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Uchibori, Akihiro; Doda, Norihiro; Aoyagi, Mitsuhiro; Sonehara, Masateru; Sogabe, Joji; Okano, Yasushi; Takata, Takashi*; Tanaka, Masaaki; Enuma, Yasuhiro; Wakai, Takashi; et al.
Nuclear Engineering and Design, 413, p.112492_1 - 112492_10, 2023/11
Times Cited Count：1 Percentile：68.31(Nuclear Science & Technology)The ARKAIDA has been developed to realize automatic optimization of plant design from safety evaluation for the advanced reactors represented by a sodium-cooled fast reactor. ARKADIA-Design offers functions to support design optimization both in normal operating conditions and design basis events. The multi-level simulation approach by the coupled analysis such as neutronics, core deformation, core thermal hydraulics was developed as one of the main technologies. On the other hand, ARKAIDA-Safety aims for safety evaluation considering severe accidents. As a key technology, the numerical methods for in- and ex-vessel coupled phenomena during severe accidents in sodium-cooled fast reactors were tested through a hypothetical severe accident event. Improvement of the ex-vessel model and development of the AI technology to find best design solution have been started.
Uchibori, Akihiro; Sogabe, Joji; Okano, Yasushi; Takata, Takashi*; Doda, Norihiro; Tanaka, Masaaki; Enuma, Yasuhiro; Wakai, Takashi; Asayama, Tai; Ohshima, Hiroyuki
Proceedings of Technical Meeting on State-of-the-art Thermal Hydraulics of Fast Reactors (Internet), 10 Pages, 2022/09
The ARKAIDA has been developed to realize automatic optimization of plant design from safety evaluation for the advanced reactors represented by a sodium-cooled fast reactor. ARKADIA-Design offers functions to support design optimization both in normal operating conditions and design basis events. The multi-level simulation approach by the coupled analysis such as neutronics, core deformation, core thermal hydraulics was developed as one of the main technologies of the ARKADIA-Design. On the other hand, ARKAIDA-Safety aims for safety evaluation considering severe accidents. As a key technology, the numerical methods for in- and ex-vessel coupled phenomena during severe accidents in sodium-cooled fast reactors were tested through a hypothetical severe accident event.
Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.
High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02
As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950
C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.
Shiino, Keisuke*; Otomo, Toshiya; Yamada, Takeshi*; Arima, Hiroshi*; Hiroi, Kosuke; Takata, Shinichi; Miyake, Jumpei*; Miyatake, Kenji*
ACS Applied Polymer Materials (Internet), 2(12), p.5558 - 5565, 2020/11
Times Cited Count：23 Percentile：77.93(Materials Science, Multidisciplinary)Takada, Kenta*; Sato, Tatsuhiko; Kumada, Hiroaki*; Koketsu, Junichi*; Takei, Hideyuki*; Sakurai, Hideyuki*; Sakae, Takeji*
Journal of Radiation Research, 59(1), p.91 - 99, 2018/01
Times Cited Count：35 Percentile：88.37(Biology)Evaluation of the relative biological effectiveness (RBE)-weighted dose is indispensable in the treatment planning of proton and carbon ion therapies. In this study, we validate the RBE-weighted dose calculated by microdosimetric kinetic model (MKM) in tandem with the Monte Carlo particle transport code PHITS for proton therapy using the full simulation geometry for the beam line of the Proton Medical Research Center at the University of Tsukuba. The physical dose and RBE-weighted dose on the central axis for a 155 MeV monoenergetic and spread-out Bragg peak beam of 60 mm width are evaluated by the method. The calculated results generally agree with the corresponding experimental data very well, though overestimations by approximately 3.2% and 15% at the maximum are observed for the physical and RBE-weighted doses, respectively. This research completes the computational microdosimetric approach based on a combination of PHITS and MKM for all types of radiotherapy that require RBE evaluations.
Kaji, Yoshiyuki; Kondo, Keietsu; Aoyagi, Yoshiteru; Kato, Yoshiaki; Taguchi, Taketoshi; Takada, Fumiki; Nakano, Junichi; Ugachi, Hirokazu; Tsukada, Takashi; Takakura, Kenichi*; et al.
Proceedings of 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors (CD-ROM), p.1203 - 1216, 2011/08
In order to investigate the effect of neutron dose rate on tensile property and irradiation assisted stress corrosion cracking (IASCC) growth behavior, the crack growth rate (CGR) test, tensile test and microstructure observation have been conducted with type 304 stainless steel specimens. The specimens were irradiated in high temperature water simulating the temperature of boiling water reactor (BWR) up to about 1dpa with two different dose rates at the Japan Materials Testing Reactor (JMTR). The radiation hardening increased with the dose rate, but there was little effect on CGR. Increase of the yield strength of specimens irradiated with the low dose rate condition was caused by the increase of number density of frank loops. Little difference of radiation-induced segregation at grain boundaries was observed in specimens irradiated by different dose rates. Furthermore, there was little effect on local plastic deformation behavior near crack tip in the crystal plasticity simulation.
Kanamori, Masashi; Suto, Toshiyuki; Tanaka, Kenichi*; Takada, Jun*
JAEA-Technology 2011-004, 12 Pages, 2011/03
JAEA-Technology-2011-004.pdf:0.97MB
In the previous report "A Study on Dose Control for JCO Criticality Accident Termination" (JAEA-Technology 2009-043), we discussed how to control the dose received during the termination work of the criticality accident. In this paper, we focused on the difference of the way in which dose rate attenuates between within 100 m from the source point and beyond 100 m and discussed the validity of using log-log plotting/semi-log plotting of dose rate - distance relation in order to extrapolate the dose rate at work place near the criticality accident point. In addition, we studied on the effect of the number of dose rate measurement data to be used for extrapolation. We recommend that about 10 mSv which is a half of 20 mSv annual dose limit should be used as worker's dose control target for the high neutron dose field work to ensure enough safety margin considering the following three points; (1) annual dose limit for workers, (2) dose received before, (3) measurement error.
Kanamori, Masashi; Suto, Toshiyuki; Tanaka, Kenichi*; Takada, Jun*
JAEA-Technology 2010-042, 11 Pages, 2011/01
JAEA-Technology-2010-042.pdf:0.94MB
JAEA-Technology 2009-043 "A Study on dose control for JCO criticality accident termination", the dose we discuss how to manage termination of the criticality accident at work or (we refer as previously report) As a result, based on the measurements from around 40 m to 100 m, we made a re-evaluation of the dose. Reevaluated doses match with the degree of accuracy 60% to 80% compared with the respective individual dose. In this paper, we validate by these doses by using log-log plots and semi-log plots for the distance from the source approximately 100 m and further attenuation. As a result, if the field is under high doses of neutrons, dose constraint assessment should consider some points, by using 10 mSv, half of the annual limit 20 mSv, as dose reference, the work performed could safely be managed. And summaries the valid range of log-log plots for intense neutron dose estimation.
Kanamori, Masashi; Suto, Toshiyuki; Tanaka, Kenichi*; Takada, Jun*
JAEA-Technology 2010-025, 11 Pages, 2010/08
JAEA-Technology-2010-025.pdf:1.55MB
Verification of dose control method for Tokaimura JCO criticality accident was performed. Personal dose estimation for Tokaimura criticality accident termination was performed based on measurements of neutron and 
ray doses taken before the work commenced, but the personal dose for the workers as a result of the termination work was found to be approximately 50 times higher than the previous estimation. For this report, we reevaluated doses based on the results of close range measurements from 40 meters to 100 meters, and the results were found to match personal doses with an accuracy of between 60-80%.
Kanamori, Masashi; Tanaka, Kenichi*; Takada, Jun*
JAEA-Technology 2009-043, 32 Pages, 2009/08
JAEA-Technology-2009-043.pdf:1.6MBJAEA-Technology-2009-043(errata).pdf:0.04MB
At the time of the JCO criticality accident termination, dose estimation from the preliminary neutron and measurement, it was about around 50 times lower. The estimation might effect from the surrounding buildings. In this report, re-estimation based on the measurements at short distances from the criticality, around 40 m to 100 m, which are 20 mSv/h to 3 mSv/h was done. The re-estimated doses are correspond with the measured doses within 60-80% error. Dose estimation under the high radiation field, around 100 mSv, in order to decide the dose limit for the preliminary measurement, annual dose limit, other exposure possibility and measurement error have to be considered. From this point of view, the dose limit for the preliminary measurement itself considered to be 10 mSv, which is half of annual 20 mSv limit.
Uchimura, Yosuke*; Saiki, Yumi*; Takata, Kinuko*; Hase, Yoshihiro; Yoshihara, Ryohei; Narumi, Issei
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 63, 2008/11
no abstracts in English
L.)Saiki, Yumi*; Takata, Kinuko*; Uchimura, Yosuke*; Hirashima, Keita*; Nakahara, Takao*; Hase, Yoshihiro; Yokota, Yuichiro; Tanaka, Atsushi
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 70, 2008/03
no abstracts in English
Uchimura, Yosuke*; Takata, Kinuko*; Saiki, Yumi*; Hirashima, Keita*; Nakahara, Takao*; Hase, Yoshihiro; Yokota, Yuichiro; Tanaka, Atsushi
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 80, 2007/02
no abstracts in English
Takada, Tomoyuki; Miyoshi, Yoshinori; Katakura, Junichi
JAERI-Tech 2003-036, 80 Pages, 2003/03
JAERI-Tech-2003-036.pdf:3.67MB
In order to perform accuracy evaluation of the critical calculation by the combination of multi-group constant library MGCL and 3-dimensional Monte Carlo code KENO-IV among critical safety evaluation code system JACS, benchmark calculation was carried out from 1980 in 1982. Some cases where the neutron multiplication factor calculated in the heterogeneous system in it was less than 0.95 were seen. In this report, it re-calculated by considering the cause about the heterogeneous system of the U+Pu nitric acid solution systems containing the neutron poison shown in JAERI-M 9859. The present study has shown that the keff value less than 0.95 given in JAERI-M 9859 is caused by the fact that the water reflector below a cylindrical container was not taken into consideration in the KENO-IV calculation model. By taking into the water reflector, the KENO-IV calculation gives a keff value greater than 0.95 and a good agreement with the experiment.
Saito, Masahiro*; Okada, Noriko*; Nishibori, Eiji*; Takagiwa, Hiroyuki*; Yokoo, Tetsuya*; Nishi, Masakazu*; Kakurai, Kazuhisa; Kunii, Satoru*; Takata, Masaki*; Sakata, Makoto*; et al.
Journal of the Physical Society of Japan, 71(10), p.2369 - 2372, 2002/10
Times Cited Count：14 Percentile：62.19(Physics, Multidisciplinary)no abstracts in English
Nishitani, Takeo; Iguchi, Tetsuo*; *; Kaneko, Junichi; Kasai, Satoshi; Matoba, Toru
Proc., Workshop on Diagnostics for Experimental Thermonuclear Fusion Reactors, 0, p.425 - 434, 1996/00
no abstracts in English
Takata, Hyoe*; Kuma, Kenshi*; Isoda, Yutaka*; Nishioka, Jun*; Otosaka, Shigeyoshi; Chikira, Mitsuru*; Takagi, Shogo*; Kamei, Yoshihiko*; Sakaoka, Keiichiro*
no journal, ,
The authors discussed on the difference of behavior of iron between two basins (the Yamato Basin and Japan Basin) in the Japan Sea by measurements of iron (dissolved and labile dissolved phases) and nutrients in seawater. Concentration of labile dissolved iron in the surface water was about 1.0 nM and did not show difference between the basins. On the other hand, concentration of labile dissolved iron in the Japan Basin increased to 4.5 nM at 1-2 km depth and decreased to 4 nM in the bottom layer. In the Yamato Basin, concentration of labile dissolved iron in deep water increased uniformly and was about 6 nM at the bottom layer. The difference in distribution of iron in seawater indicates that the transport processes of biogenic elements in the deep layers are different between the basins of the Japan Sea.
Uchimura, Yosuke*; Takata, Kinuko*; Saiki, Yumi*; Hirashima, Keita*; Nakahara, Takao*; Hase, Yoshihiro; Yokota, Yuichiro; Tanaka, Atsushi
no journal, ,
no abstracts in English
Uchimura, Yosuke*; Saiki, Yumi*; Takata, Kinuko*; Hirashima, Keita*; Nakahara, Takao*; Hase, Yoshihiro; Yoshihara, Ryohei; Narumi, Issei
no journal, ,
no abstracts in English
