Cause investigation for thinning of anchor bolts and gaps between anchor bolt nuts and a flange plate at the JMTR Hot Laboratory exhaust stack

Shibata, Akira; Kitagishi, Shigeru; Watashi, Katsumi; Matsui, Yoshinori; Omi, Masao; Sozawa, Shizuo; Naka, Michihiro

Nihon Hozen Gakkai Dai-13-Kai Gakujutsu Koenkai Yoshishu, p.290 - 297, 2016/07

The exhaust stack of Japan Materials Testing Reactor Hot laboratory is a part of gaseous waste treatment system. It was built in 1970 and is 40 m in height. In 2015, thinning was found at some anchor bolts on base of the stack. When thinning of anchor bolts were investigated, gaps between anchor bolt nuts and flange plate was found. JAEA removed steel cylinder of stack which is 33 m in height for safety. In the end of investigation, thinning was found in all anchor bolts of the stack. Cause investigation for the thinning and the gaps were performed. It is concluded that the thinning was caused by water infiltration over a long period of time and the gaps were caused by elongation of thinning part of anchor bolts by the 2011 earthquake off the Pacific coast of Tohoku.

Plan and reports of coupled irradiation (JRR-3 and JOYO of research reactors) and hot facilities work (WASTEF, JMTR-HL, MMF and FMF); R&D project on irradiation damage management technology for structural materials of long-life nuclear plant

Matsui, Yoshinori; Takahashi, Hiroyuki; Yamamoto, Masaya; Nakata, Masahito; Yoshitake, Tsunemitsu; Abe, Kazuyuki; Yoshikawa, Katsunori; Iwamatsu, Shigemi; Ishikawa, Kazuyoshi; Kikuchi, Taiji; et al.

JAEA-Technology 2009-072, 144 Pages, 2010/03

JAEA-Technology-2009-072.pdf:45.01MB

"R&D Project on Irradiation Damage Management Technology for Structural Materials of Long-life Nuclear Plant" was carried out from FY2006 in a fund of a trust enterprise of the Ministry of Education, Culture, Sports, Science and Technology. The coupled irradiations or single irradiation by JOYO fast reactor and JRR-3 thermal reactor were performed for about two years. The irradiation specimens are very important materials to establish of "Evaluation of Irradiation Damage Indicator" in this research. For the acquisition of the examination specimens irradiated by the JOYO and JRR-3, we summarized about the overall plan, the work process and the results for the study to utilize these reactors and some facilities of hot laboratory (WASTEF, JMTR-HL, MMF and FMF) of the Oarai Research-and-Development Center and the Nuclear Science Research Institute in the Japan Atomic Energy Agency.

Renewal plan of the JMTR Hot Laboratory for the Irradiation test of high burn-up fuels in FY2007

Sozawa, Shizuo; Nakagawa, Tetsuya; Omi, Masao; Hayashi, Koji; Iwamatsu, Shigemi; Kawamata, Kazuo; Kato, Yoshiaki; Kanazawa, Yoshiharu

JAEA-Technology 2009-069, 32 Pages, 2010/03

JAEA-Technology-2009-069.pdf:7.33MB

Refurbishment of the Japan Materials Testing Reactor (JMTR), which is recognized as one of important facilities in Japan for safety research, is in progress by the JAEA. In Extensive safety research of light-water reactor (LWR) fuels and materials under a contract with the Nuclear and Industrial Safety Agency of Ministry of Economy, Trade and Industry of Japan, the irradiation tests are planned in order to examine integrity of the LWR fuels and structure materials. For the irradiation tests of high burnup fuels and irradiated materials in the JMTR, modification of the hot laboratory facilities are needed, which are (1) strengthening JMTR hot-lab. cell-shielding, (2) the capsule assembling device, (3) domestic transportation cask, (4) fuel-rod center-hole processing device, (5) master-slave manipulators, (6) power manipulator, and (7) scanning electron microscope.

Development of welding techniques for assembling of IASCC Test Capsule

Shibata, Akira; Kawamata, Kazuo; Taguchi, Taketoshi; Kaji, Yoshiyuki; Shimizu, Michio*; Kanazawa, Yoshiharu; Matsui, Yoshinori; Iwamatsu, Shigemi; Sozawa, Shizuo; Tayama, Yoshinobu; et al.

JAEA-Technology 2008-029, 40 Pages, 2008/03

JAEA-Technology-2008-029.pdf:25.78MB

Irradiation assisted stress corrosion cracking (IASCC) is considered to be one of the key issues from a viewpoint of the life management of core components in the aged Light Water Reactors. The in-situ crack extension examination and the in-situ constant load tensile test in the reactor are required for the study of IASCC. There are, however, some technical hurdles to be overcome for the experiments. For this in-situ IASCC test, techniques for assembling pre-irradiated specimens into an capsule in a hot cell by remote handling are necessary. In this report, I describe the establishment of those remote assembling techniques and development of new welding apparatus and the TIG upset welding for stainless tube of 3 mm in thickness. Already IASCC capsules having pre-irradiated CT specimens were remotely assembled using these techniques in the hot cell for performing crack growth tests under irradiation in JMTR. And eight in-situ IASCC capsules have been finished successfully in JMTR.

Wave excitation in magnetically confined plasmas with an anisotropic velocity distribution

Ichimura, Makoto*; Higaki, Hiroyuki*; Kakimoto, Shingo*; Yamaguchi, Yusuke*; Nemoto, Kenju*; Katano, Makoto*; Kozawa, Isao*; Muro, Taishi*; Ishikawa, Masao; Moriyama, Shinichi; et al.

Fusion Science and Technology, 51(2T), p.150 - 153, 2007/02

https://doi.org/10.13182/FST07-A1337

In magnetically confined plasmas, fluctuations in the ion cyclotron range of frequency (ICRF) will be driven by the presence of non-thermal ion energy distribution. In strong ICRF heating experiments on the GAMMA 10 tandem mirror, plasmas with a strong temperature anisotropy have been formed. Alfven-ion-cyclotron (AIC) modes are spontaneously excited due to strong temperature anisotropy. High-energy ions are trapped in the local mirror and will form the velocity distribution with the strong anisotropy. To study the relation among the AIC modes, ICEs and beam-driven electrostatic instabilities with non-thermal energy distribution is the main purpose of this work. When the NBs are injected, the magnetic fluctuations due to injected beams and FP ions are detected by ICRF antennas used as pickup loops on JT-60U. The wave excitation near ion cyclotron and its higer harmonic frequencies are studied experimentally and theoretically in plasmas with non-thermal ion energy distribution.

Status of Japanese response to the JCO accident

Nozawa, Masao*; Watanabe, Norio

Proceedings of US-Japan Workshop on the Role of Nuclear Energy in a New Environment of Deregulation and Climate Change, 14 Pages, 2000/10

no abstracts in English

Measurements of beam-foil spectra of highly ionized chlorine ions in the region of 160-260 AA

Sataka, Masao; Ozawa, Kunio*; Kawatsura, Kiyoshi; ; Komaki, Kenichiro*; Naramoto, Hiroshi; ; Nakai, Yota;

Journal of the Physical Society of Japan, 57(10), p.3352 - 3356, 1988/10

https://doi.org/10.1143/JPSJ.57.3352

no abstracts in English

Lattice location of deuterium in Nb-Mo with ion beams

Naramoto, Hiroshi; Kawatsura, Kiyoshi; Sataka, Masao; ; Nakai, Yota; Ozawa, Kunio*; ; Fujino, Yutaka*;

Nuclear Instruments and Methods in Physics Research B, 33, p.595 - 598, 1988/00

https://doi.org/10.1016/0168-583X(88)90638-6

no abstracts in English

None

Yokoyama, Hiroomi*; Kanazawa, Toshio*; Fukuma, Tadashi*; Tamekiyo, Kozo*; Yanagida, Koji*; Furuya, Takashi*; Kono, Hiroshi*; Ito, Keiji*; Shirakura, Takao*; Kashiwara, Shinichiro*; et al.

PNC TN8410 87-086VOL2, 944 Pages, 1986/09

PNC-TN8410-87-086VOL2.pdf:32.16MB

Reference concepts of the JAERI large fast reactor design studies

Nozawa, Masao*; T.IWAKI*; J.TAKAHASHI*; S.TERASAWA*; H.SHIOZUKA*; M.FUJITA*

ANL-7520 PART-II, p.77 - 85, 1968/00

no abstracts in English