Naruto, Kenichi*; Nishino, Hiroyuki; Kurisaka, Kenichi; Yamano, Hidemasa; Okano, Yasushi; Okamura, Shigeki*; Eto, Masao*
Proceedings of 9th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-9) (CD-ROM), 10 Pages, 2014/11
Suzuki, Yoshiyuki*; Yamaguchi, Mitsutaka; Odaka, Hirokazu*; Shimada, Hirofumi*; Yoshida, Yukari*; Torikai, Kota*; Sato, Takahiro; Arakawa, Kazuo*; Kawachi, Naoki; Watanabe, Shigeki; et al.
Radiology, 267(3), p.941 - 947, 2013/06
Saegusa, Jun; Kurikami, Hiroshi; Yasuda, Ryo; Kurihara, Kazuo; Arai, Shigeki; Kuroki, Ryota; Matsuhashi, Shimpei; Ozawa, Takashi; Goto, Hiroaki; Takano, Takao; et al.
Health Physics, 104(3), p.243 - 250, 2013/03
After the Nuclear accident on March 2011, water discharge from many outdoor swimming pools in the Fukushima prefecture was suspended out of concern that radiocesium in the pool water would flow into farmlands. We have reviewed the existing flocculation method for decontaminating pool water and established a practical decontamination method by demonstrating the process at several pools in the Fukushima prefecture.
Chimi, Yasuhiro; Shibata, Akira; Ise, Hideo; Kasahara, Shigeki; Kawaguchi, Yoshihiko*; Nakano, Junichi; Omi, Masao; Nishiyama, Yutaka
Proceedings of Enlarged Halden Programme Group Meeting 2011 (CD-ROM), 10 Pages, 2011/10
In order to load a large specimen of 0.5T-CT up to a high stress intensity factor of 30 MPa, we have adopted a lever type loading unit for in-pile irradiation-assisted stress corrosion crack (IASCC) growth tests in the Japan Materials Testing Reactor (JMTR). In this unit, the applied load is generated by shrinking a bellows with lower inner gas pressure than surrounding water pressure and enlarged by leverage. The crack length of the specimen is monitored by potential drop method (PDM) using mineral insulator (MI) cables. In this paper, technical concerns of the in-pile crack growth test unit, especially the estimation procedure of applied load to the specimen inside the irradiation capsule and the evaluation of precision of the PDM signals are presented.
Chimi, Yasuhiro; Kasahara, Shigeki; Ise, Hideo; Kawaguchi, Yoshihiko*; Nakano, Junichi; Nishiyama, Yutaka
Proceedings of 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors (CD-ROM), p.1219 - 1228, 2011/08
The Japan Atomic Energy Agency (JAEA) has a plan of irradiation tests using the Japan Materials Testing Reactor (JMTR), in order to evaluate the effects of change in material properties and water chemistry caused by the neutron/-ray irradiation on stress corrosion crack (SCC) growth of stainless steels from the view points of the integrity of reactor core internals for boiling water reactors (BWRs). The difference of SCC growth and its electrochemical corrosion potential (ECP) dependence between in-pile and out-of-pile tests is not fully understood because of a few in-pile data which is comparable with out-of-pile database. This paper presents a systematic review on SCC growth data of irradiated stainless steels and the outline of the in-pile test plan for crack growth of irradiated SUS316L stainless steel under simulated BWR conditions in the JMTR, together with the development of the in-pile test techniques.
Yotoriyama, Mamoru*; Takano, Junichi*; Namai, Kiyoshi*; Yoshihara, Ryohei; Nozawa, Shigeki; Hase, Yoshihiro; Narumi, Issei
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 71, 2011/01
no abstracts in English
Togashi, Tadashi*; Takahashi, Eiji*; Midorikawa, Katsumi*; Aoyama, Makoto; Yamakawa, Koichi; Sato, Takahiro*; Iwasaki, Atsushi*; Owada, Shigeki*; Okino, Tomoya*; Yamanouchi, Kaoru*; et al.
Optics Express (Internet), 19(1), p.317 - 324, 2011/01
The 13th harmonic of a Ti:sapphire (Ti:S) laser in the plateau region was injected as a seeding source to a 250-MeV free-electron-laser (FEL) amplifier. When the amplification conditions were fulfilled, strong enhancement of the radiation intensity by a factor of 650 was observed. The random and uncontrollable spikes, which appeared in the spectra of the Self-Amplified Spontaneous Emission (SASE) based FEL radiation without the seeding source, were found to be suppressed drastically to form to a narrow-band, single peak profile at 61.2 nm. The properties of the seeded FEL radiation were well reproduced by numerical simulations. We discuss the future precept of the seeded FEL scheme to the shorter wavelength region.
Kobayashi, Nobuo*; Kano, Sayaka*; Sasaki, Shinichiro*; Tasaki, Keisuke*; Nakatsuka, Akira*; Nozawa, Shigeki; Hase, Yoshihiro; Narumi, Issei
JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 77, 2009/12
Adachi, Motoyasu; Ohara, Takashi; Kurihara, Kazuo; Tamada, Taro; Honjo, Eijiro; Okazaki, Nobuo; Arai, Shigeki; Shoyama, Yoshinari; Kimura, Kaname*; Matsumura, Hiroyoshi*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 106(12), p.4641 - 4646, 2009/03
To further understand the catalytic mechanism and inhibitor recognition of HIV-1 protease, we need to determine the locations of key hydrogen atoms in the catalytic aspartates Asp25 and Asp125. The structure of HIV-1 protease in complex with transition-state analog KNI-272 was determined by combined neutron crystallography at 1.9 resolution and X-ray crystallography at 1.4 resolution. The resulting structural data shows that the catalytic residue Asp25 is protonated and that Asp125 is deprotonated. The proton on Asp25 makes a hydrogen bond with the carbonyl group of the allophenylnorstatine group in KNI-272. The deprotonated Asp125 bonds to the hydroxyl proton of Apns. The results provide direct experimental evidence for proposed aspects of the catalytic mechanism of HIV-1 protease; and can therefore contribute substantially to the development of specific inhibitors for therapeutic application.
Kawachi, Naoki; Watanabe, Shigeki; Sato, Takahiro; Arakawa, Kazuo; Takeda, Shinichiro*; Ishikawa, Shinnosuke*; Aono, Hiroyuki*; Watanabe, Shin*; Yamaguchi, Mitsutaka*; Takahashi, Tadayuki*; et al.
2008 IEEE Nuclear Science Symposium Conference Record (CD-ROM), p.1540 - 1543, 2008/10
Kasai, Satoshi*; Kamiya, Kensaku; Shinohara, Koji; Kawashima, Hisato; Ogawa, Hiroaki; Uehara, Kazuya; Miura, Yukitoshi; Okano, Fuminori; Suzuki, Sadaaki; Hoshino, Katsumichi; et al.
Fusion Science and Technology, 49(2), p.225 - 240, 2006/02
The diagnostic system of JFT-2M has consisted of about 30 individual diagnostic instruments,which were used to study the plasma production, control, equilibrium, stability, confinement, plasma heating by NBI and/or RF (LH, ICRF, ECH) and current drive by RF. In these instruments, the motional Stark effect (MSE) polarimeter, charge exchanged recombination spectroscopy (CXRS), heavy-ion beam probe (HIBP), time of flight (TOF) neutral particle analyzer, etc. have contributed to make clear the improved mechanism of confinement such as H-mode and High Recycling Steady (HRS) H-mode, and to search the operational region of these modes.The infrared TV camera system and lost ion probe have played a very important role to investigate the heat load onto the walls due to ripple loss particles and escaping ions from core plasma, respectively.
Ito, Toshimichi; Kinoshita, Masataka*; Saito, Saneatsu*; Machiyama, Hideaki*; Shima, Shigeki*; Gasa, Shinichi*; Togawa, Orihiko; Okano, Masaharu*
JAERI-Research 2005-028, 121 Pages, 2005/09
no abstracts in English
; Kano, Shigeki; Tachi, Yoshiaki; *
JNC TN9410 2000-013, 89 Pages, 2000/09
Lithium is one of goodcoolants because of high boiling point (1317C), small specific gravity (0.47 at 600C) and large specific heat (1cal/g/C). Therefore if lithium will be used in fast reactor for coolant, the heat efficiency of reactor will largely increase. Here the fundamental properties of lithium and the results of examination on chemical reaction, combustion and extinction are shown. These examinations were also carried out on sodium to compare with lithium. The differences between both are that lithium reacts more moderately with water, not explosive, and is not combustible but after ignition burns at higher temperature and longer.
Tachi, Yoshiaki; Kano, Shigeki; *; *
Journal of Nuclear Materials, 271-272, p.486 - 490, 1999/05
Kaji, Yoshiyuki; Tsuji, Hirokazu; Sakino, Takao*; Fujita, Mitsutane*; Kinugawa, Junichi*; Tachi, Yoshiaki*; Saito, Junichi*; Kano, Shigeki*; Shimura, Kazuki*; Nakajima, Ritsuko*; et al.
JAERI-Tech 99-007, 32 Pages, 1999/02
no abstracts in English
Tsuji, Hirokazu; ; Fujita, Mitsutane*; Kano, Shigeki*; Tachi, Yoshiaki*; Shimura, Kazuki*; Nakajima, Ritsuko*; Iwata, Shuichi*
Advances in Science and Technology, 24, p.417 - 424, 1999/00
no abstracts in English
Tsuji, Hirokazu; ; Fujita, Mitsutane*; Kurihara, Yutaka*; Kano, Shigeki*; Tachi, Yoshiaki*; Shimura, Kazuki*; Nakajima, Ritsuko*; Iwata, Shuichi*
Journal of Nuclear Materials, 271-272, p.486 - 490, 1999/00
no abstracts in English
Saito, Junichi; Kano, Shigeki; *; Morinaga, Masahiko*
Journal of Nuclear Materials, 264, p.216 - 227, 1999/00
Saito, Junichi; Kano, Shigeki; *; Kudo, Hisaaki*
JAERI-Review 98-016, p.164 - 166, 1998/10
Saito, Junichi; Tachi, Yoshiaki; ; Kano, Shigeki
PNC TN9410 98-082, 60 Pages, 1998/08
Ceramics possessing high temperature strength are promising matelials for the structural application in severe environment. The development of ceramics has been carried out in order to use them in FBR environment such as liquid sodium. In particular, corrosion behavior of ceramics has been investigated to improve the corrosion resistance in liquid sodium. However, the corrosion mechanism of ceramics was not comprehended in detail even now. Because corrosion products which were deposited on the surface of test pieces a during corrosion test and played an important role in corrosion behavior were not detected distinctly after the corrosion test. In this study, an ion implantation technique was applied to understand the corrosion mechanism of ceramics in the stead of the conventional corrosion test. Sodium ions were implanted in ceramics (100keV, 1.910ions/cm) and then heat treatment was performed at either 923K or 823K for 36ks in argon atmosphere. After that, products on the surface were analyzed using SEM and TEM observation and X-ray diffraction. Consequently, a kind of the corrosion product was not identified exactly, but the presence of corrosion products was confirmed on the surface. It caused by the amount of corrosion products was only a few. In future, it is necessary to carry systematically out the implantation and heat treatment under various conditions. Therefore, it seems that the beneficial information will be obtained to understand the corrosion mechanism of ceramics.