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Li, Y.; Katsumata, Genshichiro*; Masaki, Koichi; Hayashi, Shotaro*; Itabashi, Yu*; Nagai, Masaki*; Suzuki, Masahide*; Kanto, Yasuhiro*
Journal of Pressure Vessel Technology, 143(4), p.041501_1 - 041501_8, 2021/08
Times Cited Count:2 Percentile:20.79(Engineering, Mechanical)Li, Y.; Hirota, Takatoshi*; Itabashi, Yu*; Yamamoto, Masato*; Kanto, Yasuhiro*; Suzuki, Masahide*; Miyamoto, Yuhei*
JAEA-Review 2020-011, 130 Pages, 2020/09
For the improvement of the structural integrity assessment methodology on reactor pressure vessels (RPVs), the probabilistic fracture mechanics (PFM) analysis code PASCAL has been developed and improved in Japan Atomic Energy Agency based on the latest knowledge. The PASCAL code evaluates the failure probabilities and frequencies of Japanese RPVs under transient events such as pressure thermal shock considering neutron irradiation embrittlement. In order to confirm the reliability of the PASCAL as a domestic standard code and to promote the application of PFM on the domestic structural integrity assessments of RPVs, it is important to perform verification activities, and summarize the verification processes and results as a document. On the basis of these backgrounds, we established a working group, composed of experts on this field besides the developers, on the verification of the PASCAL module and the source program of PASCAL was released to the members of working group. This report summarizes the activities of the working group on the verification of PASCAL in FY2016 and FY2017.
Lu, K.; Katsuyama, Jinya; Li, Y.; Miyamoto, Yuhei*; Hirota, Takatoshi*; Itabashi, Yu*; Nagai, Masaki*; Suzuki, Masahide*; Kanto, Yasuhiro*
Mechanical Engineering Journal (Internet), 7(3), p.19-00573_1 - 19-00573_14, 2020/06
Suzuki, Masahide*; Murakami, Kenta*; Suzuki, Takashi*; Okayama, Ryuta*; Katsuyama, Jinya; Li, Y.
E-Journal of Advanced Maintenance (Internet), 11(4), p.172 - 178, 2020/02
no abstracts in English
Matsumura, Taichi; Nagaishi, Ryuji; Katakura, Junichi*; Suzuki, Masahide*
Radiation Physics and Chemistry, 166, p.108493_1 - 108493_9, 2020/01
Times Cited Count:2 Percentile:12.16(Chemistry, Physical)In this work, when radiation sources of Cs, Sr and Y were assumed to be put in the front of a plain SUS304 plate as a typical material submerged in water, energy spectra of secondary photons and electrons at the front and back sides of plate were simulated with changing the thickness of plate, and spacing between the source and plate by using a Monte Carlo calculation code of PHITS. In the case of Cs gamma-ray (monochromatic 662 keV), the energy spectra at the front side was smaller than those at the back side due to the existence of plate. Then the dependence of spectra on the plate thickness was observed more clearly at the back side than at the front side. It was clearly shown how the energy spectra of photons and electrons varied with the incident radiation type, the spacing, and the thickness.
Lu, K.; Katsuyama, Jinya; Li, Y.; Miyamoto, Yuhei*; Hirota, Takatoshi*; Itabashi, Yu*; Nagai, Masaki*; Suzuki, Masahide*; Kanto, Yasuhiro*
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 9 Pages, 2019/05
Miradji, F.; Suzuki, Chikashi; Nishioka, Shunichiro; Suzuki, Eriko; Nakajima, Kunihisa; Osaka, Masahiko; Barrachin, M.*; Do, T. M. D.*; Murakami, Kenta*; Suzuki, Masahide*
Proceedings of 9th Conference on Severe Accident Research (ERMSAR 2019) (Internet), 21 Pages, 2019/03
Matsumura, Taichi; Nagaishi, Ryuji; Katakura, Junichi*; Suzuki, Masahide*
Nuclear Science and Engineering, 192(1), p.70 - 79, 2018/10
Times Cited Count:1 Percentile:11.49(Nuclear Science & Technology)The gamma-scanning of SDS (submerged demineralizer system) vessel used as a typical vessel for decontamination of radioactive water at Three Mile Island Unit 2 (TMI-2) accident was simulated in the axial and radial directions of real and cylindrical-shaped vessels by using a Monte Carlo calculation code (PHITS) on the basis of the geometrical and compositional information of vessel and gamma-scanning available in the previous reports at the accident. In the axial simulation, the true distribution of radioactive Cs in the zeolite packed bed of vessel was successfully evaluated when a correction function derived from a virtual constant distribution of Cs was applied to the reported gamma-scanning profile. In the radial simulation, the virtual disk-formed and shell-formed sources of Cs displaced in the packed bed were clearly observed from the top and bottom views of vessel. This new radial gamma-scanning indicates that the radial localization of Cs could be well observed by measuring gamma-ray from the top view of vessel during storage. We further examined the radial gamma-scanning from the side view whether the radial localization of Cs can be confirmed in the normally existing gamma-scanning room or not.
Li, Y.; Katsumata, Genshichiro*; Masaki, Koichi*; Hayashi, Shotaro*; Itabashi, Yu*; Nagai, Masaki*; Suzuki, Masahide*; Kanto, Yasuhiro*
Proceedings of 25th International Conference on Nuclear Engineering (ICONE-25) (CD-ROM), 10 Pages, 2017/07
In Japan, a PFM analysis code PASCAL (PFM Analysis of Structural Components in Aging LWR) has been developed by the Japan Atomic Energy Agency to evaluate the through-wall cracking frequencies of Japanese reactor pressure vessels (RPVs) considering neutron irradiation embrittlement and pressurized thermal shock transients. In this study, as a part of the verification activities, a working group was established in Japan, with seven organizations from industry, universities and institutes voluntarily participating as members. The source program of PASCAL was released to the members of the working group. Through one year activities, the applicability of PASCAL for structural integrity assessments of domestic RPVs was confirmed with great confidence. This paper presents the details of the verification activities of the working group including the verification plan, approaches and results.
Li, Y.; Hayashi, Shotaro*; Itabashi, Yu*; Nagai, Masaki*; Kanto, Yasuhiro*; Suzuki, Masahide*; Masaki, Koichi*
JAEA-Review 2017-005, 80 Pages, 2017/03
For the improvement of the structural integrity assessment methodology on reactor pressure vessels (RPVs), the probabilistic fracture mechanics (PFM) analysis code PASCAL has been developed and improved in JAEA based on latest knowledge. The PASCAL code evaluates the failure probabilities and frequencies of Japanese RPVs under transient events such as pressurized thermal shock considering neutron irradiation embrittlement. In order to confirm the reliability of the PASCAL as a domestic standard code and to promote the application of PFM on the domestic structural integrity assessments of RPVs, it is important to verify the probabilistic variables, functions and models incorporated in the PASCAL and summarize the verification processes and results as a document. On the basis of these backgrounds, we established a working group, composed of experts on this field besides the developers, on the verification of the PASCAL3 which is a PFM analysis module of PASCAL, and the source program of PASCAL3 was released to the members of working group. Through one year activities, the applicability of PASCAL in structural integrity assessments of domestic RPVs was confirmed with great confidence. This report summarizes the activities of the working group on the verification of PASCAL in FY2015.
Tobita, Toru; Nakagawa, Sho*; Takeuchi, Tomoaki; Suzuki, Masahide; Ishikawa, Norito; Chimi, Yasuhiro; Saito, Yuichi; Soneda, Naoki*; Nishida, Kenji*; Ishino, Shiori*; et al.
Journal of Nuclear Materials, 452(1-3), p.241 - 247, 2014/09
Times Cited Count:17 Percentile:76.64(Materials Science, Multidisciplinary)Three kinds of Fe-based model alloys, Fe-0.018 atomic percent (at.%) Cu, Fe-0.53at.%Cu, and Fe-1.06at.%Cu were irradiated with 2 MeV electrons up to the dose of 210 dpa at 250C. After the irradiation, the increase in Vickers hardness and the decrease in electrical resistivity were observed. The increase in hardness by electron irradiation is proportional to the product of the Cu contents and the square root of the electron dose. The decrease in electrical resistivity is proportional to the product of the square of Cu contents and the electron dose. Cu clustering in the materials with electron irradiation and thermal aging was observed by means of the three dimensional atom probes (3D-AP). The change in Vickers hardness and electrical resistivity is well correlated with the volume fraction of Cu clusters.
Takeuchi, Tomoaki; Kakubo, Yuta*; Matsukawa, Yoshitaka*; Nozawa, Yasuko*; Toyama, Takeshi*; Nagai, Yasuyoshi*; Nishiyama, Yutaka; Katsuyama, Jinya; Yamaguchi, Yoshihito; Onizawa, Kunio; et al.
Journal of Nuclear Materials, 452(1-3), p.235 - 240, 2014/09
Times Cited Count:40 Percentile:95.16(Materials Science, Multidisciplinary)Microstructures and hardness of stainless steel weld overlay cladding of reactor pressure vessels subjected to the thermal aging at 400 C for 100-10,000 h were investigated using atom probe tomography and nanoindentation technique. The Cr concentration fluctuation in the -ferrite phase caused by spinodal decomposition rapidly progressed by the 100 h aging while NiSiMn clusters increased in number density at 2,000 h and coarsened at 10,000 h. The hardness of the -ferrite phase also rapidly increased at the short aging time. The Cr concentration fluctuation and the hardness were in good correlation with the degree of the Cr concentration fluctuation rather than the formation of the NiSiMn clusters. These results strongly suggested that the dominant factor of the hardening of the -ferrite phase by the thermal aging was Cr spinodal decomposition.
Takeuchi, Tomoaki; Kakubo, Yuta*; Matsukawa, Yoshitaka*; Nozawa, Yasuko*; Nagai, Yasuyoshi*; Nishiyama, Yutaka; Katsuyama, Jinya; Onizawa, Kunio; Suzuki, Masahide
Journal of Nuclear Materials, 443(1-3), p.266 - 273, 2013/11
Times Cited Count:16 Percentile:76.68(Materials Science, Multidisciplinary)Investigation on irradiation effects of weld-overlay claddings is necessary for safety assessment of reactor pressure vessels. We investigated microstructural changes in the cladding, which was composed of about 90% austenite and 10% -ferrite phases, subjected to the neutron irradiation to 7.210 n/cm at 290C, by 3D atom probe tomography technique. In the ferrite phase, the amplitude of the Cr and Si concentration fluctuation was increased by the irradiation and Ni and Mn concentration fluctuations were newly occurred. In the austenite phase, '(NiSi) -like clusters were formed. In contrast, the results of our previous work on the cladding subjected to thermal aging showed the amplitude of the Cr fluctuation was significantly increased and G (Ni-Si-Mn) phase was formed in the ferrite phase. Moreover, no changes were observed in the austenite by the aging.
Seguchi, Tadao*; Tamura, Kiyotoshi*; Watashi, Katsumi; Suzuki, Masahide; Shimada, Akihiko; Sugimoto, Masaki; Idesaki, Akira; Yoshikawa, Masahito; Oshima, Takeshi; Kudo, Hisaaki*
JAEA-Research 2012-029, 158 Pages, 2012/12
The degradation mechanisms of ethylene-propylene rubber (EPR), crosslinked polyethylene (XLPE), polyvinylchloride (PVC), and silicone rubber (SiR) as the cable insulation materials were investigated for the cable ageing research of the nuclear power plant. The materials as same insulations for the practical cable (practical formulation) and as the model formulation containing specific additive were selected. They were exposed to the accelerated radiation and thermal environments. The mechanical properties, the crosslinking and chain scission, and the distribution of antioxidant and of oxidative products were measured and analyzed.
Ishihara, Masahiro; Ishitsuka, Etsuo; Suzuki, Masahide
JAEA-Conf 2012-002, 179 Pages, 2012/12
Under the "Arrangement for Corporation in the field of peaceful uses of Nuclear Energy between the Japan Atomic Energy Agency (JAEA) and the Korean Atomic Energy Research Institute (KAERI)", the 2012 JAEA/KAERI Joint Seminar on Advanced Irradiation and PIE (post-irradiation examination) Technologies has been held at Mito, Japan from March 28 to 30, 2012. This triennial seminar is the seventh in series of bilateral exchange of irradiation and PIE technologies and research reactor management. Since the first joint seminar on the PIE Technology between JAERI (Japan Atomic Energy Research Institute, former agency of JAEA) and KAERI was held at JAERI Oarai Research Institute, Japan in 1992, the international cooperation program between JAEA and KAERI has been actively carried out in the field of neutron irradiation. At the fifth seminar in 2005 and sixth in 2008, the irradiation technology and the research reactor management fields were included, respectively, to the joint seminar, and it covers whole areas of irradiation using research reactors. In this seminar total 37 presentations were made in three technical sessions, which are "research reactor management", "advanced irradiation technology" and "post-irradiation examination technology", and active information exchange was done among participants. Papers or manuscripts presented in the 2012 JAEA/KAERI Joint Seminar on Advanced Irradiation and PIE Technologies are contained in the proceedings.
Ishihara, Masahiro; Kimura, Nobuaki; Takemoto, Noriyuki; Ooka, Makoto; Kaminaga, Masanori; Kusunoki, Tsuyoshi; Komori, Yoshihiro; Suzuki, Masahide
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 7 Pages, 2012/10
The JMTR has been utilized for fuel/material irradiation examinations of LWRs, HTGR, fusion reactor as well as for RI productions. The refurbishment of the JMTR was started from the beginning of JFY 2007, and finished in March 2011 as planned schedule. Unfortunately, at the end of the JFY 2010 on March 11, the Great-Eastern-Japan-Earthquake occurred, and functional tests before the JMTR restart were delayed by the earthquake. Moreover, a detail inspection found some damages such as small cracks in the concrete structure, ground sinking around the reactor building. Consequently, the restart will delay from June 2011. Now, the safety evaluation of the facility after the earthquake disaster is being carried out aiming at the restart of the JMTR. The renewed JMTR will be started from JFY 2012 and operated for a period of about 20 years until around JFY 2030. The usability improvement of the JMTR is also discussed with users as the preparations for re-operation.
Ishitsuka, Etsuo; Ishihara, Masahiro; Suzuki, Masahide
JAEA-Review 2012-030, 247 Pages, 2012/07
This report summarizes the documents presented in the Specialist Meeting on Mo Production by (n,) Method, which was held on March 9 to 10, 2012, at the Yurakucho Asahi Hall in Tokyo, hosted by Japan Atomic Energy Agency. The objective of the meeting is to exchange the information of current status, future plan for the Mo production, and to make a discussion of "How to cooperate" in each research and test reactors. There were 27 participants from Poland, Kazakhstan, Indonesia, Thailand, Malaysia, Netherlands, Korea and Japan. As a result of this meeting, it was recognized that to push forward the development of Mo production by (n,) method is necessary for the future steady supply of Mo. Moreover, an irradiation test using the high density MoO pellet developed by the Japan Atomic Energy Agency was proposed from a viewpoint of a merit for the common irradiation target in each research and test reactors.
Takemoto, Noriyuki; Hori, Naohiko; Nakagawa, Shigeaki; Ishitsuka, Etsuo; Kaminaga, Masanori; Nurzhan, S.*; Takibayev. N.*; Aliyev, B.*; Suzuki, Masahide
Proceedings of International Conference of Young Scientists and Specialists; Current Issues on the Peaceful Use of Atomic Energy (Internet), p.17 - 27, 2012/06
The JMTR is expected to be a key infrastructure with related facilities to contribute the nuclear Human Resource Development (HRD) by a research and On-the-Job-Training (OJT) in order to support global expansion of nuclear power industry. The training program for Asian young researchers and engineers were started from JFY 2011 in JAEA, and 10 trainees from Kazakhstan and Thailand had studied in JFY 2011. In addition, the training course was newly established for domestic students and young engineers from JFY 2010 to JFY 2012, and 45 domestic students and engineers were studied in the course from JFY 2010 to JFY 2011.
Ishihara, Masahiro; Suzuki, Masahide
JAEA-Conf 2011-003, 297 Pages, 2012/03
This report is the Proceedings of the 4th International Symposium on Materials Testing Reactors hosted by Japan Atomic Energy Agency (JAEA). The 4th symposium was originally scheduled to be held INVAP in Argentina. However, the aftermath of volcanic explosion at Chili forced the symposium to change place. Total 111 participants attended from Argentina, Belgium, France, Germany, Indonesia, Malaysia, Korea, South Africa, Switzerland, the United State and Japan. This symposium addressed the general topics of "status and future plan of materials testing reactors", "advancement of irradiation technology", "expansion of industry use(RI)", "facility, upgrade, aging management", "new generation MTR", "advancement of PIE technology", "development of advanced driver fuel", and "nuclear human resource development(HRD) for next generation", and 39 presentations were made.
Takemoto, Noriyuki; Izumo, Hironobu; Hori, Naohiko; Ishitsuka, Etsuo; Suzuki, Masahide
JAEA-Conf 2011-003, p.265 - 269, 2012/03
The JMTR is expected to be a key infrastructure to contribute the nuclear Human Resource Development (HRD) by a research and On-Job-Training (OJT) in order to support global expansion of nuclear power industry. The training program for Asian young researchers and engineers were started from JFY 2011 in JAEA, and ten trainees from Kazakhstan and Thailand had attended in this program in JFY 2011. In addition, in the nuclear HRD initiative program sponsored by the MEXT, the training course was newly established for domestic students and young engineers from JFY 2010 to JFY 2012. In this course, basic understanding on irradiation test and post irradiation examination is aimed to achieve by overall and practical training such as the neutronic/thermal designs of irradiation capsule, post irradiation examination, measurement and evaluation of neutron fluence, etc. using the JMTR and the related facilities. The 1st training course was held with 10 trainees in JFY 2010. The 2nd and 3rd training courses were also held with 19 trainees and 16 trainees in JFY 2011. From JFY 2012, two courses will be held in every year, and 20 trainees will be accepted in each course.