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Journal Articles

Adaptation for knowledge management to nuclear research fields

Taruta, Yasuyoshi; Yanagihara, Satoshi*; Iguchi, Yukihiro; Kitamura, Koichi; Tezuka, Masashi; Koda, Yuya

Chishiki Kyoso (Internet), 8, p.IV2_1 - IV2_12, 2018/08

no abstracts in English

Journal Articles

Research concept of decommissioning knowledge management for the Fugen NPP

Taruta, Yasuyoshi; Yanagihara, Satoshi*; Iguchi, Yukihiro; Kitamura, Koichi; Tezuka, Masashi; Koda, Yuya

Proceedings of 26th International Conference on Nuclear Engineering (ICONE-26) (Internet), 6 Pages, 2018/07

The IAEA are developed the discussion for those situations and pointed out the importance of nuclear knowledge management. The nuclear knowledge management is developing a database as nuclear knowledge management. In recent years, the IAEA has also advanced knowledge taxonomies on nuclear accidents. These studies are attempts to appropriately arrange and utilize huge amounts of information. Even in nuclear facilities in Japan, it is pointed out that veteran staff aging and loss of knowledge and skill caused by retirement. Therefore, we created a prototype database system to utilize past knowledge and information for ATR Fugen. Now, there are few cases of past decommissioning that can be utilized. This study of pilot model concept revealed that it is not sufficient to just prepare a past data and information. This is what information other than the construction report requires the decommissioning and what kind of information should be gathered.

Journal Articles

Decommissioning activities in FUGEN

Kitamura, Koichi; Kutsuna, Hideki; Matsushima, Akira; Koda, Yuya; Iwai, Hiroki

Dekomisshoningu Giho, (51), p.2 - 10, 2015/04

Fugen Decommissioning Engineering Center (herein after called as "FUGEN") obtained the approval of the decommissioning program on February 2008. FUGEN has been carrying out decommissioning works based on its decommissioning program since then. Now is in initial stage, the dismantling works was launched in turbine system whose contamination was relatively low level and their various data have been accumulating. And the draining heavy water, tritium decontamination and transferring of heavy water were carried out safely and reasonably. The preparation for the clearance system and the research and development works for the reactor core dismantling have been progressed steadily as well. Meanwhile, FUGEN has affiliation with local industries and universities for collaboration research, and has exchanged the decommissioning information with domestic and overseas organizations continuously.

JAEA Reports

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 3; Progress report on NUMO-JAEA collaborative research in FY2013 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.

JAEA-Research 2014-030, 457 Pages, 2015/03


JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.

Journal Articles

Experimental study for the production cross sections of positron emitters induced from $$^{12}$$C and $$^{16}$$O nuclei by low-energy proton beams

Akagi, Takashi*; Yagi, Masashi*; Yamashita, Tomohiro*; Murakami, Masao*; Yamakawa, Yoshiyuki*; Kitamura, Keiji*; Ogura, Koichi; Kondo, Kiminori; Kawanishi, Shunichi*

Radiation Measurements, 59, p.262 - 269, 2013/12

 Times Cited Count:5 Percentile:46.51(Nuclear Science & Technology)

In proton therapy, positron emitters are induced from $$^{12}$$C and$$^{16}$$O nuclei by protons on the beam path in the patient. Many studies for monitoring positron emitters with beam-induced PET technique have been performed by various groups to verify the proton beam range and the dose in the patient for quality assurance. The aim of this study was to develop a method for measuring the production cross sections of positron emitters using standard equipment for proton therapy. The time-activity curve was then obtained with a high-sensitivity PET scanner to extract the number of positron emitters produced in the target. The production cross sections for four reaction channels: $$^{16}$$O(p,pn)$$^{15}$$O, $$^{16}$$O(p,3p3n)$$^{11}$$C, $$^{16}$$O(p,2p2n)$$^{13}$$N, and $$^{12}$$C(p,pn)$$^{11}$$C were then measured. The cross sections for the $$^{16}$$O(p,pn)$$^{15}$$O reaction channel were consistent with data of previous experiments within the uncertainties, while those of $$^{12}$$C(p,pn)$$^{11}$$C were generally lower than data of previous experiments.

Journal Articles

Full-coherent free electron laser seeded by 13th- and 15th-order harmonics of near-infrared femtosecond laser pulses

Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Yamanouchi, Kaoru*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Togashi, Tadashi*; Fukami, Kenji*; et al.

Journal of Physics B; Atomic, Molecular and Optical Physics, 46(16), p.164006_1 - 164006_6, 2013/08

 Times Cited Count:3 Percentile:81.05(Optics)

By introducing 13th- (61.7 nm) and 15th-order harmonics (53.4 nm) of femtosecond laser pulses at 800 nm into an undulator of SCSS (SPring-8 Compact SASE Source) test accelerator at RIKEN, these harmonic pulses were amplified by a factor of more than 10$$^{2}$$ with a high contrast ratio through the interaction between accelerated electron bunches and the harmonic pulses. From numerical simulations of the amplification processes of high-order harmonic pulses in the undulator, optimum conditions of the electron bunch duration interacting with the high-order harmonic pulses were investigated for generating full-coherent and intense pulses in the extreme ultraviolet wavelength region.

JAEA Reports

Plan for low level radioactive waste management

Kitamura, Koichi; Rindo, Hiroshi; Hasegawa, Makoto; Shimomura, Atsuhiko; Nuclear Cycle Backend Co-ordination Office

JAEA-Technology 2012-008, 57 Pages, 2011/11


The management plan is intended to summarize the process of Low level Radioactive Waste in JAEA from its generation to its treatment and disposal. Reasonable implementation of treatment and disposal for the radioactive waste on ensuring security was taken into account when the plan was made or updated based on the Framework for Nuclear Energy Policy made by Japan Atomic Energy Commission in 2005, the progress situation of laws and regulations, safety guides. Moreover, the issues to be solved during the process of implementation the plan were summarized, they will be studied in the plan, and then, its solutions will be reflected in the research program and project. JAEA will be carried out practical work for treatment and disposal of the radioactive waste based on the plan. Then, the updating will be made flexibly according to technology advance and progress situation of laws and regulations.

Journal Articles

Stability of flower-colour mutants of Delphinium "Momoka" after propagation by tissue culture

Kitamura, Satomi*; Chinone, Shumpei*; Tokuhiro, Koji*; Nakatsubo, Koichi*; Nozawa, Shigeki; Hase, Yoshihiro; Narumi, Issei

JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 64, 2011/01

no abstracts in English

Journal Articles

Extreme ultraviolet free electron laser seeded with high-order harmonic of Ti:sapphore laser

Togashi, Tadashi*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Okino, Tomoya*; Yamanouchi, Kaoru*; et al.

Optics Express (Internet), 19(1), p.317 - 324, 2011/01

 Times Cited Count:74 Percentile:2.85(Optics)

The 13th harmonic of a Ti:sapphire (Ti:S) laser in the plateau region was injected as a seeding source to a 250-MeV free-electron-laser (FEL) amplifier. When the amplification conditions were fulfilled, strong enhancement of the radiation intensity by a factor of 650 was observed. The random and uncontrollable spikes, which appeared in the spectra of the Self-Amplified Spontaneous Emission (SASE) based FEL radiation without the seeding source, were found to be suppressed drastically to form to a narrow-band, single peak profile at 61.2 nm. The properties of the seeded FEL radiation were well reproduced by numerical simulations. We discuss the future precept of the seeded FEL scheme to the shorter wavelength region.

Journal Articles

Relationship between hypocentral distribution and geological structure in the Horonobe area, northern Hokkaido, Japan

Tokiwa, Tetsuya; Asamori, Koichi; Hiraga, Naoto*; Yamada, Osamu; Moriya, Hirokazu*; Hotta, Hikaru*; Kitamura, Itaru*; Yokota, Hideharu

Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.117 - 122, 2010/10

In this paper, we discuss the relationship between the accurate hypocentral distribution and 3-D geological structure in and around the Horonobe area, Japan. We carried out multiplet-clustering analysis by using data of the 421 micro-earthquakes which occurred from 1st September, 2003 to 30th September, 2007. The 3-D geological structure model was mainly constructed from previous seismic reflection profiles and drilling data. As a result of this analysis, although there are some differences in depth between them, the hypocenters are distributed in NNW-SSE direction and become deeper from the west toward the east. The distributed pattern of the hypocenters is similar to the one of the geological structure. These results indicate that the hypocentral distribution may represent existence of active zone related to the geological structure, and provide effective information which can contribute to establishing methods for estimating the future evolution of the geological environment.

Journal Articles

Decommissioning program for ATR-FUGEN nuclear power station

Sano, Kazuya; Kitamura, Koichi; Tezuka, Masashi; Mizui, Hiroyuki; Kiyota, Shiko; Morishita, Yoshitsugu

Proceedings of 16th Pacific Basin Nuclear Conference (PBNC-16) (CD-ROM), 6 Pages, 2008/10

The operation of Advanced Thermal Reactor Fugen was terminated on Mar. 29th, 2003. After the operation, the preparative works and R&D have been conducted strenuously for the planning of the rational and safe decommissioning. The decommissioning program for Fugen was planed, based on the results of above works and R&D, and was applied to the government as a first case under the revised nuclear reactor regulation law. As a result, the program was approved on Feb. 12th, 2008. In this paper, the decommissioning program for Fugen was outlined, which are the dismantling process consists of four periods; (1) Spent fuel transportation, (2) Periphery facilities dismantlement, (3) Reactor dismantlement and (4) Building demolition, the amount of radioactive waste, the safety assessment etc.

JAEA Reports

Study on evaluation method of potential impact of natural phenomena on a HLW disposal system

Kawamura, Makoto; Oi, Takao; Niizato, Tadafumi; Yasue, Kenichi; Tokiwa, Tetsuya; Niwa, Masakazu; Shimada, Koji; Kurosawa, Hideki; Asamori, Koichi; Kawachi, Susumu; et al.

JAEA-Research 2008-018, 47 Pages, 2008/03


In this report, we sophisticated the framework as a part of the total system performance assessment for two purposes: the first one is quantification of relationship of characteristic of natural phenomena between geological environmental conditions (THMCG), and the other one is quantification of relationship of THMCG condition between parameters of performance assessment. On the other hand, we applied the sophisticated framework to all natural phenomena. As a result, to apply the sophisticated framework, we could show that information integration could carry out efficiently. Moreover, we have checked that the framework was applicable to all phenomena. Furthermore, we could show that suitable scenarios might be chosen by information integration.

Journal Articles

Evaluation of radioactive inventory for Fugen's decommissioning

Kitamura, Koichi; Hayashi, Hirokazu; Morishita, Yoshitsugu; Tanji, Kazuhiro*

Hoshasen, 34(1), p.53 - 63, 2008/01

It is very important to evaluate radioactive inventory and an amount of radioactive waste accurately for both the planning and the safety assessment on Fugen's decommissioning. Fugen had carried out various radioactive inventory investigations, activation evaluations by materials sampling, neutron measurements, contamination evaluation by investigation of radiation control records, etc. since operation period because Fugen uses heavy water as moderator and its core structure is different from that of LWR. And then, radioactive inventory was evaluated using those investigation data. Moreover, an amount of radioactive waste was estimated by the classification for the radioactive waste disposal based on the evaluated radioactive inventory results. This paper is intended to introduce the evaluation methods and results of the radioactive inventory and estimation of an amount of radioactive waste for Fugen.

Journal Articles

Preliminary numerical investigation of turbulence behavior in a spallation target

Takase, Kazuyuki; Kitamura, Tatsuaki*; Kume, Etsuo; Ichimiya, Koichi*; Komada, Ichiro*

Nippon Kikai Gakkai Kanto Shibu Yamanashi Koenkai (2003) Koen Rombunshu, No.030-4, p.77 - 78, 2003/00

no abstracts in English

Journal Articles

Development and Experience of Tritium Control in Heavy Water Reactor "FUGEN"

Kitamura, Koichi; Kitabata, Takuya; Matsushima, Akira

Purazuma, Kaku Yugo Gakkai-Shi, 78(12), p.1313 - 1318, 2002/12


Journal Articles

In situ EXAFS study on GeS$$_{2}$$ glass under high-pressure

Miyauchi, Koichi*; Qiu, J.*; Shojiya, Masanori*; Kawamoto, Yoji*; Kitamura, Naoyuki*; Fukumi, Kohei*; Katayama, Yoshinori; Nishihata, Yasuo

Solid State Communications, 124(5-6), p.189 - 193, 2002/10

 Times Cited Count:5 Percentile:66.36

A GeS$$_{2}$$ glass was compressed up to 8 GPa at room temperature, heated up to 270 $$^{circ}$$C under 8 GPa and then decompressed to ambient pressure at room temperature, using a large volume high-pressure apparatus. The local structural-changes around Ge were examined by means of EXAFS method. The Ge-S bond length became monotonously short with increasing applied-pressure up to 8 GPa at room temperature. When the specimen was heated to 270 $$^{circ}$$C under 8 GPa, however, the vond length became slightly long. The elongated bond lengthe was almost kept even after the temperature was descended to room tempertature. In decompression process, the bond length became gradually long with releasing applied-pressure down to 2 GPa, following a change in compression process. Below 2 GPa, however, the Ge-S bond length was largely elongated, being lnger than the initial one. No significant change of coordination number was found in the compression and decompression processes up to 8 GPa. This change canbe explained by a combined effect of elastic and inelastic structural-changes.

Journal Articles

Dynamic analysis of the tokamak support system in ITER

*; Kitamura, Kazunori*; *; Koizumi, Koichi; Tada, Eisuke; Tsunematsu, Toshihide

Fusion Engineering and Design, 41, p.421 - 429, 1998/00

 Times Cited Count:2 Percentile:73.06

no abstracts in English

JAEA Reports

FBR fuel reprocessing pulsed colum test; Evaluation of operation parameter for strip in pulsed columm

; *; *; Nemoto, Shinichi; Kitamura, Koichiro

PNC-TN8410 87-084, 144 Pages, 1987/06


no abstracts in English

JAEA Reports

FBR fuel reprocessing pulsed column equipment, II test; A change for the worse of extraction column dispersion state and its cause

*; ; *; Tanaka, Mutsuo; Nemoto, Shinichi; Kitamura, Koichiro

PNC-TN8410 87-082, 92 Pages, 1987/04


no abstracts in English

JAEA Reports

FBR fuel reprocessing plused column equipment test; Operating characteristics of pulsed ploto columms on the condition of the qqueous continous phase

*; ; *; *; *; Kitamura, Koichiro; *; *; *; Ueno, Kazuhiro

PNC-TN8410 87-081, 98 Pages, 1986/12


no abstracts in English

55 (Records 1-20 displayed on this page)