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Shibata, Akira; Miura, Kuniaki*; Takeuchi, Tomoaki; Otsuka, Noriaki; Nakamura, Jinichi; Tsuchiya, Kunihiko
JAEA-Technology 2013-024, 21 Pages, 2013/10
JAEA-Technology-2013-024.pdf:12.62MB
In the Fukushima-Daiichi Nuclear Power Plant Accident, the measurements of water level in pressure vessel and spent fuel pool were impossible due to station blackout, and it resulted in difficulty for countermeasures against the accidents and for understanding of the situations of reactor core after accidents. Therefore, we started to develop a new water level sensor for l with high reliability, which works with small electric power. This report describes reviews of conventional water level sensor and design and production of new water level sensor. After production of the sensor, performance tests were performed between room temperature and about 95 
C, and the it was confirmed that the sensor is able to measure water level with the accuracy of 
20 mm. As the results, a perspective to use the new water level sensor as water level indicator for spent fuel pools and reactor vessels after severe accident.
Takeuchi, Tomoaki; Shibata, Akira; Nagata, Hiroshi; Miura, Kuniaki*; Sano, Tadafumi*; Kimura, Nobuaki; Otsuka, Noriaki; Saito, Takashi; Nakamura, Jinichi; Tsuchiya, Kunihiko
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 8 Pages, 2012/10
In-pile instrumentation systems in present LWR's are indispensable to monitor all situations during reactor operation and reactor shut down. However, those systems did not work sufficiently under the conditions of the severe accident at the Fukushima Dai-ichi (F1) Nuclear Power Plant. Based on instrumentation and irradiation experiences accumulated in JMTR, the developments of reactor instrumentation systems to prevent severe core damage accident in advance have been started. The development objects are water level gauge utilizing 
heating, self-powered -ray detector, hydrogen concentration gauge, and analysis system for imaging and quantification of in-reactor information using Cherenkov light.
Imaizumi, Tomomi; Miyauchi, Masaru; Ito, Masayasu; Watahiki, Shunsuke; Nagata, Hiroshi; Hanakawa, Hiroki; Naka, Michihiro; Kawamata, Kazuo; Yamaura, Takayuki; Ide, Hiroshi; et al.
JAEA-Technology 2011-031, 123 Pages, 2012/01
JAEA-Technology-2011-031.pdf:16.08MB
The number of research reactors in the world is decreasing because of their aging. However, the planning to introduce the nuclear power plants is increasing in Asian countries. In these Asian countries, the key issue is the human resource development for operation and management of nuclear power plants after constructed them, and also the necessity of research reactor, which is used for lifetime extension of LWRs, progress of the science and technology, expansion of industry use, human resources training and so on, is increasing. From above backgrounds, the Neutron Irradiation and Testing Reactor Center began to discuss basic concept of a multipurpose low-power research reactor for education and training, etc. This design study is expected to contribute not only to design tool improvement and human resources development in the Neutron Irradiation and Testing Reactor Center but also to maintain and upgrade the technology on research reactors in nuclear power-related companies. This report treats the activities of the working group from July 2010 to June 2011 on the multipurpose low-power research reactor in the Neutron Irradiation and Testing Reactor Center and nuclear power-related companies.
Nagata, Hiroshi; Yamaura, Takayuki; Naka, Michihiro; Kawamata, Kazuo; Izumo, Hironobu; Hori, Naohiko; Nagao, Yoshiharu; Kusunoki, Tsuyoshi; Kaminaga, Masanori; Komori, Yoshihiro; et al.
no journal, ,
Conceptual design of the high-performance and low-cost next generation materials testing reactor which will be assumed to introduce to the nuclear power plant introduction country started from 2010 in the JAEA. Japanese atomic energy-related companies participate in this project, and this activity role as the environmental management and nuclear human resource development for the new research reactor designs. 10 MW thermal power by plate type fuel elements and swimming pool type was assumed as a design base. High safety, high cost performance, high reactor operation rate, high technology irradiation are targets of this conceptual design.
-ray detector with Pb emitterOtsuka, Noriaki; Takeuchi, Tomoaki; Shibata, Akira; Nagata, Hiroshi; Tsuchiya, Kunihiko; Miura, Kuniaki*
no journal, ,
no abstracts in English
-ray detectorOtsuka, Noriaki; Takeuchi, Tomoaki; Shibata, Akira; Nagata, Hiroshi; Tsuchiya, Kunihiko; Miura, Kuniaki*
no journal, ,
no abstracts in English
Usami, Hiroshi; Kawamura, Hiroshi; Ooka, Makoto; Miura, Kuniaki*; Onizawa, Tatsuya*
no journal, ,
no abstracts in English
