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Hirooka, Shun; Nakamichi, Shinya; Matsumoto, Taku; Tsuchimochi, Ryota; Murakami, Tatsutoshi
Frontiers in Nuclear Engineering (Internet), 2, p.1119567_1 - 1119567_7, 2023/03
Storage of plutonium (Pu)-containing materials requires extremely strict attention in terms of physical safety and material accounting. Despite the emphasized importance of storage management, only a few reports are available in the public, e.g., experience in PuO storage in the UK and safety standards in the storage of Pu-containing materials in the US. Japan also stores more U-Pu mixed oxide (MOX) mostly in powder form. Adopting an appropriate storage management is necessary depending on the characteristics of MOX items such as raw powder obtained by reprocessing of spent Light Water Reactor fuels, research and development on the remains of fuel fabrication, which can contain organic materials, and dry-recycled powder during fuel fabrication. Stagnation in fuel fabrications and experience in degradation of MOX containers during extended period of storage have led to the review of the storage method in the Plutonium Fuel Development Center in Japan Atomic Energy Agency. The present work discusses the various nuclear materials, storage methods, experience in degradation of containers that occur during storage, and strategies for future long-term storage.
Wang, Y.*; Tomota, Yo*; Omura, Takahito*; Gong, W.; Harjo, S.
Materialia, 27, p.101685_1 - 101685_9, 2023/03
Im, S.*; Jee, H.*; Suh, H.*; Kanematsu, Manabu*; Morooka, Satoshi; Koyama, Taku*; Nishio, Yuhei*; Machida, Akihiko*; Kim, J.*; Bae, S.*
Journal of the American Ceramic Society, 104(9), p.4803 - 4818, 2021/09
Times Cited Count:8 Percentile:78.06(Materials Science, Ceramics)Irisawa, Keita; Taniguchi, Takumi; Namiki, Masahiro; Garca-Lodeiro, I.*; Osugi, Takeshi; Sakakibara, Tetsuro; Nakazawa, Osamu; Meguro, Yoshihiro; Kinoshita, Hajime*
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 6 Pages, 2017/04
A solidification technique with minimized water content is being developed using phosphate cements for the safe storage of secondary radioactive wastes in the Fukushima Daiichi Nuclear Power Plant. Conventional cement systems become solidified via hydration reactions, and need a certain water content. Phosphate cement systems, however, become solidified via an acid-base reaction, and so they only require water mainly for reasons of workability. A reduced water content of phosphate cement systems is beneficial for the immobilization of the radioactive wastes from mitigating the potential to generate hydrogen gas by the radiolysis of water by radioactive wastes. The current study investigated the water content and mineralogy of calcium aluminate cement (CAC) and phosphate-modified CAC (CAP) cured in open systems at 60, 90 and 120 C and in a closed system at 20
C as a reference case. Water contents in both the CAC and the CAP were seen to decrease as curing progressed. For
90
C, the CAP contained less water than CAC. Free water in CAC converted to structural water by heat treatment, but this was not the case for CAP. An orthophosphate hydrate salt, a precursor phase of hydroxyapatite, was found in CAP when cured at 20 and 60
C, and a mixture of the orthophosphate hydrate salt and hydroxyapatite, Ca
(PO
)
(OH)
, were formed in the CAP when cured at 90
C. Phosphate products in CAP cured at 120
C appears to consist of a different phosphate phase compared with the CAP cured at 20, 60 and 90
C.
Suzuki, Satoshi; Enoeda, Mikio; Hatano, Toshihisa; Hirose, Takanori; Hayashi, Kimio; Tanigawa, Hisashi; Ochiai, Kentaro; Nishitani, Takeo; Tobita, Kenji; Akiba, Masato
Nuclear Fusion, 46(2), p.285 - 290, 2006/02
Times Cited Count:2 Percentile:7.11(Physics, Fluids & Plasmas)This paper presents significant progress in R&D of key technologies on the water-cooled solid breeder blanket for the ITER-TBM in JAERI. By the improvement of heat treatment process for blanket module fabrication, a fine-grained microstructure of F82H, can be obtained by homogenizing it at 1150 C followed by normalizing at 930
C after the HIP process. Moreover, a promising bonding process for a tungsten armor and an F82H structural material was developed by using a uniaxial hot compression without any artificial compliant layer. Also, it has been confirmed that a fatigue lifetime correlation, which was developed for ITER divertor, can be applicable for F82H first wall mock-up. As for R&D on a breeder material, Li
TiO
, the effect of compression loads on thermal conductivity of pebble beds has been clarified. JAERI have extensively developed key technologies for ITER-TBM, and now steps up into an engineering R&D stage, where integrated performance of TBM structures will be demonstrated by scalable mock-ups.
Koppitz, T.*; Jung, P.*; Mller, G.*; Weisenburger, A.*; Futakawa, Masatoshi; Ikeda, Yujiro
Journal of Nuclear Materials, 343(1-3), p.92 - 100, 2005/08
Times Cited Count:7 Percentile:45.17(Materials Science, Multidisciplinary)Cavitation damage of structural materials due to pressure waves is expected to be one of the majior life-time limiting factors in high power liquid metal spallation targets under pulsed operation. Two methods are developed for the European Spallation Source (ESS) to mitigate this damage: Introduction of gas bubbles to surpress the pressure pulse and surface-hardening of structural materials. Surface-hardening of four 8-13%Cr martenstic steels was examined by thermal treatment with pulsed or scanned electron- and laser-beams as well as by nitriding in plasma. A specimens of the 12%Cr steel were tested in liquid mercury under pulsed proton irradiation, and under mechanical pulsed-loading. Surface damage was analysed by optical, confocal-laser, or scanning-electron microscopy, showing in both tests much better resistance of the hardened material compared to standard condition.
Wakai, Eiichi; Taguchi, Tomitsugu; Yamamoto, Toshio*; Tomita, Hideki*; Takada, Fumiki; Jitsukawa, Shiro
Materials Transactions, 46(3), p.481 - 486, 2005/03
Times Cited Count:7 Percentile:51.93(Materials Science, Multidisciplinary)no abstracts in English
Hamada, Kazuya; Nakajima, Hideo; Okuno, Kiyoshi; Endo, Sakaru*; Kikuchi, Kenichi*; Kubo, Yoshio*; Aoki, Nobuo*; Yamada, Yuichi*; Osaki, Osamu*; Sasaki, Takashi*; et al.
JAERI-Tech 2002-027, 23 Pages, 2002/03
The Engineering Design Activities (EDA) for the International Thermonuclear Experimental Reactor (ITER) was performed under the collaboration of Japan, EU, Russia and the US. The EDA was successfully completed in July 2001, in which the development of fabrication technology for advanced components, such as superconducting coils, was conducted. The ITER magnet system consists of Toroidal Field coils, a Central Solenoid (CS), Poloidal Field coils and Correction coils. The construction of these coils requires advanced technologies that fairly exceeded those available at the start of the EDA. Therefore, CS Model Coil and TF Model Coil projects were implemented. To fabricate the CS Model Coil, the fabrication technologies for high performance strand, large cable, winding, heat treatment, joint and insulation are indispensable. This report describes the above detailed fabrication technologies successfully developed in the CS Model Coil Project.
Sugimoto, Makoto; Isono, Takaaki; Koizumi, Norikiyo; Nakajima, Hideo; Kato, Takashi; Hamada, Kazuya; Nunoya, Yoshihiko; Matsui, Kunihiro; Sawada, Kenji*; Takahashi, Yoshikazu; et al.
IEEE Transactions on Applied Superconductivity, 9(2), p.636 - 639, 1999/06
Times Cited Count:1 Percentile:17.18(Engineering, Electrical & Electronic)no abstracts in English
Futakawa, Masatoshi; Steinbrech, R. W.*; Wakui, Takashi*; *
Hyomen Gijutsu, 50(1), p.58 - 62, 1999/00
no abstracts in English
Nakajima, Hideo; Nunoya, Yoshihiko; O.Ivano*; Ando, Toshinari; Kawasaki, T.*; Hanawa, Hiromi*; Seki, Shuichi*; Takano, Katsutoshi*; Tsuji, Hiroshi; *; et al.
Advances in Cryogenic Engineering Materials, Vol.42, p.323 - 330, 1996/00
no abstracts in English
*; *; O.Ivano*; Nunoya, Yoshihiko; Nakajima, Hideo; Tsuji, Hiroshi
Fatigue & Fracture of Engineering Materials & Structures, 18(6), p.671 - 678, 1995/00
Times Cited Count:1 Percentile:19.21(Engineering, Mechanical)no abstracts in English
Hiroki, S.; ; *; ; Murakami, Yoshio
JAERI-M 85-123, 23 Pages, 1985/08
no abstracts in English
*;
JAERI-M 83-086, 103 Pages, 1983/06
no abstracts in English
; Ikawa, Katsuichi; Iwamoto, K.
Journal of Nuclear Materials, 92(2), p.351 - 353, 1980/00
Times Cited Count:21 Percentile:97.17(Materials Science, Multidisciplinary)no abstracts in English
; Takehisa, Masaaki; Machi, Sueo
Reports on Progress in Polymer Physics in Japan, 17, p.217 - 220, 1974/00
no abstracts in English
;
Journal of Nuclear Materials, 45(1), p.82 - 86, 1972/01
Times Cited Count:1no abstracts in English
; ; ;
Journal of Nuclear Science and Technology, 5(12), p.652 - 653, 1968/00
Times Cited Count:14no abstracts in English
Journal of the Physical Society of Japan, 13, P. 614, 1958/00
no abstracts in English