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Tamakuma, Yuki*; Yamada, Ryohei; Suzuki, Takahito*; Kuroki, Tomohiro*; Saga, Rikiya*; Mizuno, Hiroyuki*; Sasaki, Hiroyuki*; Iwaoka, Kazuki*; Hosoda, Masahiro*; Tokonami, Shinji*
Radiation Protection Dosimetry, 184(3-4), p.307 - 310, 2019/10
Times Cited Count：1 Percentile：11.15(Environmental Sciences)After the Fukushima Daiichi Nuclear Power Plant accident, the radiation dose for first responders was not evaluated accurately due to lack of the monitoring data. It has been important to evaluate a radiation dose for workers in emergency response at a nuclear accident. In this study, a new device which can evaluate both of external and internal exposure doses was developed and the performance of various environmental radiation monitors including commercially available monitors were tested and compared from the viewpoint of an environmental monitoring at emergency situation. Background counts of the monitors and the ambient dose equivalent rate were measured in Fukushima Prefecture. The detection limit for beta particles was evaluated by the method of ISO11929. The sensitivity for gamma-rays of the dust monitor using a ZnS(Ag) and a plastic scintillator was high, but that of the external exposure monitor using a silicon photodiode with CsI(Tl) crystal was relatively low. The detection limit ranged 190-280 Bq m
at 100 
Sv h
, exceeding the detection limit of 100 Bq m in the minimum requirement by the National Regulation Authority in Japan. Use of the shielding with lead is necessary to achieve the minimum requirement. These results indicate that the dust monitor using a ZnS(Ag) scintillator and a plastic scintillator is suitable for the external exposure monitor and the developed internal exposure monitor is for the internal exposure monitor at emergency situation among the evaluated monitors. In the future study, the counting efficiency, the relative uncertainty and the performance of the detection for alpha particles will be evaluated, and it will be considered which type of a monitor is suitable after taking the portability into account.
Tamakuma, Yuki*; Yamada, Ryohei; Iwaoka, Kazuki*; Hosoda, Masahiro*; Kuroki, Tomohiro*; Mizuno, Hiroyuki*; Yamada, Koji*; Furukawa, Masahide*; Tokonami, Shinji*
Perspectives in Science (Internet), 12, p.100414_1 - 100414_4, 2019/09
In this study, a portable radioactive plume monitor using a silicon photodiode was developed for the detection of a radioactive plume (e.g. 
I, 
Cs and 
Cs) in an emergency situation. It was found that the background count rate was proportional to ambient dose equivalent rate and the detection limit for the monitor at 20 Sv h as an ambient dose equivalent rate was evaluated to be 187 Bq m using the ISO11929 method. These results suggest that the detection limit for the system can be decreased effectively by lead shielding with optimized thickness.
Ishida, Shinya; Mizuno, Masahiro*
JAEA-Research 2015-002, 47 Pages, 2015/06
JAEA-Research-2015-002.pdf:7.22MB
An advanced safety analysis computer code, SIMMER-III and SIMMER-IV, has been developed to investigate the complex phenomena under the core disruptive accidents in LMFRs. Fuel slumping experiments performed in the Fast Critical Assembly (FCA) VIII-2 facility were analyzed by SIMMER-III (two dimensions) and SIMMER-IV (three dimensions) in order to validate the neutronics model of the code for the disrupted core analysis. The results of the SIMMER-III and SIMMER-IV analysis (70-group constants from the unified cross-section set ADJ2000R, multi-group transport approximation for the anisotropic scattering, S8 approximation for the discrete-ordinate order) indicated that the SIMMER-III and SIMMER-IV simulated the FCA VIII-2 experiments with sufficient precision. In addition, the parameter surveys showed that the simulation of the FCA VIII-2 experiments with sufficient precision can be performed with the 18-group constants and S4 approximation for the discrete-ordinate order.
Uwaba, Tomoyuki; Mizuno, Tomoyasu; Nemoto, Junichi*; Ishitani, Ikuo*; Ito, Masahiro*
Nuclear Engineering and Design, 280, p.27 - 36, 2014/12
Times Cited Count：11 Percentile：64.59(Nuclear Science & Technology)A deterministic computer code CEDAR has been developed to analyze irradiation behaviors of a mixed-oxide fuel pellet pin in a FBR. The FEM was incorporated into the mechanical calculation part of the code for properly analyzing stress-strain status in the fuel pellet and cladding, and mechanical interaction between the fuel pellet and cladding. The code features mechanistic analyses of irradiation behaviors of a fuel pin by integrating a lot of models to analyze major irradiation phenomena, thus expressing actual fuel pin irradiation behaviors. Analysis capabilities of the code were validated by calculations of fuel pellet temperatures, fractional fission gas releases of fuel pins and fuel pin cladding diametral strain profiles. The mechanisms of the fuel pin irradiation behaviors such as redistribution of Americium, PCMI and JOG formation were interpreted from the code analyses for the actual irradiation test fuel pins.
Uwaba, Tomoyuki; Ito, Masahiro*; Mizuno, Tomoyasu; Katsuyama, Kozo; Makenas, B. J.*; Wootan, D. W.*; Carmack, J.*
Journal of Nuclear Materials, 412(3), p.294 - 300, 2011/05
Times Cited Count：11 Percentile：66.82(Materials Science, Multidisciplinary)The ACO-3 irradiation test, which attained extremely high burnups of about 232 GWd/t and resisted a high neutron fluence of about 39
10
n/m
as one of the lead tests of the Core Demonstration Experiment in the Fast Flux Test Facility, demonstrated that the fuel pin cladding made of ferritic/martensitic HT-9 alloy had superior void swelling resistance. The measured diameter profiles of the irradiated ACO-3 fuel pins showed axially extensive incremental strain in the MOX fuel column region and localized incremental strain near the interfaces between the MOX fuel and upper blanket columns. These incremental strains were as low as 1.5% despite the extremely high level of the fast neutron fluence. Evaluation of the pin diametral strain indicated that the incremental strain in the MOX fuel column region was substantially due to cladding void swelling and irradiation creep caused by internal fission gas pressure, while the localized strain near the MOX fuel/upper blanket interface was likely the result of the pellet/cladding mechanical interaction (PCMI) caused by cesium/fuel reactions. The evaluation also suggested that the PCMI was effectively mitigated by a large gap size between the cladding and blanket column.
Uwaba, Tomoyuki; Sogame, Motomu; Ito, Masahiro*; Mizuno, Tomoyasu; Donomae, Takako; Katsuyama, Kozo
Journal of Nuclear Science and Technology, 47(8), p.712 - 720, 2010/08
Times Cited Count：6 Percentile：40.28(Nuclear Science & Technology)In determining lifetime criteria of fast reactor fuel pins, creep damage due to fission gas pressure on mixed-oxide fuel pins with austenitic stainless steel cladding successfully irradiated to high burnups (120 GWd/t or higher pin averaged burnup) was evaluated. The degree of creep damage of these fuel pins was expressed as cumulative damage fractions (CDFs), defined so that cladding breaching occurs when the CDF exceeds 1.0. The obtained CDFs for typical high temperature fuel pins were on the order of 10
-10
at the end of irradiation, indicating that these fuel pins had large safety margins against breaching due to creep damage. In order to investigate the factors that govern the lifetime of fuel pins, pin diametral increase as well as CDF were predicted in cases of extended burnups from 120 GWd/t onward, and then were compared with tentatively determined limit values. The predicted pin diametral increase reached its limit value earlier than the CDF because of a significant increase in the cladding void swelling, suggesting that lifetimes of fuel pins with austenitic stainless steel cladding are practically governed by the diametral increase rather than by the creep damage.
Tsuruta, Tadahiko; Uchida, Masahiro; Hama, Katsuhiro; Matsui, Hiroya; Takeuchi, Shinji; Amano, Kenji; Takeuchi, Ryuji; Saegusa, Hiromitsu; Matsuoka, Toshiyuki; Mizuno, Takashi
Proceedings of 12th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM '09/DECOM '09) (CD-ROM), 8 Pages, 2009/10
Takeuchi, Shinji; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Amano, Kenji; Matsuoka, Toshiyuki; Hayano, Akira; Takeuchi, Ryuji; Saegusa, Hiromitsu; Oyama, Takuya; et al.
JAEA-Review 2009-017, 29 Pages, 2009/08
JAEA-Review-2009-017.pdf:3.69MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named the Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at the MIU project is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following 2009 fiscal year plan based on the MIU Master Plan updated in 2002, (1) Investigation Plan, (2) Construction Plan, (3) Research Collaboration Plan, etc.
Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Mizuno, Takashi; et al.
JAEA-Review 2009-002, 88 Pages, 2009/03
JAEA-Review-2009-002-1.pdf:29.31MBJAEA-Review-2009-002-2.pdf:35.38MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase I), Construction Phase (Phase II) and Operation Phase (Phase III). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2007 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site and the Shobasama Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.
Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Yoshida, Haruo*; et al.
JAEA-Review 2009-001, 110 Pages, 2009/03
JAEA-Review-2009-001.pdf:49.84MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2006 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.
Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Yoshida, Haruo*; et al.
JAEA-Review 2008-073, 99 Pages, 2009/03
JAEA-Review-2008-073-1.pdf:37.33MBJAEA-Review-2008-073-2.pdf:37.16MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2005 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.
Nishio, Kazuhisa; Oyama, Takuya; Mikake, Shinichiro; Mizuno, Takashi; Saegusa, Hiromitsu; Takeuchi, Ryuji; Amano, Kenji; Tsuruta, Tadahiko; Hama, Katsuhiro; Seno, Yasuhiro; et al.
JAEA-Review 2008-072, 28 Pages, 2009/02
JAEA-Review-2008-072.pdf:11.8MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named the Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at the MIU project is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following 2008 fiscal year plan based on the MIU Master Plan updated in 2002, (1) Investigation Plan, (2) Construction Plan, (3) Research Collaboration Plan, etc.
Uwaba, Tomoyuki; Ito, Masahiro*; Mizuno, Tomoyasu
Journal of Nuclear Science and Technology, 45(11), p.1183 - 1192, 2008/11
Times Cited Count：13 Percentile：66.71(Nuclear Science & Technology)Nishio, Kazuhisa; Mizuno, Takashi; Oyama, Takuya; Nakama, Shigeo; Saegusa, Hiromitsu; Takeuchi, Ryuji; Amano, Kenji; Tsuruta, Tadahiko; Hama, Katsuhiro; Iyatomi, Yosuke; et al.
JAEA-Review 2007-038, 31 Pages, 2007/12
JAEA-Review-2007-038.pdf:11.5MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three Phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the Project is under the Construction Phase. This document presents the following 2007 fiscal year plan of the Construction Phase based on the MIU Master Plan updated in 2002, (1)Investigation Plan at the MIU Construction Site, (2)Construction Plan at the MIU Construction Site, (3)Research Collaboration Plan.
Nishio, Kazuhisa; Mizuno, Takashi; Oyama, Takuya; Nakama, Shigeo; Saegusa, Hiromitsu; Takeuchi, Ryuji; Amano, Kenji; Tsuruta, Tadahiko; Hama, Katsuhiro; Iyatomi, Yosuke; et al.
JAEA-Review 2007-037, 29 Pages, 2007/12
JAEA-Review-2007-037.pdf:13.06MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three Phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the Project is under the Construction Phase. This document presents the following 2006 fiscal year plan of the Construction Phase based on the MIU Master Plan updated in 2002, (1)Investigation Plan at the MIU Construction Site, (2)Construction Plan at the MIU Construction Site, (3)Research Collaboration Plan.
Saegusa, Hiromitsu; Seno, Yasuhiro; Nakama, Shigeo; Tsuruta, Tadahiko; Iwatsuki, Teruki; Amano, Kenji; Takeuchi, Ryuji; Matsuoka, Toshiyuki; Onoe, Hironori; Mizuno, Takashi; et al.
JAEA-Research 2007-043, 337 Pages, 2007/03
JAEA-Research-2007-043.pdf:28.14MB
The Mizunami Underground Laboratory (MIU) Project is a comprehensive research project investigating the deep underground environment within crystalline rock being conducted by Japan Atomic Energy Agency at Mizunami City in Gifu Prefecture, central Japan. This report summarizes the results of the Surface-based Investigation Phase, identifies future issues and provides direction for research to be conducted during Construction Phase and Operation Phase. The results compiled in this report will be utilized for the technical knowledge base on geological disposal of HLW, and can be used to enhance the technical basis for waste disposal in general and for development of government regulations.
Yamano, Hidemasa; Fujita, Satoshi; Tobita, Yoshiharu; Kamiyama, Kenji; Kondo, Satoru; Morita, Koji*; Fischer, E. A.; Brear, D. J.; Shirakawa, Noriyuki*; Cao, X.; et al.
JNC TN9400 2003-071, 340 Pages, 2003/08
JNC-TN9400-2003-071.pdf:1.54MB
An advanced safety analysis computer code, SIMMER-III, has been developed to investigate postulated core disruptive accidents in liquid-metal fast reactors (LMFRs). SIMMER-III is a two-dimensional, three-velocity-field, multiphase, multicomponent, Eulerian, fluid-dynamics code coupled with a space-dependent neutron kinetics model. By completing and integrating all the physical models originally intended at the beginning of this code development project, SIMMER-III is now applicable to integral reactor calculations and other complex multiphase flow problems. A systematic code assessment program, conducted in collaboration with European research organizations, has shown that the advanced features of the code have resolved many of the limitations and problem areas in the previous SIMMER-II code. In this report, the models, numerical algorithms and code features of SIMMER-III Version 3.A are described along with detailed program description. Areas which require future model refinement are also discussed. SIMMER-III Version 3.A, a coupled fluid-dynamics and neutronics code system, is expected to significantly improve the flexibility and reliability of LMFR safety analyses.
Yamano, Hidemasa; Fujita, Satoshi; Tobita, Yoshiharu; Kondo, Satoru; Morita, Koji*; Sugaya, Masaaki*; Mizuno, Masahiro*; Hosono, Seigo*; Kondo, Teppei*
JNC TN9400 2003-070, 333 Pages, 2003/08
JNC-TN9400-2003-070.pdf:1.35MB
An advanced safety analysis computer code, SIMMER-III, has been developed at Japan Nuclear Cycle Development Institute (JNC) to more realistically investigate postulated core disruptive accidents in liquid-metal fast reactors. The two-dimensional framework of SIMMER-III fluid dynamics has been extended to three dimensions to a new code, SIMMER-IV, which is currently (in Version 2) coupled with the three-dimensional neutronics model. With the completion of the SIMMER-IV version, the applicability of the code is further enhanced and the many of the known limitations in SIMMER-III are eliminated. The sample calculations demonstrated the general validity of SIMMER-IV. This report describes SIMMER-IV Version 2.A, by documenting the models, numerical algorithms and code features, along with the program description and input and output information to aid the users.
Nakamura, Masahiro; Mizuno, Mineo*; Kosaka, Yuji*; Ogawa, Shinta*
JNC TJ8440 2002-003, 55 Pages, 2002/02
JNC-TJ8440-2002-003.pdf:13.04MB
no abstracts in English
kondo, Satoru; Yamano, Hidemasa; Tobita, Yoshiharu; Fujita, Satoshi; Morita, Koji*; Mizuno, Masahiro*; *
JNC TN9400 2001-003, 307 Pages, 2000/11
JNC-TN9400-2001-003.pdf:8.33MB
An advanced safety analysis computer code, SIMMER-III, has been developed at Japan Nuclear Cycle Development Institute (JNC) to more realistically investigate postulated core disruptive accidents in liquid-metal fast reactors. The two-dimensional framework of SIMMER-III fluid dynamics has been extended to three dimensions to a new code, SIMMER-IV, which is currently (in Version 1) coupled with the existing two-dimensional neutronics model. With the completion of the first SIMMER-IV version, the applicability of the code is further enhanced and the many of the known limitations in SIMMER-III are eliminated. The sample calculations demonstrated the general validity of SIMMER-IV. This report describes SIMMER-IV version 1.B, by documenting the models, numerical algorithms and code features, along with the program description and input and output information to aid the users. Further extension of the code is planned to couple the three-dimensional neutronics in the future.
