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Hemmi, Tsutomu*; Harjo, S.; Kajitani, Hideki*; Suwa, Tomone*; Saito, Toru*; Aizawa, Kazuya; Osamura, Kozo*; Koizumi, Norikiyo*
IEEE Transactions on Applied Superconductivity, 27(4), p.4200905_1 - 4200905_5, 2017/06
Times Cited Count:2 Percentile:7.50(Engineering, Electrical & Electronic)Harjo, S.; Hemmi, Tsutomu; Abe, Jun; Gong, W.; Nunoya, Yoshihiko; Aizawa, Kazuya; Ito, Takayoshi*; Koizumi, Norikiyo; Machiya, Shutaro*; Osamura, Kozo*
Materials Science Forum, 777, p.84 - 91, 2014/02
Times Cited Count:2 Percentile:70.97(Materials Science, Multidisciplinary)Hemmi, Tsutomu; Harjo, S.; Kajitani, Hideki; Nabara, Yoshihiro; Takahashi, Yoshikazu; Nunoya, Yoshihiko; Koizumi, Norikiyo; Abe, Jun; Gong, W.; Aizawa, Kazuya; et al.
KEK Progress Report 2013-4, p.45 - 47, 2013/11
The gradual degradation was observed in the results for ITER CS conductor samples. To investigate its origin, the internal strain in the sample after the testing was successfully measured using a neutron diffraction technique non-destructively. Up to now, the transverse electromagnetic loading has been considered as an origin of the degradation due to the local bending at the high loading side (HLS). However, as a result of the neutron diffraction measurement, the large bending at the LLS of the HFZ was found. The large bending was considered as an origin of the strand buckling due to the large void generated by the transverse electromagnetic loading and the thermally induced residual compressive strain. For the improvement of the conductor performance on the strand buckling, the shorter twisting pitch (STP) can be considered. The result of the SULTAN testing of the conductor sample with STP found very effective, and the performance degradation was negligible.
Hemmi, Tsutomu; Harjo, S.; Nunoya, Yoshihiko; Kajitani, Hideki; Koizumi, Norikiyo; Aizawa, Kazuya; Machiya, Shutaro*; Osamura, Kozo*
Superconductor Science and Technology, 26(8), p.084002_1 - 084002_6, 2013/08
Times Cited Count:17 Percentile:55.88(Physics, Applied)JAEA has responsibly to procure all ITER CS conductors. Several conductor samples was fabricated and tested. From the result of the cyclic testing in first conductor sample named JACS01 and second conductor sample named JACS02, the continuous linear degradation of the current sharing temperature () was observed. To investigate the
degradation, the visual inspection of JACS01 right leg was performed. As a result, the large deflection at the lower loading side (LLS) in the high field zone (HFZ) was observed. The bending strain of the strands cannot be evaluated from the only deflection obtained by a visual inspection. To evaluate the strain of strands in the conductor sample quantitatively, the neutron diffraction measurement of JACS01 left leg was performed using the engineering materials diffractometer in J-PARC. From the result, the large bending strain at the LLS in the HFZ was observed. Therefore, the degraded position in the conductor sample can be determined.
Kobayashi, Takanori; Sakon, Miyoji; Takada, Osamu; Hatori, Masakazu; Sakamoto, Tsutomu; Sato, Toshiyuki; Kazama, Akihito*; Ishizawa, Yoshihiro*; Igawa, Katsuhisa*; Nakae, Hideo*
JAEA-Review 2011-047, 48 Pages, 2012/02
I confirmed a leak of the effluent gas from cylinder part during a load examination after the check of the emergency generator C unit on December 28, 2010 of the facilities check average and confirmed crack in No.8 cylinder liner part. As a result, because it was not performed oil pressure management properly without attaching an oil pressure gauge when I removed cylinder liner about the cause, crack occurred by having been able to write excessive stress for the cylinder liner and reached damage. By a process of this investigation, a fall of the materials strength of some cylinder liner was confirmed, but because a lead ingredient got mixed with materials by a casting process at the time of the production of the cylinder liner, as for this, Widmannst tten graphite occurred, and it became clear that materials strength fell. In addition, I performed inspection by the supersonic wave velocity measurement as technique to distinguish this Widmannst tten graphite easily and confirmed that I was effective.
Hemmi, Tsutomu; Harjo, S.; Ito, Takayoshi; Matsui, Kunihiro; Nunoya, Yoshihiko; Koizumi, Norikiyo; Takahashi, Yoshikazu; Nakajima, Hideo; Aizawa, Kazuya; Suzuki, Hiroshi; et al.
IEEE Transactions on Applied Superconductivity, 21(3), p.2028 - 2031, 2011/06
Times Cited Count:10 Percentile:49.18(Engineering, Electrical & Electronic)Residual strain in conductors is caused by the difference in the coefficient of expansion between NbSn strands and the jacket over a temperature range of 5 - 923 K. The superconducting properties of strands vary significantly, depending on the strain. It is important to clarify the residual strain as part of the evaluation of superconducting performance. However, the residual strain of strands in the conductor has not been measured so far because of their complicated configuration and their location in a jacket. The engineering materials diffractometer "Takumi" in J-PARC can measure residual strain with a relative accuracy of around 0.02%, using neutron diffraction. In this study, the Takumi was applied to the measurement of residual strain in strands for the ITER TF conductor. Results indicate that the residual strain of strands in the conductor can be determined, thereby clarifying the mechanism of residual strain and its relationship to superconducting performance.
Ito, Takayoshi; Harjo, S.; Osamura, Kozo*; Hemmi, Tsutomu; Awaji, Satoshi*; Machiya, Shutaro*; Oguro, Hidetoshi*; Nishijima, Gen*; Takahashi, Koki*; Matsui, Kunihiro; et al.
Materials Science Forum, 681, p.209 - 214, 2011/05
Times Cited Count:1 Percentile:51.12(Materials Science, Multidisciplinary)Tanaka, Masaru*; Gofuku, Akio*; Ishizaka, Kaoru*; Tokizawa, Takayuki; Sato, Kazuhiko; Koga, Osamu
JAEA-Research 2010-054, 76 Pages, 2011/02
To obtain public understanding on the uranium mining sites reclamation at Ningyo-toge Environmental Engineering Center, it is necessary to conduct appropriate Risk Communication (RC). In this study, to discuss the appropriate Risk communication method on the uranium mining sites reclamation, making of explanatory material by university student, and questionnaire survey on the risk perception were conducted.
Matsui, Yoshinori; Takahashi, Hiroyuki; Yamamoto, Masaya; Nakata, Masahito; Yoshitake, Tsunemitsu; Abe, Kazuyuki; Yoshikawa, Katsunori; Iwamatsu, Shigemi; Ishikawa, Kazuyoshi; Kikuchi, Taiji; et al.
JAEA-Technology 2009-072, 144 Pages, 2010/03
"R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant" was carried out from FY2006 in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupled irradiations or single irradiation by JOYO fast reactor and JRR-3 thermal reactor were performed for about two years. The irradiation specimens are very important materials to establish of "Evaluation of Irradiation Damage Indicator" in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we summarized about the overall plan, the work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research-and-Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency.
Ishizaka, Kaoru*; Tanaka, Masaru*; Suzuki, Kazuhiko*; Tokizawa, Takayuki; Sato, Kazuhiko; Koga, Osamu
JAEA-Research 2008-086, 64 Pages, 2008/12
In this study, to discuss the appropriate Risk Communication (RC) method on the uranium mining sites reclamation, comparative investigation of RC cases which concern the siting of solid waste management facilities and nuclear facilities, and questionnaire survey on the risk perception of landfill were conducted. As a result of comparative investigation, information disclosure and supplement are important factor to obtain public trust on the siting plan and developer. As assumption of the public participation, it is necessary the safety assurance of the siting plan and regional development plan cover a long period. As a result of questionnaire survey, it was shown that the almost people worried about health and the environmental impact of radioactive waste; moreover, there are a lot of ratios of the peoples who felt a dangerous and scary sensuously.
Yabuta, Naohiro*; Kawai, Jun*; Hikawa, Tamae*; Tokizawa, Takayuki; Sato, Kazuhiko; Koga, Osamu
JAEA-Review 2008-015, 92 Pages, 2008/11
On the closure of uranium mine site at Ningyo-Toge Environmental Engineering Center Japan Atomic Energy Agency, the action plans for risk communication with residence and local governments were developed and implemented. Under a practical program of the risk communication, an ethnographical research on Ningyo-Toge Environmental Engineering Center has been conducted by local high school students. The research was focused on several social groups such as engineers at the Center and residents around Ningyo-Toge and described their circumstances from the past to the present, since the discovery of the uranium outcrop 1955. In the second year of the program, the results of the research were presented at symposium and the students had opportunities to exchange their views with others from different high schools that held in similar programs. Through those activities, the importance of the program was rediscovered and some new issues were also identified.
Yabuta, Naohiro*; Kawai, Jun*; Hikawa, Tamae*; Tokizawa, Takayuki; Sato, Kazuhiko; Koga, Osamu
JAEA-Review 2008-014, 133 Pages, 2008/11
On the closure of uranium mine site at Ningyo-Toge, the action plans for risk communication with residence and local governments were developed and implemented. Under a practical program of the risk communication, an ethnographical research on Ningyo-toge has been conducted by local high school students. The research was focused on several social groups such as engineers at the Center and residents around Ningyo-toge and described their circumstances from the past to the present. In addition, it should be noted that as a results, the research project led several effects listed below; (1) High school students understood significance of the uranium development projects implemented at Ningyo-toge, (2) Differences of standpoints between local residents and Ningyo-toge became clearer, (3) Foundation to communicate between local communities and Ningyo-toge was found out, (4) The educational program on an ethnographical research was conducted autonomously by local high school students.
Aizawa, Kosuke; Nakanishi, Shigeyuki; Yamano, Hidemasa; Kotake, Shoji; Hayakawa, Satoshi*; Watanabe, Osamu*; Fujimata, Kazuhiro*
Proceedings of 6th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-6) (USB Flash Drive), 7 Pages, 2008/11
To evaluate the flow-induced vibration in the actual-sized pipings of JSFR, computer simulation is necessary. In this study, as the first step, sensitivity analysis of turbulence flow models for unsteady short-elbow pipe flow has been carried out with the STAR-CD thermal-hydraulic simulation code. Through the sensibility analysis, the objective of this study is to propose the best analysis models which can reproduce the unsteady characteristics obtained in the 1/3-scale test results with 9.2 m/s of main flow. In this study, to take into account anisotropic characteristics of turbulence, two turbulent flow models were used: large eddy simulation (LES) and Reynolds stress model (RSM). The both validated simulations have reproduced flow separation region and periodic vortex shedding. The simulation results with both models were compared with power spectrum densities of pressure fluctuations which were used in the pipe vibration evaluation. Only the RSM simulation with the best combination has reproduced the pressure-fluctuation power spectrum densities, which were characterized by a peak frequency of 10 Hz in the 1/3 test with 9.2 m/s.
Terakado, Tsuguo; Izawa, Osamu
UTNL-R-0466, p.8_1 - 8_11, 2008/03
no abstracts in English
Hirota, Masahiro*; Kurihara, Osamu; Takada, Chie; Takasaki, Koji; Momose, Takumaro; Deji, Shizuhiko*; Ito, Shigeki*; Saze, Takuya*; Nishizawa, Kunihide*
Health Physics, 93(1), p.28 - 35, 2007/07
Times Cited Count:4 Percentile:30.70(Environmental Sciences)A new Am lung monitoring system without shielding was devised by using an imaging plate system. The Lawrence Livermore National Laboratory's realistic torso phantom containing a
Am lung was covered by imaging plates sealed in lightproof bags. The imaging plate system displayed
Am lung images characteristic of the lung shape of the torso phantom. The imaging plate system's lower detection limits of 14 Bq for 60 min exposure and 6 Bq for 300 min were the same levels as those of the phoswich detectors and the germanium detectors placed in shielded rooms. The imagingplate system for 60 min exposure detected about 2% of the annual limit of 740 Bq for
Am inhalation. A lung monitoring system using imaging plates is applicable for
Am lung monitoring.
Koga, Osamu; Nagara, Shuichi; Sato, Kazuhiko; Tokizawa, Takayuki
JNC TN6410 2005-001, 38 Pages, 2005/03
Mesh models are formed to carry out simulations of the groundwater flow and the solute transport at around former Yotsugi Open-Pit Mine and Yotsugi Mill Tailings Dam. Also, hydraulic field survey and literature survey are carried out to set boundary conditions and property values for the simulations.Mesh models are formed for Yotsugi Open-Pit Mine, Yotsugi Mill Tailings Dam and the wide area so that boundary conditions could be given to the model for Yotsugi Mill tailings Dam. These three models are confirmed to perform properly for analyses.Hydraulic field survey is carried out in the wide area to estimate the groundwater distribution and to understand the top hydraulic head boundary of the model. As result, groundwater level at the ridge used as a boundary of the model is set to be twenty meters depth.Values of effective diffusion coefficient, specific storage and absolute density are set to be used for the simulation of the solute transport by the literature survey.
Terakado, Tsuguo; Morimoto, Makoto; Izawa, Osamu; Ishida, Koichi; Hoshino, Katsuaki; Suzuki, Shinya; Ito, Hideaki; Aoki, Hiroshi; Odo, Toshihiro
JNC TN9430 2004-003, 87 Pages, 2004/03
This paper describes the results of Secondary Cooling System main pumps test ,which were done as a part of JOYO MK-3 function test. The function tests were cexcuted to get the operating characteristics of secondary cooling system, after the Intermediate Heat Exchangers, Dump Heat Exchangers, secondary main pump motors, pump speed control board and rheostat were replaced in the MK-3 conversion. These tests are composed of six items. These tests purpose are confirmed in the function of the Main pumps, sodium purification system and argon cover gas pressure control system in Secondary Cooling System. (1) SKS-205-1: flow control test, (2) SKS-205-2: flow coast down characteristics test, (3) SKS-205-3: running operation test, (4) SKS-205-4: pump vibration measurement test, (5) SKS-212: secondary sodium purification system electromagnetic-pump flow control test, (6) SKS-213: argon cover gas pressure in secondary cooling system pressure control test function tests are satisfied the design criteria. We have confirmed the system performance of the main pump, secondary sodium purification system and argon cover gas pressure control system in the Secondary Cooling System after the MK-3 conversion.
Annen, Sotonori; Tokizawa, Takayuki; Takanobu, Osamu; Takahashi, Makoto; Zaitsu, Tomohisa
JNC TN6400 2004-003, 57 Pages, 2004/03
The Ningyo-toge Environmental Engineering Center, the Japan Nuclear Cycle Development Institute had carried out research and development projects related to the front-end of the nuclear fuel cycle and has shifted its project to the environmental protection measures including decommissioning and dismantling facilities since reorganization in 1998. It was decided by the Japanese Government that a new entity would be established merging JNC and Japan Atomic Energy Research Institute, within the context of the overall reform of government-funded organizations by 2005. This draft of prospective plan of the Ningyo-toge has discussed because we are in the preparation phase for the merger with the discussion being made on the role and management of the new entity.
Sakamoto, Yukio; Sato, Osamu*; Tsuda, Shuichi; Yoshizawa, Nobuaki*; Iwai, Satoshi*; Tanaka, Shunichi; Yamaguchi, Yasuhiro
JAERI 1345, 103 Pages, 2003/01
no abstracts in English
Shimakawa, Takashi*; Watanabe, Osamu*; Kasahara, Naoto; Kobayashi, Kenichi*; Takizawa, Masaaki*; Asada, Seiji*
Proceedings of JPVRC Symposium 2002, p.87 - 95, 2002/00
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