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Kobayashi, Tetsuya; Araki, Masaaki; Oba, Toshinobu; Torii, Yoshiya; Takeuchi, Masaki*
JAEA-Conf 2011-003, p.83 - 86, 2012/03
Fukushima, Manabu; Owada, Minoru; Ota, Kazunori; Takeuchi, Masaki; Goto, Shingo; Imahashi, Masaki; Terakado, Yoshibumi
JAEA-Technology 2010-028, 24 Pages, 2010/09
JAEA-Technology-2010-028.pdf:1.01MB
The cooling tower of the JRR-3's secondary cooling system is used to emit the heat from the core into the atmosphere. The appropriate maintenance of the cooling tower has helped the safe and stable reactor operation. Temperature of the secondary coolant had controlled constantly by changing the number of cooling fans. But, just after the number of fans changed, the temperature changed transiently and consequently the reactor thermal power changed. In order to amend this some weakness, the control system has improved to change the speed of fans constantly. The maintenance and improvement activities with the records of inspection are compiled to be utilized for future work.
Oba, Toshinobu; Fukushima, Manabu; Takeuchi, Masaki; Uno, Yuki; Owada, Minoru; Terakado, Yoshibumi
JAEA-Technology 2010-020, 31 Pages, 2010/07
JAEA-Technology-2010-020.pdf:1.33MB
Japan research reactor No.3 (JRR-3) has a heavy water tank. The heavy water tank surrounds the reactor core to use thermalize neutrons for experiments. The heavy water cooling system removes the heat generated by 
ray in the heavy water reflector. The heavy water cooling system is composed of the cooling system and the helium gas system. The helium gas system has an important role of helium gas circulation. The helium gas system also has a role to recombine deuterium gas and oxygen gas. We had overhauled the helium compressor regularly and replaced consumable parts. However, in recent year, the helium compressor had sometimes stopped by the leakage of seal oil. In 2007, we refurbished the helium compressor with new one. This report describes refurbishment of helium compressor.
Takeuchi, Masaki; Magome, Hirokatsu; Komeda, Masao; Kawasaki, Kozo*
JAEA-Technology 2009-037, 28 Pages, 2010/03
JAEA-Technology-2009-037.pdf:5.71MB
Japan Research Reactor No.3 (JRR-3) has been providing Neutron Transmutation Doping Silicon (NTD-Si). Though the inverse method is employed for producing NTD-Si in JRR-3, it is possible to increase the production rate of NTD-Si by using the neutron filter method. As the result, the prospect that the neutron filter method was able to develop without changing a geometrical size of NTD-Si facility in JRR3 was obtained.
Ota, Kazunori; Ikekame, Yoshinori; Owada, Minoru; Fukushima, Manabu; Oba, Toshinobu; Takeuchi, Masaki; Imahashi, Masaki; Murayama, Yoji
JAEA-Technology 2008-023, 31 Pages, 2008/03
JAEA-Technology-2008-023.pdf:3.3MB
JRR-3 uses shell and tube heat exchangers. The secondary coolant flushes into the tubes and the primary coolant flows outside of the tubes. The heat exchangers are cleaned with the ball-cleaning method, which is a method to clean inside of the tubes by passing the sponge balls with secondary coolant. Decline in the performance of heat exchanger could rise temperature of the primary coolant and then influence the safe and stable reactor operation. The effective way of ball-cleaning for JRR-3 heat exchangers is examined based on past cleaning data. The results show the optimal ball size and the way to determine the cleaning time.
Sono, Hiroki; Tsukamoto, Michio; Aizawa, Eiju; Takeuchi, Masaki; Fukaya, Yuji; Iseda, Hirokatsu*; Ogawa, Kazuhiko; Sakuraba, Koichi; Tonoike, Kotaro
UTNL-R-0446, p.3_1 - 3_10, 2005/03
This report describes an investigation and countermeasures of the unexpected reactor shutdown of the TRACY facility at the Japan Atomic Energy Research Institute on June 17, 2004, caused by a malfunction of a safety rod of the facility. As a result of the investigation, the principal cause of the malfunction was ascribed to a drop in attraction of a binding magnet for the safety rod by a small piece of a foreign material. The following countermeasures were taken against its recurrence: prevention of incidence of foreign materials, reduction of the chance of intrusion of foreign materials into devices, and certain detection of foreign materials. This lesson learned through the experience is expected to be shared with the staffs concerned in reactor operation and maintenance.
Aizawa, Eiju; Ogawa, Kazuhiko; Sakuraba, Koichi; Tsukamoto, Michio; Sugawara, Susumu; Takeuchi, Masaki*; Miyauchi, Masakatsu; Yanagisawa, Hiroshi; Ono, Akio
JAERI-Tech 2002-031, 120 Pages, 2002/03
JAERI-Tech-2002-031.pdf:4.32MB
TRACY (Transient Experiment Critical Facility) in NUCEF (Nuclear Safety Research Facility) is the pulse-type critical facility using uranyl nitrate solution which can carry out various supercritical experiments changing reactivity addition up to 3$.TRACY achieved its first criticality on 20th December 1995,and transient operations have been conducted Since1996.This report summarizes the operation data of 176 experiments from the first criticality to FY2000.
Oba, Toshinobu; Owada, Minoru; Fukushima, Manabu; Takeuchi, Masaki; Uno, Yuki; Murayama, Yoji
no journal, ,
no abstracts in English
Kusunoki, Tsuyoshi; Magome, Hirokatsu; Takeuchi, Masaki; Kobayashi, Shinsho*; Yamashita, Kiyonobu
no journal, ,
JAEA has been conducting practical irradiation for production of Neutron-Transmutation-Doped-Silicon (NTD-Si) since 1977. The JRR-3 and JRR-4 of JAEA are used to irradiate Silicon ingots at present. A Silicon ingot is irradiated with an irradiation facility in the heavy water reflector tank in the JRR-3. The maximum size of silicon ingot which can be irradiated in the facility of JRR-3 is about 152 mm (6 inches) in diameter and 600 mm in length. A silicon ingot is irradiated in the irradiation facility by the side of reactor core in the JRR-4. The maximum silicon ingot which can be irradiated in JRR-4 is about 125 mm (5 inches) in diameter and the 400 mm in length. The amount of NTD-Si was about 3.7 tons at the JRR-3 and about 0.7 tons at the JRR-4 in 2006 Japanese fiscal year. We are planning to investigate the expansion technology of the NTD-Si productivity in the JRR-3.
Araki, Masaaki; Kobayashi, Tetsuya; Oba, Toshinobu; Takeuchi, Masaki
no journal, ,
no abstracts in English
Ishizaki, Katsuhiko; Ota, Kazunori; Takeuchi, Masaki; Imahashi, Masaki; Fukushima, Manabu
no journal, ,
no abstracts in English
