Development of inspection and repair techniques in reactor vessel of the experimental fast reactor "Joyo" and of visual inspection device to observe in-vessel structures

Saito, Takakazu; Imaizumi, Kazuyuki; Oka, Kiyoshi; Aizawa, Hideyuki*; Katagiri, Genichi*

FAPIG, (179), p.3 - 9, 2009/07

The experimental fast reactor Joyo is the first sodium cooled fast reactor in Japan. In-vessel visual inspections have been conducted with an obstacle on the in-vessel storage rack in Joyo. Because of the high radiation dose in the reactor vessel, radiation-resistant fiberscope was applied to Joyo. The radiation-resistant fiberscope was inserted into the reactor vessel thorough the inspection hole and fuel handling hole on rotating plugs. In order to observe the top of the subassemblies and in-vessel storage rack, an I-shape device which had a downward and side view monitoring radiation-resistant fiberscopes was used. To observe the bottom face of the upper core structure, a remote handling visual device whose tip could bend into an L-shape was developed to insert the radiation-resistant fiberscope into the 70 mm gap between the bottom of the upper core structure and the top of the subassemblies. The observations of the top of the subassemblies and in-vessel storage rack were conducted from October 2007 to February 2008. The bottom face of the upper core structure was observed in July 2008. The number of photographs of the entire bottom face of the upper core structure reached approximately 35,000. Confirmation was made that the remote handling device equipped with the radiation-resistant fiberscope would achieve the expected performance. These observations results provided useful information on incident investigations. In addition, fundamental findings and the experience gained during this study, which included the design of equipment, operating procedures, resolution, lighting adjustments, photograph composition and the durability of the radiation-resistant fiberscope under radiation exposure, provided valuable insights into possible further improvements and verifications for in-vessel visual observation techniques in an sodium fast reactor.

Remote handling design for moderator-reflector maintenance in JSNS

Teshigawara, Makoto; Aizawa, Hideyuki; Harada, Masahide; Kinoshita, Hidetaka; Meigo, Shinichiro; Maekawa, Fujio; Kaminaga, Masanori; Kato, Takashi; Ikeda, Yujiro

JAERI-Tech 2005-029, 24 Pages, 2005/05

JAERI-Tech-2005-029.pdf:3.38MB

This report introduces the present design status of remote-handling devices for activated and used components such as moderator and reflector in a spallation neutron source of the Material and Life Science Facility (MLF) at J-PARC. The design concept and maintenance scenario are also mentioned. A key maintenance scenario adopts that the used components should be taken out from the MLF to the other storage facility after the volume reduction of them. Almost full remote handling is available to the maintenance work except for the connection/disconnection pipes of the cooling water. Total six remote handling devices are used for moderator-reflector maintenance. They are also available to the proton beam window and muon target maintenance. Maintenance scenario is separated into two works. One is to replace used components to new ones during beam-stop and the other is dispose used components during beam operation. Required period of replacement work is estimated to be 15 days, on the other hand, the disposal work is 26 days after dry up work (30 days), respectively.

Advanced loop type sodium-cooled fast reactor

Aizawa, Kosuke; Ando, Masato; Kotake, Shoji; Hayashi, Hideyuki; Hayafune, Hiroki; Fujii, Tadashi; Sato, Ikken; Kaito, Takeji

no journal, , 

no abstracts in English

Completion of J-PARC 1 MW pulsed spallation neutron source facility, 4; Remote handling facility for target

Kinoshita, Hidetaka; Aizawa, Hideyuki; Kawasaki, Susumu; Ueda, Kazuaki; Takagiwa, Katsunori; Ito, Manabu; Kaminaga, Masanori; Kato, Takashi

no journal, , 

Construction of J-PARC pulsed spallation neutron source was completed. Main components of the spallation neutron source, as the mercury target container, reflector, moderators, proton beam window and etc, are damaged by irradiation of proton and/or neutron. Therefore, each component has to be replaced periodically. All these components must be replaced by remote handling, because of the high activation by proton beam and neutron irradiation. Remote handling facility for the neutron source components consists of handling device for the targetas the power manipulator, the target replacement truck for the target container replacement and other facilities for maintenance or replacement work, and the storage facility for cool down of the radioactivity in spent components including some kinds of rack for temporary storage and the cutting device for reducing volume. In this presentaion, it is repoted that the design and testresult of remote handling facility.

Inspection and repair techniques in reactor vessel of sodium cooled fast reactor, 2-2; Development of visual inspection device to observe in-vessel structures

Imaizumi, Kazuyuki; Tobita, Shigeharu; Saito, Takakazu; Katagiri, Genichi*; Aizawa, Hideyuki*; Yaginuma, Yoshihiro*

no journal, , 

no abstracts in English

Activity of the MLF radiation safety team in FY2018

Harada, Masahide; Kawakami, Kazuhiro*; Aizawa, Kazuya; Soyama, Kazuhiko; Ishikado, Motoyuki*; Hiramatsu, Hideyuki*; Hashimoto, Norimichi*; Hosoya, Tomonori*; Ichimura, Katsuhiro*

no journal, , 

no abstracts in English