Inspection and repair techniques in reactor vessel of the experimental fast reactor JOYO; Investigation and design for retrieval device of bent MARICO-2 test subassembly

Ashida, Takashi; Miyamoto, Kazuyuki; Okazaki, Yoshihiro*; Ito, Hideaki

JAEA-Technology 2012-047, 106 Pages, 2013/06

JAEA-Technology-2012-047.pdf:11.09MB
JAEA-Technology-2012-047-appendix(CD-ROM).zip:15.46MB

In the experimental fast reactor Joyo, failure of disconnecting the irradiation test subassembly MARICO-2 (Material Testing Irradiation Rig with Temperature Control) was occurred and top of the MARICO-2 test subassembly was bent onto the in-vessel storage rack. As a result of this incident, the operation area of rotating plug for the fuel exchange in Joyo is limited. The replacement of the damaged UCS and retrieving the bent MARICO-2 are required to Joyo restoration. This report describes about investigations and some tests to know the status of MARICO-2 test subassembly and the optimized detail design of retrieval device reflecting those results.

Present status of Japanese tasks for lithium target facility under IFMIF/EVEDA

Nakamura, Kazuyuki; Furukawa, Tomohiro; Hirakawa, Yasushi; Kanemura, Takuji; Kondo, Hiroo; Ida, Mizuho; Niitsuma, Shigeto; Otaka, Masahiko; Watanabe, Kazuyoshi; Horiike, Hiroshi*; et al.

Fusion Engineering and Design, 86(9-11), p.2491 - 2494, 2011/10

https://doi.org/10.1016/j.fusengdes.2011.04.033

In IFMIF/EVEDA, tasks for lithium target system are shared to 5 validation tasks (LF1-5) and a design task (LF6). The purpose of LF1 task is to construct and operate the EVEDA lithium test loop, and JAEA has a main responsibility to the performance of the Li test loop. LF2 is a task for the diagnostics of the Li test loop and IFMIF design. Basic research for the diagnostics equipment has been completed, and the construction for the Li test loop will be finished before March in 2011. LF4 is a task for the purification systems with nitrogen and hydrogen. Basic research for the purification equipment has been completed, and the construction of the nitrogen system for the Li test loop will be finished before March in 2011. LF5 is a task for the remote handling system with the target assembly. JAEA has an idea to use the laser beam for cutting and welding of the lip part of the flanges. LF6 is a task for the design of the IFMIF based on the validation experiments of LF1-5.

Radiation hardening and -embrittlement due to He production in F82H steel irradiated at 250 C in JMTR

Wakai, Eiichi; Jitsukawa, Shiro; Tomita, Hideki*; Furuya, Kazuyuki; Sato, Michitaka*; Oka, Keiichiro*; Tanaka, Teruyuki*; Takada, Fumiki; Yamamoto, Toshio*; Kato, Yoshiaki; et al.

Journal of Nuclear Materials, 343(1-3), p.285 - 296, 2005/08

https://doi.org/10.1016/j.jnucmat.2004.10.167

The dependence of helium production on radiation-hardening and -embrittlement has been examined in a reduced-activation martensitic F82H steel doped with B, B and B+B irradiated at 250C to 2.2 dpa. The total amounts of doping boron were about 60 massppm. The range of He concentration produced in the specimens was from about 5 to about 300 appm. Tensile and fracture toughness tests were performed after neutron irradiation. 50 MeV-He irradiation was also performed to implant about 85 appm He atoms at 120C by AVF cyclotron to 0.03 dpa, and small punch testing was performed to obtain DBTT. Radiation-hardening of the neutron-irradiated specimens increased slightly with increasing He production. The 100 MPam DBTT for the F82H+B, F82H+B+B, and F82H+B were 40, 110, and 155C, respectively. The shifts of DBTT due to He production were evaluated as about 70C by 150 appmHe and 115C by 300 appmHe. The DBTT shift in the small punch testing was evaluated as 50C.

Design and technology development of solid breeder blanket cooled by supercritical water in Japan

Enoeda, Mikio; Kosaku, Yasuo; Hatano, Toshihisa; Kuroda, Toshimasa*; Miki, Nobuharu*; Homma, Takashi; Akiba, Masato; Konishi, Satoshi; Nakamura, Hirofumi; Kawamura, Yoshinori; et al.

Nuclear Fusion, 43(12), p.1837 - 1844, 2003/12

https://doi.org/10.1088/0029-5515/43/12/026

no abstracts in English

Irradiation tests of critical components for remote handling in gamma radiation environment

Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi; Furuya, Kazuyuki; *; Tada, Eisuke; Shibanuma, Kiyoshi; Okawa, Yoshinao; Morita, Yosuke; Yokoo, Noriko*; et al.

JAERI-Tech 94-003, 73 Pages, 1994/08

[This article is unavailable to download the full text due to various reasons.]

Application of extended bias factor method to neutronic characteristics of a sodium-cooled fast breeding reactor core

Kugo, Teruhiko; Mori, Takamasa; Yokoyama, Kenji; Numata, Kazuyuki*; Ishikawa, Makoto; Okajima, Shigeaki

no journal, , 

An extended bias factor method which utilizes a number of experimental results for precision accuracy improvement of neutronic characteristics is applied for a sodium-cooled fast breeding reactor core design. The target neutronic characteristics of a typical 600 MW electric power plant are criticality and sodium void reactivity. With use of integral experimental database of about 200 experimental results, the extended bias factor method eliminates the uncertainty due to cross sections and effectively improves the prediction accuracy.

Technological development of bent test subassembly retrieval device in the experimental fast reactor Joyo

Ashida, Takashi; Okazaki, Yoshihiro; Miyamoto, Kazuyuki; Noguchi, Koichi; Ito, Hideaki

no journal, , 

The 15th periodic inspection of Joyo commenced in May 2007 with the Fuel Handling Machine (FHM) being set up on the Rotating Plug (R/P) for refueling in June. When the R/P was taken down, measuring the load of the Hold-Down Shaft (HDS) revealed an abnormal decrease above the in-vessel storage rack (IVS). As a result of the observations, it was discovered that the top of the irradiation test S/A "MARICO-2"had bent onto the IVS as an obstacle, and had damaged the Upper Core Structure (UCS). The other action items in the restoration work, which are design of UCS and MARICO-2 handling device will be investigated in detail designs. The experience obtained through the restoration work in Joyo will provided valuable insights into possible further improvements and verifications for in-vessel inspection and repair techniques in SFRs.