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Tobita, Yoshiharu; Kamiyama, Kenji; Tagami, Hirotaka; Matsuba, Kenichi; Suzuki, Toru; Isozaki, Mikio; Yamano, Hidemasa; Morita, Koji*; Guo, L.*; Zhang, B.*
Journal of Nuclear Science and Technology, 53(5), p.698 - 706, 2016/05
Times Cited Count：23 Percentile：89.8(Nuclear Science & Technology)The in-vessel retention (IVR) of core disruptive accident (CDA) is of prime importance in enhancing safety characteristics of sodium-cooled fast reactors (SFRs). In the CDA of SFRs, molten core material relocates to the lower plenum of reactor vessel and may impose significant thermal load on the structures, resulting in the melt through of the reactor vessel. In order to enable the assessment of this relocation process and prove that IVR of core material is the most probable consequence of the CDA in SFRs, a research program to develop the evaluation methodology for the material relocation behavior in the CDA of SFRs has been conducted. This program consists of three developmental studies, namely the development of the analysis method of molten material discharge from the core region, the development of evaluation methodology of molten material penetration into sodium pool, and the development of the simulation tool of debris bed behavior.
Abe, Shinichiro; Sato, Tatsuhiko; Matsuba, Hirotaka*; Watanabe, Yukinobu*
Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.45 - 48, 2015/11
Secondary cosmic-rays have been recognized as a cause of soft errors for microelectronics in terrestrial environment. Recently, the contribution of terrestrial muons to soft errors is concerned for advanced microelectronics because it becomes small and sensitive to radiation. Muons generate energetic secondary through photonuclear interaction and negative muon capture. In the present work, we investigate the effect of these interactions on terrestrial muon-induced soft errors. The analysis of soft error rate (SER) in the 25-nm design rule NMOSFET is performed based on the multiple sensitive volume (MSV) model using PHITS. It is clarified that the terrestrial muon-induced SER is a few or less of neutron-induced SER and it is mainly caused though negative muon capture while the effect of muon photonuclear interaction is small. It is also found that direct ionization only affects soft errors with extremely low critical charge.
Suzuki, Toru; Tobita, Yoshiharu; Kawada, Kenichi; Tagami, Hirotaka; Sogabe, Joji; Matsuba, Kenichi; Ito, Kei; Ohshima, Hiroyuki
Nuclear Engineering and Technology, 47(3), p.240 - 252, 2015/04
Times Cited Count：27 Percentile：91.4(Nuclear Science & Technology)Ikeda, Makoto; Munakata, Masahiro; Sakai, Ryutaro; Fuchiwaki, Hirotaka; Kimura, Hideo; Matsuba, Hisashi*
Nihon Chikasui Gakkai 2010-Nen Shuki Koenkai Koen Yoshi, p.282 - 287, 2010/11
no abstracts in English
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Matsuba, Kenichi; Ito, Chikara; Kawahara, Hirotaka; Aoyama, Takafumi
Journal of Power and Energy Systems (Internet), 2(2), p.545 - 556, 2008/00
Significant thermal stresses are loaded onto the structures of sodium-cooled fast reactor (SFR) due to high temperature and large temperature gradients associated with employing sodium coolant with its high thermal conductivity and low heat capacity. Therefore, it is important to monitor the temperature variation, related stress and displacement, and vibration in the cooling system piping and components in order to assure structural integrity while the reactor plant is in-service. SFR structural integrity monitoring can be enhanced by an optical fiber sensor, which is capable of continuous or dispersed distribution measurements of various properties such as radiation dose, temperature, strain, displacement and acceleration. In the experimental fast reactor Joyo, displacement and vibration measurements of the primary cooling system have been carried out using Fiber Bragg Grating (FBG) sensors to evaluate the durability and measurement accuracy of FBG sensors in a high 
-ray environment. The data were successfully obtained with no significant signal loss up to an accumulated -ray dose of approximately 4
10
Gy corresponding to 120 EFPDs operation. Measured displacement of the piping support was nearly equal to the calculated thermal displacement. Measured vibration power spectra of the piping support were similar to those measured with a reference acceleration sensor. The measured results indicate that the FBG sensor is suitable for monitoring the displacement and vibration aspects of fast reactor cooling system integrity in a high -ray environment.
Matsuba, Kenichi; Ito, Chikara; Kawahara, Hirotaka; Aoyama, Takafumi
Dai-12-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.13 - 14, 2007/06
no abstracts in English
Matsuba, Kenichi; Ito, Chikara; Kawahara, Hirotaka; Aoyama, Takafumi
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 8 Pages, 2007/04
Significant thermal stresses are loaded on the structures of sodium-cooled fast reactor (SFR) due to high temperature and large temperature gradients associated with employing sodium coolant. Therefore, it is important to monitor the temperature variation and related stress on the cooling system piping in order to assure structural integrity. Structural integrity monitoring can be enhanced by an optical fiber sensor, which is capable of continuous or dispersed distribution measurements of various physical properties such as radiation dose, temperature, strain, displacement and acceleration. In the experimental fast reactor Joyo, displacement and vibration measurements of the primary cooling system have been carried out using Fiber Bragg Grating (FBG) sensors to evaluate the durability and measurement accuracy of FBG sensors in a high ray environment. The data were successfully obtained with no significant signal loss up to an accumulated ray dose of approximately 410Gy corresponding to 120EFPDs operation. Measured displacement of the piping support was nearly equal to the calculated thermal displacement. Measured vibration power spectra of the piping support were similar to those measured with a reference acceleration sensor. The measured results indicate that the FBG sensor is applicable for monitoring the displacement and vibration of fast reactor cooling system integrity in a high ray environment.
Matsuba, Kenichi; Kawahara, Hirotaka; Aoyama, Takafumi
JAEA-Conf 2006-003, p.24 - 37, 2006/05
The experimental fast reactor JOYO at O-arai Engineering Center of Japan Nuclear Cycle Development Institute is the first liquid metal cooled fast reactor in Japan. This paper describes the plant outline, experiences on the fast reactor technology and test results accumulated through twenty eight years successful operation of JOYO.
Matsuba, Kenichi; Kawahara, Hirotaka; Ito, Chikara; Yoshida, Akihiro; Nakai, Satoru
UTNL-R-0453, p.12_1 - 12_10, 2006/03
no abstracts in English
Matsuba, Kenichi; Kawahara, Hirotaka; Aoyama, Takafumi
no journal, ,
In JOYO, strain and vibration multi-point measurements of the primary cooling system piping have been carried out using a Fiber Bragg Graing (FBG) sensor. Through these measurements, applicability of a FBG sensor in a low-radiation environment was confirmed.
Matsuba, Kenichi; Ito, Chikara; Kawahara, Hirotaka
no journal, ,
no abstracts in English
Matsuba, Kenichi; Ito, Chikara; Kawahara, Hirotaka
no journal, ,
no abstracts in English
Fuchiwaki, Hirotaka; Matsuba, Hisashi; Munakata, Masahiro
no journal, ,
This study was conducted to develop methodologies of regional scale to be assessed for long-term groundwater flow systems. Through the GIS techniques, this study is being advanced. As the application case, at crystalline rock distribution area 3 examples and sedimentary rock distribution area 1 example, this study was executed respectively. In regard to latter 1 example, concerning the analytical object range when future topographical sea level change is considered it examined. As a result, concerning the analytical range for the underground water flow analysis presently for topography, what can set the analytical territory in the rational range making use of the GIS analytical result was found. In addition, it was found that supposition of the time scale is important concerning the analytical range which considers future topographical change and sea level change.
Kimura, Hideo; Munakata, Masahiro; Hanatani, Ikuo; Sakai, Ryutaro; Fuchiwaki, Hirotaka; Matsuba, Hisashi
no journal, ,
no abstracts in English
Tobita, Yoshiharu; Kamiyama, Kenji; Suzuki, Toru; Matsuba, Kenichi; Tagami, Hirotaka; Yamano, Hidemasa; Morita, Koji*; Guo, L.*; Zhang, B.*
no journal, ,
The development program to develop the assessment methodology to analyze the fuel escape behavior and self-leveling behavior, which can be applicable to the design study and safety evaluation, and the progress of the development of analysis methodology of fuel escape behavior from core are presented.
Matsuba, Hirotaka*; Watanabe, Yukinobu*; Abe, Shinichiro
no journal, ,
Stored data on semiconductor device is flipped by incident radiation (so-called Single Event Upset, SEU), and temporal malfunction (so-called soft error) is caused on microelectronics. Recently, the effect of terrestrial muons to soft error is suggested because devices become small and sensitive to radiation. Soft errors can be caused not only by muon direct ionization but also by secondary ions generated by negative muon capture reaction. The analysis of soft error rate (SER) in the 65, 45, 32 and 25-nm technology NMOSFET is performed based on the single sensitive volume model using PHITS. It is clarified that the terrestrial muon-induced SER shows a decreasing trend which is similarly to terrestrial neutron-induced SER. From the detailed analysis for 25-nm technology NMOSFET, it is clarified that muon direct ionization and secondary ions generated by negative muon capture affect on soft error.
Son, E.*; Sheikh, Md. A. R.*; Matsumoto, Tatsuya*; Morita, Koji*; Matsuba, Kenichi; Toyooka, Junichi; Tagami, Hirotaka; Kamiyama, Kenji
no journal, ,
To clarify the sedimentation behavior of fuel debris particles formed by molten fuel-coolant interaction in core disruptive accidents of sodium-cooled fast reactors, experiments pouring mixed particles simulating fuel debris into a water pool were conducted. In the experiments, effects of experimental parameters on the characteristics of particle bed formation were investigated. Based on the results of the experiments, an empirical correlation to predict quantitatively the center height of the bed composed of mixed particles with different sizes was developed. Bed height predicted using the correlation agreed well with the experimental results. Applicability of the developed correlation to the prediction of the center height of the bed composed of mixed particles with different sizes was confirmed.
Wen, J.*; Kamada, Yuto*; Yokoyama, Kosei*; Matsumoto, Tatsuya*; Liu, W.*; Morita, Koji*; Imaizumi, Yuya; Tagami, Hirotaka; Matsuba, Kenichi; Kamiyama, Kenji
no journal, ,
