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Yasuda, Ryo; Nitto, Koichi*; Konagai, Chikara*; Shiozawa, Masahiro*; Takenaka, Nobuyuki*; Asano, Hitoshi*; Murakawa, Hideki*; Sugimoto, Katsumi*; Nojima, Takehiro; Hayashida, Hirotoshi; et al.
Nuclear Instruments and Methods in Physics Research A, 651(1), p.268 - 272, 2011/09
Times Cited Count：7 Percentile：45.77(Instruments & Instrumentation)Neutron radiography is one of useful tools to visualize water behavior in fuel cells under operation. In order to observe the detailed information about the water distribution in MEA and GDL in fuel cells, a high spatial resolution and high sensitivity neutron imaging system are required. We developed an imaging system using the neutron color imaging intensifier and continuously observed water distribution in operating a fuel cell. By using the system, a small type fuel cell under operation was continuously observed at the TNRF in every 20 sec. In the results, the water area was appeared from GDL and MEA, and expanded to the channel of the cathode side. On the other hand, voltage was gradually reduced with the operation time, and steeply dropped. It is considered that voltage drop was caused by blockage of gas flow due to the piling up water in the channel of the cathode side.
Ishii, Takahiro; Shimizu, Kazuyuki; Sakai, Katsumi; Inami, Shinichi
Dai-7-Kai Saishori, Risaikuru Bukai Semina Tekisuto, p.172 - 173, 2011/01
The automatic fire alarm system installed in the Tokai Reprocessing Plant consists of more than 5,000 detectors in about 40 facilities for the moment. In this system, 57 non-fire cases have occurred for about 10 years from January 2001 to December 2010. and about half of these cases was due to the condensation of water vapor generated on the sensor. Therefore, the prevention of condensation is necessary to reduce such false alarms, and the measure for prevention of condensation has been taken by installing a mount for the detector basement. This mount facilitates that the detector does not contact directly to the surface of ceiling where is likely to change an environment due to changeable temperature and humidity. As a result, false alarms caused by condensation have not been found on the detectors with the mounts. This paper reports the details of the improved fire alarm system, and cause/measures for false alarms.
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.
Ishii, Takahiro; Shimizu, Kazuyuki; Sakai, Katsumi; Inami, Shinichi
Nihon Hozen Gakkai Dai-6-Kai Gakujutsu Koenkai Yoshishu, p.289 - 293, 2009/08
The automatic fire alarm system installed in the Tokai Reprocessing Plant consists of more than 5000 detectors in about 40 facilities for the moment. In this system, 51 non-fire cases have occurred for 8 years; 2001 Jan. to 2009 May, and about half of these cases was due to the condensation of water vapor generated on the sensor. Therefore, the prevention of condensation is necessary to reduce such false alarms, and the measure for prevention of condensation has been taken by installing a mount for the detector basement. This mount facilitates that the detector does not contact directly to the surface of ceiling where is likely to change an environment due to changeable temperature and humidity. As a result, false alarms caused by condensation have not been found on the detectors with the mounts. This paper reports the details of the improved fire alarm system, and cause/measures for false alarms.
O
type scintillation converter for neutron imagingYasuda, Ryo; Katagiri, Masaki; Iikura, Hiroshi; Sakai, Takuro; Hayashida, Hirotoshi; Sugimoto, Katsumi*; Takenaka, Nobuyuki*; Matsubayashi, Masahito
no journal, ,
Scintillation converter is one of important devices, which determine the spatial resolution in NRG using camera system. We prepared 10BO type with different thickness and evaluated the characteristics including spatial resolution. Those scintillators were tested using cooled type CCD camera system at thermal neutron radiography facility (TNRF) in JRR-3. Spatial resolution of those scintillators was evaluated as "half value" by the edge spread function method using knife-edged Gd plate with 0.1mm in thickness. The results show that the spatial resolution of the10BO type scintillators is improved with thinning the scintillation layer and is not so different from that of LiF type ones. On the other hand, luminescence intensity of the 10BO type scintillators is decreased with thinning the scintillation layer due to the reduction of efficiency of neutron capture and lower than that of LiF type ones.
Takahiro, Katsumi*; Ono, Yasuharu*; Ozaki, Koichi*; Kawatsura, Kiyoshi*; Narumi, Kazumasa; Sakai, Seiji; Naramoto, Hiroshi*; Yamamoto, Shunya; Nagata, Shinji*
no journal, ,
no abstracts in English
Sakai, Katsumi; Tomita, Tsuneo; Shimizu, Kazuyuki
no journal, ,
The maintenance work of many equipments such as mechanical, electrical and instrumentations installed in Tokai Reprocessing Plant has been performed more then 10,000 times per year and about 90% of maintenances were preventive work. For the maintenance management, optimization of maintenance information is required. Therefore, the aim of construction of suitable maintenance management system, Tokai Reprocessing Plant Maintenance Support System(TORMASS) was developed from 1985 to 1992. About 24,000 equipments of specifications and about 261,000 maintenance detail were registered in this system. TORMASS has been used for the repair, inspection and replacement of equipment.
Yasuda, Ryo; Sakai, Takuro; Nojima, Takehiro; Iikura, Hiroshi; Matsubayashi, Masahito; Nitto, Koichi*; Konagai, Chikara*; Shiozawa, Masahiro*; Murakawa, Hideki*; Sugimoto, Katsumi*; et al.
no journal, ,
Polymer electrolyte fuel cells (PEFC) are expected as one of the clean energy sources in next generation. The water management is one of important subjects for enhance of stability and durability of the PEFC. Neutron radiography is one of useful tools to visualize water behavior in operating fuel cells. In order to observe the detailed information about the water distribution in fuel cells, we developed an imaging system using a neutron color image intensifier which is novel neutron image detector with high spatial resolution and high sensitivity. By using the imaging system, the water distribution in a small sized fuel cell during operation was visualized. In this paper we would report results and discussion about correlation between the water behavior and fuel cell performance.
