Ito, Keita*; Yasutomi, Yoko*; Zhu, S.*; Nurmamat, M.*; Tahara, Masaki*; Toko, Kaoru*; Akiyama, Ryota*; Takeda, Yukiharu; Saito, Yuji; Oguchi, Tamio*; et al.
Physical Review B, 101(10), p.104401_1 - 104401_8, 2020/03
Kimura, Takashi; Tazaki, Makiko; Shimizu, Ryo; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.85 - 88, 2019/11
This is the summary of research result of methods for denuclearization and IAEA verification after the denuclearization in South Africa. South Africa had developed and possessed nuclear weapons, and dismantled them including the related facilities and equipment etc. by itself secretly in the past. The method for the denuclearization and the verification is unique in the world. This report could give us the lessons to investigate how to denuclearize and to verify them.
Tamai, Hiroshi; Shimizu, Ryo; Tazaki, Makiko; Kimura, Takashi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, 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.
Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.93 - 96, 2019/11
Iraq, defeated by the Gulf War, had to accept denuclearization under UN Security Council Resolution (UNSCR) 687, but did not immediately and accurately report all its past nuclear activities to the IAEA. IAEA, as an internationally authorized nuclear inspection and verification organization to Iraqi denuclearization by the UNSCR 687, gradually revealed existence and the whole picture of Iraqi clandestine nuclear activities and verified destruction of weapon related facilities and equipment as well as removal of nuclear materials outside Iraq. Analyzing Iraq's characteristics of denuclearization could serve as a good reference for not only preventing nuclear weapons development but also considering their denuclearization in current and future states.
Tazaki, Makiko; Kimura, Takashi; Shimizu, Ryo; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.81 - 84, 2019/11
South Africa had developed, manufactured, and possessed nuclear weapons, but later dismantled them all together with related facilities and equipment. After joining Treaty on the Non-Proliferation of Nuclear Weapons as a non-nuclear weapon state and concluding a Comprehensive Safeguards Agreement with the Atomic Energy Agency (IAEA), it started peaceful use of nuclear energy. In that sense, South Africa's denuclearization is one of good examples of past denuclearization in the world, although the South Africa's specific policy of apartheid had been deeply connected with its nuclear weapons development and denuclearization. Analysing South Africa's motivations for nuclear weapons development, incentives for denuclearization, and characteristics of its denuclearization could serve as a good reference for not only preventing nuclear weapons development but also considering their denuclearization in current and future states.
Shimizu, Ryo; Kimura, Takashi; Tazaki, Makiko; Nakatani, Takayoshi; Tamai, Hiroshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-40-Kai Nenji Taikai Puroshidhingusu, p.97 - 99, 2019/11
Despite international accusations, Iran pursued uranium enrichment capacity. But through unprecedented strong economic sanctions, Iran accepted the restrictions on uranium enrichment capacity and agreed to accept the additional protocol. Nuclear program of Iran and nuclear deal are good precedents for denuclearization that has solved peacefully through multilateral negotiations, its process and lessons are compiled.
Kono, Takashi*; Kakoki, Masaaki*; Yoshikawa, Tomoki*; Wang, X.*; Sumida, Kazuki*; Miyamoto, Koji*; Muro, Takayuki*; Takeda, Yukiharu; Saito, Yuji; Goto, Kazuki*; et al.
Physical Review B, 100(16), p.165120_1 - 165120_6, 2019/10
Yamashita, Shinichiro; Ioka, Ikuo; Nemoto, Yoshiyuki; Kawanishi, Tomohiro; Kurata, Masaki; Kaji, Yoshiyuki; Fukahori, Tokio; Nozawa, Takashi*; Sato, Daiki*; Murakami, Nozomu*; et al.
Proceedings of International Nuclear Fuel Cycle Conference / Light Water Reactor Fuel Performance Conference (Global/Top Fuel 2019) (USB Flash Drive), p.206 - 216, 2019/09
After the nuclear accident at Fukushima Daiichi Power Plant, research and development (R&D) program for establishing technical basis of accident-tolerant fuel (ATF) started from 2015 in Japan. Since then, both experimental and analytical studies necessary for designing a new light water reactor (LWR) core with ATF candidate materials are being conducted within the Japanese ATF R&D Consortium for implementing ATF to the existing LWRs, accompanying with various technological developments required. Until now, we have accumulated experimental data of the candidate materials by out-of-pile tests, developed fuel evaluation codes to apply to the ATF candidate materials, and evaluated fuel behavior simulating operational and accidental conditions by the developed codes. In this paper, the R&D progresses of the ATF candidate materials considered in Japan are reviewed based on the information available such as proceedings of international conference and academic papers, providing an overview of ATF program in Japan.
Yokoyama, Tatsunori; Kimura, Junichi*; Mitsuguchi, Takehiro; Danhara, Toru*; Hirata, Takafumi*; Sakata, Shuhei*; Iwano, Hideki*; Maruyama, Seiji*; Chang, Q.*; Miyazaki, Takashi*; et al.
Geochemical Journal, 52(6), p.531 - 540, 2018/12
Tazaki, Makiko; Tamai, Hiroshi; Shimizu, Ryo; Kimura, Takashi; Kitade, Yuta; Nakanishi, Hiroaki; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-39-Kai Nenji Taikai Rombunshu (Internet), 7 Pages, 2018/11
no abstracts in English
Nakanishi, Hiroaki; Kimura, Takashi; Shimizu, Ryo; Kitade, Yuta; Tazaki, Makiko; Tamai, Hiroshi; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-39-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2018/11
To extract the possible requirements for the Broader Conclusion (BC) drawn by the IAEA in the Member States, this study is to conduct the comparative analysis of the tendencies on the Member States from which the BC has been drawn and those from which the BC has not been drawn yet.
Kimura, Takashi; Tazaki, Makiko; Kitade, Yuta; Shimizu, Ryo; Tamai, Hiroshi; Nakanishi, Hiroaki; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-39-Kai Nenji Taikai Rombunshu (Internet), 5 Pages, 2018/11
This is the summary of research result of State Level Concept (SLC) which has been developed and conducted by the IAEA and a major purpose of the research reported here is to promote the nuclear operator's understandings for the importance of Broder Conclusion drawn continuously by the IAEA under SLC.
Kitade, Yuta; Tamai, Hiroshi; Tazaki, Makiko; Shimizu, Ryo; Kimura, Takashi; Nakanishi, Hiroaki; Suda, Kazunori
Nihon Kaku Busshitsu Kanri Gakkai Dai-39-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2018/11
Regional Safeguards is considered as one of the measures for strengthening IAEA safeguards and its concept is recognized at NPT Review Conference and also NSG Guidelines amended in 2011. This Study examines the elements for the proper establishment of Regional Safeguards.
Nakamura, Hironobu; Kimura, Takashi; Yamazaki, Katsuyuki; Kitao, Takahiko; Tasaki, Takashi; Iida, Toru
Proceedings of International Conference on Physical Protection of Nuclear Material and Nuclear Facilities (Internet), 9 Pages, 2018/09
After the accident of Fukushima Daiichi Nuclear Power Station, to develop effective security measures based on the lesson learned from such crisis and to meet the IAEA Nuclear Security Recommendations (INFCIRC/225/Rev.5), NRA in Japan made a partial amendment of the regulations concerning the reprocessing activity in 2012. The Tokai reprocessing facility implemented all of those security measures by the end of March 2014. Those new measures help us to keep high degree of security level and contributed to our planned operations to reduce the potential risk of the plant. On the other hand, the trustworthiness program was newly introduced in 2016, based on the trustworthiness policy determined by NRA. The implementing entity of the program is JAEA for the Tokai Reprocessing Facility and is required for both the persons afford unescorted access to Category I and II, CAS/SAS, and the persons afford access to the sensitive information. Those who are involved this program will be judged before engaging the work whether they might act as insider to cause or assist radiological sabotage or unauthorized removal of nuclear material, or leak sensitive information. The program is expected as a measure against insider at reprocessing facilities, and is expected to be enforced around the autumn of 2017. As well as the establishment of security measures, the promoting nuclear security culture for all employees was a big challenge. The Tokai reprocessing facility have introduced several security culture activities, such as case study education of security events done by a small group and putting up the security culture poster and so on. This paper presents introduction and implementation with effectiveness of security measures in the Tokai reprocessing facilities and the future security measures applied to the reprocessing facilities are discussed.
Nakamura, Hironobu; Kitao, Takahiko; Yamada, Hiroyuki; Kono, Soma; Kimura, Takashi; Tasaki, Takashi
Proceedings of INMM 59th Annual Meeting (Internet), 9 Pages, 2018/07
Takata, Fumiya*; Ito, Keita*; Takeda, Yukiharu; Saito, Yuji; Takanashi, Koki*; Kimura, Akio*; Suemasu, Takashi*
Physical Review Materials (Internet), 2(2), p.024407_1 - 024407_5, 2018/02
Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
Yamashita, Shinichiro; Nagase, Fumihisa; Kurata, Masaki; Nozawa, Takashi; Watanabe, Seiichi*; Kirimura, Kazuki*; Kakiuchi, Kazuo*; Kondo, Takao*; Sakamoto, Kan*; Kusagaya, Kazuyuki*; et al.
Proceedings of 2017 Water Reactor Fuel Performance Meeting (WRFPM 2017) (USB Flash Drive), 10 Pages, 2017/09
In Japan, the research and development (R&D) project on accident tolerant fuel and other components (ATFs) of light water reactors (LWRs) has been initiated in 2015 for establishing technical basis of ATFs. The Japan Atomic Energy Agency (JAEA) has coordinated and carried out this ATF R&D project in cooperation with power plant providers, fuel venders and universities for making the best use of the experiences, knowledges in commercial uses of zirconium-base alloys (Zircaloy) in LWRs. ATF candidate materials under consideration in the project are FeCrAl steel strengthened by dispersion of fine oxide particles(FeCrAl-ODS) and silicon carbide (SiC) composite, and are expecting to endure severe accident conditions in the reactor core for a longer period of time than the Zircaloy while maintaining or improving fuel performance during normal operations. In this paper, the progresses of the R&D project are reported.
Yano, Yasuhide; Tanno, Takashi; Oka, Hiroshi; Otsuka, Satoshi; Inoue, Toshihiko; Kato, Shoichi; Furukawa, Tomohiro; Uwaba, Tomoyuki; Kaito, Takeji; Ukai, Shigeharu*; et al.
Journal of Nuclear Materials, 487, p.229 - 237, 2017/04
Ultra-high temperature ring tensile tests were carried out to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions; temperatures ranged from room temperature to 1400C which is near the melting point of core materials. The experimental results showed that tensile strength of 9Cr-ODS steel claddings was highest in the core materials at the ultra-high temperatures between 900 and 1200C, but that there was significant degradation in tensile strength of 9Cr-ODS steel claddings above 1200C. This degradation was attributed to grain boundary sliding deformation with / transformation, which was associated with reduced ductility. On the other hand, tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 C unlike the other tested materials. Present study includes the result of "R&D of ODS ferritic steel fuel cladding for maintaining fuel integrity at the high temperature accident condition" entrusted to Hokkaido University by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).
Uwaba, Tomoyuki; Yano, Yasuhide; Otsuka, Satoshi; Naganuma, Masayuki; Tanno, Takashi; Oka, Hiroshi; Kato, Shoichi; Kaito, Takeji; Ukai, Shigeharu*; Kimura, Akihiko*; et al.
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04
Tolerance of fast rector fuel elements to failure in the typical accident conditions was evaluated for the oxide-dispersion-strengthened (ODS) ferritic steel claddings that are candidate of the cladding material for advanced fast reactors. The evaluation was based on the cladding creep damage, which was quantified by the cumulative damage fractions (CDFs). It was shown that the CDFs of the ODS ferritic steel cladding were substantially lower than the breach limit of 1.0 in the loss of flow and transient over power conditions until a passive reactor shutdown system operates.