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Imamura, Hiroaki; Suzuki, Masashi*; Shimoyama, Kazuhito; Miyakoshi, Hiroyuki
JAEA-Technology 2019-005, 163 Pages, 2019/06
For the R&D of safety enhance in future fast reactor development, the constructed the large sodium test loop (mother loop) in advanced technology experiment sodium facility (AtheNa) was completed. The sodium test loop possesses the largest capacity of about 240 tons of the world's largest sodium and can supply impurity-controlled high temperature sodium to large structural and technology demonstration test sections. It is greatly expected as R&D such as future international cooperation. For the purpose of future R&D tests, this report compiled the design specifications, fabrication and performance confirmation results of sodium test loop.
Imamura, Hiroaki; Hayakawa, Masato; Handa, Takuya*; Namiki, Katsuo*
JAEA-Technology 2015-020, 85 Pages, 2015/08
Sodium using for past experiments was maintained at the sodium technology development facility in Oarai Research and Development Center. But the oldest dump tank of the sodium was fabricated over forty years ago. It is necessary to keep it safer and more stable condition. Therefore transportation of the sodium from the facility to a new facility was planned not only to keep it safer and more stable condition but also to reuse it for other sodium experiments. Such a large amount of sodium has never been transported between two facilities in Japan. Pipe transportation between two facilities was selected by considering safety, operating efficiency and cost. The transportation equipment with over 200 meters long pipes was constructed and sodium transportation was operated. Total amount of the transported sodium was about 270 m and the flow rate was 12m/h on average.
; ; Yamada, Takeshi; ; ; ; Kaito, Yasuaki; ; Kotaka, Yoshinori; ; et al.
PNC TN2410 96-005, 339 Pages, 1996/03
Construction of the 'Monju' fuel handling systems was completed in April, 1992. From March 1991 to August 1992, pre-commissioning tests were carried out. In December 1992, all the systems of Monju were transfered to PNC, and commissioning tests and reactor physics tests, were started. For the first time, during these physics tests, the fuel handling systems were operated for one of the commissioning tests 'Loading to Criticality', without significant problems. 168 fuel sub-assemblies were loaded into the core and the first criticality was achieved on 5th April 1994. The fuel handling systems continued in operation for the 'Loading to Full Size of the Core', power distribution test and for cleaning discharged dummy sub-assemblies. To keep these fuel handling systems working somothly and satisfactorily annual maintenance has been carried out since 1992. This paper describes the operation and maintenance experience of fuel handling systems after the pre-commissioning tests and future study items for system reliability improvement.
PNC TN9410 90-143, 74 Pages, 1990/09
Duaring 7th annual inspection period of JOYO, sodium level meters in the sodium level measuring systems were replaced for both primary pumps, pump overflow clumns and secondary dump tank due to deterioration on electrical parts and insulators. In newly designed signal processing unit, compensation method for non-lineality and temprature charactristics was introduced to minimize error. The method in the new unit is same as in long range sodium level meter for reactor vessel which was replaced at 5 th annual inspection period. This time, compensation system adopted one-loop-controlers for simplification of the system. In addition, optical fiber signal transmission system was used to protect the system from electromagnetic noise in the sodium level meter of the dump tank. New system were begun to use at 17th the duty cycle and their operating performance appeared to be excellent.
Kanda, Hironori; Onojima, Takamitsu; Suzuki, Masashi; Imamura, Hiroaki; Tanaka, Masaaki; Murakami, Satoshi*
no journal, ,
The flow rate of the primary coolant system in natural circulation decay heat removal operation is reduced much lower than that in rated operation in Next generation sodium-cooled fast reactor. The electromagnetic flow meters have uncertainty on the indicated value at low flow rates conditions. Ensuring the measurement accuracy of electromagnetic flow meter is presumed to contribute the promotion of understanding of thermal hydraulics phenomena such as natural circulation in the fast reactor. In this paper, low flow rate evaluation method has been examined preliminarily by transport time-delay analysis of temperature fluctuation in sodium circulation loop. Measured data and evaluation results from temperature fluctuations which have been acquired in sodium-loop in AtheNa, indicate that this evaluation method can be applied to estimate flow rate in natural circulation decay heat removal operation.
Suzuki, Masashi; Yoshida, Eiichi; Imamura, Hiroaki; Amano, Katsunori; Shimoyama, Kazuhito
no journal, ,
no abstracts in English
Hirabayashi, Masaru; Suzuki, Masashi; Imamura, Hiroaki
no journal, ,
no abstracts in English
Imamura, Hiroaki; Hayakawa, Masato; Suzuki, Masashi; Chinone, Masaru; Amano, Katsunori; Hirabayashi, Masaru
no journal, ,
no abstracts in English
Hata, Katsuro; Ishikawa, Nobuyuki; Uesaka, Takahiro; Sudo, Tomoyuki; Matsumoto, Masaki; Aoki, Isao; Ishizaki, Nobuhiro; Imamura, Hiroaki; Uchida, Shinichi; Kikuchi, Sakae; et al.
no journal, ,
JAEA supports the decontamination activity that the local government of Fukushima carries out. In addition, JAEA carries out instruction and the advice about decontamination. I explain the concrete-based decontamination method of the house which polluted by the accident of the nuclear power plant.
Sudo, Tomoyuki; Ishikawa, Hiroyasu; Uesaka, Takahiro*; Sonoda, Takashi; Ishikawa, Nobuyuki*; Niizato, Tadafumi; Mikake, Shinichiro; Aoki, Isao; Ishizaki, Nobuhiro; Imamura, Hiroaki; et al.
no journal, ,
JAEA is working the decontamination activity for the environmental remediation of Fukushima. In this activity, I support the decontamination activity for local governments to devise a decontamination plan and actually decontaminate. In this report, 1 introduce the technical knowhow for the decontamination activity of a house.
Abe, Hironobu; Ikeda, Koki; Mikake, Shinichiro; Nagasaki, Yasushi; Niizato, Tadafumi; Asazuma, Shinichiro; Aoki, Isao; Ishikawa, Nobuyuki; Ishikawa, Hiroyasu; Ishizaki, Nobuhiro; et al.
no journal, ,
no abstracts in English
Tanaka, Masaaki; Imamura, Hiroaki; Suzuki, Masashi; Murakami, Satoshi*
no journal, ,
In sodium-cooled fast reactors, electro-magnetic flow-meters (EMFs) installed in the cooling loops may have some degree of measurement uncertainty during the operation of the decay heat removal system by natural circulation because the flow rate in such condition is much decreased from that in the normal operation condition. Then, an evaluation technology in the low flow-rate condition complementary to the EMF has been developed. As the first trial, evaluation technology by analyzing correlations of temperature transient data on the outer surface of the pipe measured by thermo-couples at several locations along flow direction was examined in the existing sodium test loop. Preliminary evaluation results were reported and potentiality of the low flow-rate evaluation technology was confirmed.