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Koyama, Shinichi; Nakagiri, Toshio; Osaka, Masahiko; Yoshida, Hiroyuki; Kurata, Masaki; Ikeuchi, Hirotomo; Maeda, Koji; Sasaki, Shinji; Onishi, Takashi; Takano, Masahide; et al.
Hairo, Osensui Taisaku jigyo jimukyoku Homu Peji (Internet), 144 Pages, 2021/08
JAEA performed the subsidy program for the "Project of Decommissioning and Contaminated Water Management (Development of Analysis and Estimation Technology for Characterization of Fuel Debris (Development of Technologies for Enhanced Analysis Accuracy and Thermal Behavior Estimation of Fuel Debris))" in 2020JFY. This presentation summarized briefly the results of the project, which will be available shortly on the website of Management Office for the Project of Decommissioning and Contaminated Water Management.
Kato, Atsushi; Chikazawa, Yoshitaka; Nabeshima, Kunihiko; Iwasaki, Mikinori*; Akiyama, Yo*; Oya, Takeaki*
Proceedings of 2015 International Congress on Advances in Nuclear Power Plants (ICAPP 2015) (CD-ROM), p.593 - 600, 2015/05
Japan sodium cooled fast reactor is the advanced loop type reactor developing in Japan. After the Fukushima-Dai-ichi NPP accident, system enhancement against severe accident have been investigated mainly for residual decay heat removal system, spent fuel storage system and emergency power sources in order to satisfy the safety design criteria for Generation IV SFR. This paper describes principle of the building layout design and the actual approach to be consistent with the recent design enhancement in JSFR. From the perspective of greater ability to withstand severe events, the principles of the building layout design as the measures against aircraft attack and the consequential fire, and tsunami are introduced in order to avoid local event initiating and simultaneous redundant failure of the safety grade facilities and could achieve lowering risk of the loss of all stuck and maintaining the essential power supply.
Sato, Takeshi; Muto, Shigeo; Akiyama, Kiyomitsu; Aoki, Kazufumi; Okamoto, Akiko; Kawakami, Takeshi; Kume, Nobuhide; Nakanishi, Chika; Koie, Masahiro; Kawamata, Hiroyuki; et al.
JAEA-Review 2014-048, 69 Pages, 2015/02
JAEA-Review-2014-048.pdf:13.91MB
JAEA was assigned as a designated public institution under the Disaster Countermeasures Basic Act and under the Armed Attack Situations Response Act. Based on these Acts, the JAEA has the responsibility of providing technical support to the national government and/or local governments in case of disaster responses or response in the event of a military attack, etc. In order to fulfill the tasks, the JAEA has established the Emergency Action Plan and the Civil Protection Action Plan. In case of a nuclear emergency, NEAT dispatches specialists of JAEA, supplies the national government and local governments with emergency equipment and materials, and gives technical advice and information. In normal time, NEAT provides various exercises and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response institutions of the national and local governments, police, fire fighters, self-defense forces, etc. in addition to the JAEA itself. The NEAT also researches nuclear disaster preparedness and response, and cooperates with international organizations. In the FY2013, the NEAT accomplished the following tasks: (1) Technical support activities as a designated public institution in cooperation with the national and local governments, etc. (2) Human resource development, exercise and training of nuclear emergency response personnel for the national and local governments, etc. (3) Researches on nuclear disaster preparedness and response, and sending useful information (4) International contributions to Asian countries on nuclear disaster preparedness and response in collaboration with the international organizations
Sato, Takeshi; Muto, Shigeo; Okuno, Hiroshi; Katagiri, Hiromi; Akiyama, Kiyomitsu; Okamoto, Akiko; Koie, Masahiro; Ikeda, Takeshi; Nemotochi, Toshimasa; Saito, Toru; et al.
JAEA-Review 2013-046, 65 Pages, 2014/02
JAEA-Review-2013-046.pdf:11.18MB
When a nuclear emergency occurs in Japan, the Japan Atomic Energy Agency (JAEA) has the responsibility of providing technical support to the National government, local governments, police, fire stations and nuclear operators etc., because the JAEA has been designated as the Designated Public Institution under the Basic Act on Disaster Control Measures and the Act on Response to Armed Attack Situations, etc.. The Nuclear Emergency Assistance and Training Center (NEAT) of JAEA provides a comprehensive range of technical support activities to an Off-Site Center in case of a nuclear emergency. Specifically, NEAT gives technical advice and information, dispatches specialists as required, and supplies the National Government and local governments with emergency equipments and materials. NEAT provides various exercise and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response organizations at normal times. The tasks of NEAT, with its past experiences as a designated public institution including the responses to TEPCO's Fukushima Accident, have been shifted to technical supports to the national government for strengthening its abilities to emergency responses; the NEAT therefore focused on maintenance and operation of its functions, and strengthening its response abilities in cooperation with the national government. This annual report summarized these activities of JAEA/NEAT in the fiscal year 2012.
Yamamoto, Tomohiko; Kato, Atsushi; Chikazawa, Yoshitaka; Ito, Kei; Iwasaki, Mikinori*; Akiyama, Yo*; Oya, Takeaki*
Proceedings of 2013 International Congress on Advances in Nuclear Power Plants (ICAPP 2013) (USB Flash Drive), 9 Pages, 2013/04
The Japan sodium-cooled fast reactor (JSFR) is planning to adopt a steel-plate reinforced concrete (SC) structure reactor building and an advanced seismic isolation system for reactor building. In the response of Fukushima Dai-ichi Nuclear Power Plant (Fukushima I NPP) accident, the evaluation and countermeasure study of earthquake, and other external hazards on JSFR has been analyzed based on 2010 JSFR design. This paper describes the detail of evaluation and countermeasure of earthquake, tsunami and other external hazards to JSFR reactor building.
Kato, Atsushi; Chikazawa, Yoshitaka; Yamamoto, Tomohiko; Ohno, Shuji; Kubo, Shigenobu; Sakaba, Hiroshi*; Akiyama, Yo*; Iwasaki, Mikinori*
Proceedings of 2013 International Congress on Advances in Nuclear Power Plants (ICAPP 2013) (USB Flash Drive), 9 Pages, 2013/04
After the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Plant, evaluations of severe events beyond the design basis on a NPP are focused. As one of those activities, wide range of sodium combustion and hydrogen generation potentials have been analyzed to investigate potential consequences on SCCV. Structural and boundary integrity of SCCV have been evaluated from sodium combustion analyses for pressure and temperature loads. Hydrogen generation has also been evaluated as potential loads of SCCV.
Yamamoto, Tomohiko; Kato, Atsushi; Chikazawa, Yoshitaka; Oya, Takeaki*; Iwasaki, Mikinori*; Hara, Hiroyuki*; Akiyama, Yo*
Proceedings of 2012 International Congress on Advances in Nuclear Power Plants (ICAPP '12) (CD-ROM), p.500 - 508, 2012/06
Japan Sodium-cooled Fast Reactor (JSFR) is planning to adopt the new concepts of reactor building. One is that the steel plate reinforced concrete is adopted for containment vessel and reactor building. The other is the advanced seismic isolation system. This paper describes the detail of new concepts for JSFR reactor building and engineering evaluation of the new concepts.
Kato, Atsushi; Negishi, Kazuo; Yamamoto, Tomohiko; Akiyama, Yo*; Hara, Hiroyuki*; Iwasaki, Mikinori*
Transactions of the 21st International Conference on Structural Mechanics in Reactor Technology (SMiRT-21) (CD-ROM), 8 Pages, 2011/11
Japan Sodium-cooled Fast Reactor (JSFR) adopts a new concept of a containment vessel called steel plate reinforced concrete containment vessel (SCCV). The SCCV is considered to be effective to shorten construction period thanks for elimination of rebar work at a site compared with applying the reinforced concrete CV. Other than this advantage, the SCCV achieves high quality in building structure, since steel structure parts can be fabricated at a factory prior to the site construction. Although the SC structure has been used for the buildings of LWR etc, it is important to investigate its characteristics under high temperature to adopt the SC structure to the JSFR CV. This paper mainly describes the design study and experiments to investigate potential characteristics of the SC structure under hypothetical sodium combustion in the CV.
Kato, Atsushi; Negishi, Kazuo; Akiyama, Yo*; Hara, Hiroyuki*
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 10 Pages, 2011/10
Japan Sodium-Cooled Fast Reactor (JSFR) adopts new concept of containment vessel called steel plate reinforced concrete containment vessel (SCCV). The SCCV is considered to be effective to shorten construction schedule due to elimination of rebar work at a site and so on. Although the SC structure has been used for the buildings of LWR etc, it is important to investigate its characteristics under temperature load to adopt as the containment vessel. This paper describes experimental investigations of characteristics of the SC structure under 700 centigrade(
C) at the surface steel plate which is decided assuming hypothetical sodium combustion in the containment vessel to study the potential strength of the SC structure.
Kato, Atsushi; Negishi, Kazuo; Akiyama, Yo*; Kubo, Shigenobu*
Dai-15-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.231 - 232, 2010/06
Reduction of plant construction cost is one of the most important issues for commercialization of fast reactors. From this point of view, an innovative containment vessel adopting steel plate reinforced concrete structure (SCCV) is developed for Japan Sodium-cooled Fast Reactor (JSFR). Although SC structure is generally in practical use, performance after exposing high temperature is not investigated. An experimental study including loading and/or heating tests has been carried out to investigate the fundamental structural features, which would be provided to develop methodology to evaluate the feasibility of SCCV under the severe conditions. In this paper, the design feature, the design and evaluation conditions for SCCV of JSFR as well as the construction method are summarized.
Kasamatsu, Yoshitaka*; Toyoshima, Atsushi; Asai, Masato; Tsukada, Kazuaki; Li, Z.; Ishii, Yasuo; Tome, Hayato*; Sato, Tetsuya; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.
Chemistry Letters, 38(11), p.1084 - 1085, 2009/10
Times Cited Count：15 Percentile：48.93(Chemistry, Multidisciplinary)We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z = 105 in HF/HNO
solution at the fluoride ion concentration [F
] = 0.003 M. The result clearly demonstrates that the fluoro complex formation of Db is significantly different from that of the group-5 homologue Ta in the 6th period of the periodic table while the behavior of Db is similar to that of the lighter homologue Nb in the 5th period.
Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.
Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10
J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.
) by laser ablation in superfluid helium at 1.5KAratono, Yasuyuki; Wada, Akira*; Akiyama, Kazuhiko; Kitazawa, Shinichi; Hojo, Kiichi; Naramoto, Hiroshi*
Chemical Physics Letters, 408(4-6), p.247 - 251, 2005/06
Times Cited Count：1 Percentile：3(Chemistry, Physical)C fulleren was detected in the deposit produced by the laser ablation in superfluid helium at 1.5K. From the mass spectrometry, it was found that the ratio, 
C/C
C, differs from statistical one calculated by Poisson distribution for natural graphite. Assuming the recombination of atomic carbons to C
molecules as an initial stage for C formation, the different isotopic ratio of C from Poisson statistics was ascribed to the tunneling recombination between C and C atoms in the bubble state.
Akiyama, Kazuhiko; Sueki, Keisuke*; Tsukada, Kazuaki; Yaita, Tsuyoshi; Miyake, Yoko*; Haba, Hiromitsu*; Asai, Masato; Kodama, Takeshi*; Kikuchi, Koichi*; Otsuki, Tsutomu*; et al.
Journal of Nuclear and Radiochemical Sciences, 3(1), p.151 - 154, 2002/06
The oxidation state of actinide elements encapsulated in fullerenes is studied. HPLC elution behavior of actinide-fullerenes is classified into two groups; the elution behavior of the first group, encapsulating U, Np, and Am, is similar to that of the light lanthanide-fullerenes, such as La, Ce, Pr, and Nd, while the behavior of the second group, encapsulating Th and Pa, is quite different from that of any lanthanide-fullerenes. The chemical species in the main HPLC elution peak of each group were identified as M@C82 and M@C84 (M = metal atom) from the mass of the U and Th fullerenes, respectively. The oxidation states of the U and Th atoms in the fullerenes were deduced to be 3+ and 4+, respectively, from the UV/vis/NIR absorption and XANES spectroscopy.
21, 1997, Tokai-mura, Japan*; ; Sugimoto, Jun
JAERI-Conf 97-011, 829 Pages, 1998/01
no abstracts in English
Akiyama, Mamoru*; Yamano, Norihiro
Nihon Genshiryoku Gakkai-Shi, 35(7), p.630 - 631, 1993/07
no abstracts in English
Yamamura, Osamu; ; Sugiyama, Toshihide; Ikeda, Hisashi ; ; ;
PNC TN8410 91-169, 166 Pages, 1991/05
None
Naganuma, Takashi; Iwatsuki, Teruki; Shimizu, Satoru*; Akiyama, Masaru*; Ishijima, Yoji*
no journal, ,
Microbial communities affect geochemical and hydrogeological processes in deep aquifers, and have been characterized mainly by genetic approaches as well as activity measurements. We have analyzed 16S rDNA assemblages from hydrologically isolated aquifers of porous-but-less-permeable strata in the northernmost part of Japan, and revealed distinctive microbial communities including methanogens and so-far-uncultured species. We have also collected 16S rDNA of the 0.2-micron m-passing-but-0.1-micron m-captured microorganisms from sedimentary and granite rock aquifers in a uranium deposit area of central Japan. In situ activities are characterized and measured by culture-based physiological approaches, which have many limitations and biases though. We have developed a quantification of mRNA for redox-responsive proteins of Fe(III)-reducing bacteria collected from a deep aquifer. This approach is applicable to other aquifer processes such as reduction of nitrate, sulfate, CO, etc.
Kato, Atsushi; Negishi, Kazuo; Sato, Kenichiro*; Akiyama, Yo*; Hara, Hiroyuki*; Iwasaki, Mikinori*; Abe, Ganji*; Tokiyoshi, Takumi*; Okafuji, Takashi*; Umeki, Katsuhiko*; et al.
no journal, ,
Report research and development activities related to steel plate reinforced concrete containment vessel for the JSFR conducted as a part of METI commissioned research.
