAEA-Technology 2022-038, 65 Pages, 2023/03
JAEA-Technology-2022-038.pdf:4.3MB
New regulatory requirements were developed taking into account the lessons-learnt from the accident at Fukushima Daiichi Nuclear Power Station on March 2011. The new regulatory standards required that monitoring posts should be diversified in transmission systems and equipped with backup power supply equipment for design basis accidents. In this report, we look back on the history of monitoring posts in Oarai Research and Development Institute, explained the application for the permission of reactor installment license, application for approval of the design and construction method, pre-use operator's inspection and improvement design of monitoring posts. This report also includes about inspection based on act on special measures concerning nuclear emergency preparedness and the installation of KURAMA-II, which was carried out in conjunction with the improvement of monitoring post for new regulatory standards. As an appendix, application document for approval of the design and construction method are included.
Hamamoto, Shimpei; Shimizu, Atsushi; Inoi, Hiroyuki; Tochio, Daisuke; Homma, Fumitaka; Sawahata, Hiroaki; Sekita, Kenji; Watanabe, Shuji; Furusawa, Takayuki; Iigaki, Kazuhiko; et al.
Nuclear Engineering and Design, 388, p.111642_1 - 111642_11, 2022/03
Times Cited Count：2 Percentile：50.96(Nuclear Science & Technology)Following the Fukushima Daiichi Nuclear Power Plant accident in 2011, the Japan Atomic Energy Agency adapted High-Temperature engineering Test Reactor (HTTR) to meet the new regulatory requirements that began in December 2013. The safety and seismic classifications of the existing structures, systems, and components were discussed to reflect insights regarding High Temperature Gas-cooled Reactors (HTGRs) that were acquired through various HTTR safety tests. Structures, systems, and components that are subject to protection have been defined, and countermeasures to manage internal and external hazards that affect safety functions have been strengthened. Additionally, measures are in place to control accidents that may cause large amounts of radioactive material to be released, as a beyond design based accident. The Nuclear Regulatory Commission rigorously and appropriately reviewed this approach for compliance with the new regulatory requirements. After nine amendments, the application to modify the HTTR's installation license that was submitted in November 2014 was approved in June 2020. This response shows that facilities can reasonably be designed to meet the enhanced regulatory requirements, if they reflect the characteristics of HTGRs. We believe that we have established a reference for future development of HTGR.
Uesaka, Mitsuru*; Mineo, Hideaki
Nihon Genshiryoku Gakkai-Shi ATOMO
, 58(8), p.468 - 473, 2016/08
All the research reactors and critical assemblies (hereinafter RRCAs) in Japan are stopped in order to fulfil the new regulatory requirements, which were reinforced after the accident at the Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Station. These RRCAs have played important roles in the areas of human resource development, academic research, medical and industrial application of nuclear technology. Prolonged stoppage of RRCAs affects adversely those activities. Atomic Energy Society of Japan set up a group to discuss this issue. The group has shown a proposal that the roles of the RRCAs, which are indispensable facilities to nuclear human resource development, should be placed positively in the energy policy and the science and technology policy of the country.
Yamamoto, Masahiko; Shirozu, Hidetomo; Mori, Eito; Surugaya, Naoki
JAEA-Technology 2016-009, 58 Pages, 2016/05
JAEA-Technology-2016-009.pdf:3.95MB
The panels of glove box installed at Tokai Reprocessing Plant have been deteriorated and transparencies have been decreased due to the long-term use. Therefore, the panels have been replaced from the view point of preventive maintenance. In the new regulation formulated since the Fukushima Daiichi Nuclear Power Plant accident, it is demanded that the glove box consists of incombustible or inflammable materials. In this replacement, new panels have been manufactured with polycarbonate which satisfied the UL94 V-0 incombustible class. The inside of glove box has been contaminated with radioactive materials. Thus, the contamination and operator's exposure have been investigated. Then radiation protection equipment have been selected. Also, it is necessary to maintain the glove box enclosure during the replacement. The replacement has been conducted by covering the opening parts with vinyl sheets. The enclosure function has been verified by the inspection of the new panels and glove box.
Shimomura, Yusuke; Hanari, Akira*; Sato, Isamu*; Kitamura, Ryoichi
JAEA-Technology 2015-062, 47 Pages, 2016/03
JAEA-Technology-2015-062.pdf:1.85MB
In response to new standards for regulating waste management facilities, it was carried out impact assessment of forest fires on the waste management facilities existed in Oarai Research and Development Center of Japan Atomic Energy Agency. At first, a fire spread scenario of forest fires was assumed. The intensity of forest fires was evaluated from field surveys, forest fire evaluation models and so on. As models of forest fire intensity evaluation, Rothermel Model and Canadian Forest Fire Behavior Prediction (FBP) System were used. Impact assessment of radiant heat to the facilities was carried out, and temperature change of outer walls for the assumed forest fires was estimated. The outer wall temperature of facilities was estimated around 160
C at the maximum, it was revealed that it doesn't reach allowable temperature limit. Consequently, it doesn't influence the strength of concrete. In addition, a probability of fire breach was estimated to be about 20%. This report illustrates an example of evaluation of forest fires for the new regulatory standards through impact assessment of the forest fires on the waste management facilities.
Arai, Masaji; Wada, Shigeru; Murayama, Yoji
Proceedings of International Topical Meeting on Research Reactor Fuel Management and Meeting of the International Group on Reactor Research (RRFM/IGORR 2016) (Internet), p.403 - 408, 2016/03
In response to the accident at Fukushima Daiichi NPS, the new safety standards for research and test reactor facilities came into force on December 18, 2013. The evaluation of natural disasters and prevention of spread of accidents beyond design basis mainly were enhanced in the standards. We have completed the necessary checks and assessments, and submitted an application for reviewing if JRR-3 complies with the new standards to the Nuclear Regulation Authority on September 26, 2014.
Tamaki, Hitoshi
Tekisuto "Kakunenryo Saikuru" (Internet), 3 Pages, 2014/12
Revised regulatory rule of nuclear facilities in Japan defines "Serious accident", and require accident measures for them to not only power reactors, but also fuel reprocessing and fabrication facilities. This document describes the basis of accident measures for Serious accident at nuclear fuel reprocessing and fabrication facilities, as a part of "Text of Nuclear Fuel Cycle".
Nakamura, Hideo
no journal, ,
no abstracts in English
Nakai, Ryodai; Saito, Shinzo; Yamaguchi, Akira*; Okamoto, Koji*; Kani, Yoshio*
no journal, ,
In response to the lessons learned from the serious nuclear accidents at the TEPCO's Fukushima Daiichi Nuclear Power Stations, the report "Safety Requirements Expected to the Prototype Fast Breeder Reactor Monju" was issued taking into account the SFR specific safety characteristics. The report was reviewed by the leading international and domestic experts on SFR safety in order to obtain independent and objective evaluation. As a result the basic concept for prevention of severe accidents and mitigation of their consequences of Monju is appropriate in consideration of SFR specific safety characteristics, and is in accordance with international common understanding.
Yamamoto, Masaya; Saito, Hiroto; Itagaki, Wataru; Maeda, Shigetaka; Takamatsu, Misao
no journal, ,
Joyo is the main fast neutron irradiation facility to develop materials for nuclear industry in Japan. Toward restart, application for relicensing in accordance with newly established regulatory requirements is under discussion. After re-start, we would like to play a enhanced role of fast neutron irradiation experiments. In order to discuss with irradiation materials researchers, introduce the irradiation capabilities of Joyo after re-start.
Takeda, Masayasu; Shibayama, Mitsuhiro*
no journal, ,
no abstracts in English
Wada, Shigeru; Kawamura, Sho; Suzuki, Makoto; Kimura, Kazuya; Nagadomi, Hideki
no journal, ,
In 1990, JRR-3 was modified for upgrade and resumed its operation as a high performance and multi-purpose research reactor with thermal power of 20MW. Since modified, JRR-3 has been utilized for neutron beam experiments, neutron activation analysis, production of radioisotopes, neutron transmutation doping of silicon, fuel and material irradiation, etc. The maximum thermal power of JRR-3 is 20MW. JRR-3 is a light water moderated and cooled, pool type research reactor using low-enriched silicide fuel. JRR-3 had been confirmed conformation to new regulations on research and test reactor facilities which came into force on 18th December 2013. The application has been submitted to NRA on 26th September 2014. Finally, installment license of JRR-3 was permitted November in 2018. Restart the JRR-3 is planted in the few years.
Itagaki, Wataru; Saito, Hiroto; Yamamoto, Masaya; Takamatsu, Misao; Maeda, Shigetaka
no journal, ,
JAEA applied for inspections of Joyo under the new regulation on March 30, 2017. It is undergoing NRA's safety review against core modification to MK-IV 100 MW irradiation core, measurement to natural disaster and BDBAs. The MK-IV core will have the maximum fast neutron flux (E 
0.1 MeV) of 10
n/cm
s. This is a high-level fast neutron flux of the irradiation test facilities in the world. Joyo can further enhance its capabilities by tailoring neutron spectrum, decreasing or increasing the irradiation temperature. For an experiment, it is important to evaluate neutron flux, dpa and temperature. Joyo provides accurate evaluation of irradiation conditions based on calculations verified by previous characterization tests and measurement using dosimetry technique. In this presentation, measure to new regulation, schedule for restart and irradiation capability of Joyo are introduced.
Takeda, Masayasu; Murayama, Yoji
no journal, ,
no abstracts in English
Kimura, Kazuya; Araki, Masaaki; Nagadomi, Hideki; Wada, Shigeru
no journal, ,
no abstracts in English
Suzuki, Makoto; Kawamura, Sho; Kobayashi, Tetsuya; Horiguchi, Hironori; Wada, Shigeru
no journal, ,
no abstracts in English
Saito, Hiroto; Yamamoto, Masaya; Someya, Hiroyuki*; Itagaki, Wataru; Maeda, Shigetaka; Takamatsu, Misao
no journal, ,
Toward restart, the experimental fast reactor Joyo is now under the safety review by regulatory body. After restart, we would like to play a enhanced role of fast neutron irradiation experiments. In order to discuss with irradiation materials researchers, introduce the irradiation capabilities of Joyo after restart.
Hamamoto, Shimpei; Shimazaki, Yosuke; Nagasumi, Satoru; Tochio, Daisuke; Iigaki, Kazuhiko; Ishitsuka, Etsuo
no journal, ,
Regarding the countermeasures against accidents that may release a large amount of radioactive materials, which is one of the items of conformity review on the New Regulatory Requirements for HTTR (High temperature engineering test reactor), this presentation describes the concept of accident selection, the evaluation method and results of the reactor behavior at the time of the selected accident and the countermeasures to be taken at that time.
