Development of training course on non-destructive assay of nuclear material for Asian region, 2; Development of lectures and exercises on gamma-ray measurement

Yamamoto, Masahiko; Kono, Soma; Saegusa, Yu; Kuno, Takehiko; Sekine, Megumi; Inoue, Naoko; Noro, Naoko; Rodriguez, D.; Yamaguchi, Tomoki; Stinett, J.*

Proceedings of INMM & ESARDA Joint Annual Meeting 2023 (Internet), 10 Pages, 2023/05

The gamma-ray measurement part of the Non-Destructive Assay (NDA) course of safeguards and nuclear material accountancy was developed to focus on gamma-ray measurement allotting two days out of five days. The lectures on the basic characteristics and detection methods and mechanism of gamma-ray detectors were provided as e-learnings which were developed. The part for hands-on exercises were implemented in JAEA facility. Participants have set up each gamma-ray detector, and performed measurements of uranium and the other gamma-ray emitting nuclides. Also, uranium-235 enrichment measurements have been performed. In addition, the participants trained with a handheld gamma-ray spectrometer, HM-5, that is popular for IAEA safeguards as the preparation in the measurement exercise of fresh fuel assemblies in JRR-3, a research reactor facility of JAEA. This paper reports on the development, implementation, and feedback from participants on gamma-ray measurement part of the NDA course.

Communication-overlap techniques for improved strong scaling of gyrokinetic Eulerian code beyond 100k cores on the K-computer

Idomura, Yasuhiro; Nakata, Motoki; Yamada, Susumu; Machida, Masahiko; Imamura, Toshiyuki*; Watanabe, Tomohiko*; Nunami, Masanori*; Inoue, Hikaru*; Tsutsumi, Shigenobu*; Miyoshi, Ikuo*; et al.

International Journal of High Performance Computing Applications, 28(1), p.73 - 86, 2014/02

https://doi.org/10.1177/1094342013490973

Support system for training and education of future expert at PIE Hot Laboratories in Oarai JAEA; FEETS

Osaka, Masahiko; Donomae, Takako; Ichikawa, Shoichi; Sasaki, Shinji; Ishimi, Akihiro; Inoue, Toshihiko; Sekio, Yoshihiro; Miwa, Shuhei; Onishi, Takashi; Asaka, Takeo; et al.

Proceedings of 1st Asian Nuclear Fuel Conference (ANFC), 2 Pages, 2012/03

Support system for training and education of future expert in hot laboratories of Oarai-JAEA, named FEETS, is presented. The system has been established based on research results on both characterization of Oarai hot laboratory and user-needs. Various programs under FEETS are also introduced.

Conceptual design and related R&D on ITER mechanical based primary pumping system

Tanzawa, Sadamitsu; Hiroki, Seiji; Abe, Tetsuya; Shimizu, Katsusuke*; Inoue, Masahiko*; Watanabe, Mitsunori*; Iguchi, Masashi*; Sugimoto, Tomoko*; Inohara, Takashi*; Nakamura, Junichi*

JAEA-Technology 2008-076, 99 Pages, 2008/12

JAEA-Technology-2008-076.pdf:35.19MB

The primary vacuum pumping system of the International Thermonuclear Experimental Reactor (ITER) exhausts a helium (He) ash resulting from the DT-burn with excess DT fueling gas, as well as performing a variety of functions such as pump-down, leak testing and wall conditioning. A mechanical based vacuum pumping system has some merits of a continuous pumping, a much lower tritium inventory, a lower operational cost and easy maintenance, comparing with a cryopump system, although demerits of an indispensable magnetic shield and insufficient performance for hydrogen (H) pumping are well recognized. To overcome the demerits, we newly fabricated and tested a helical grooved pump (HGP) unit suitable for H pumping at the ITER divertor pressure of 0.1-10 Pa. Through this R&D, we successfully established many design and manufacturing databases of large HGP units for the lightweight gas pumping. Based on the databases, we conceptually designed the ITER vacuum pumping system mainly comprising the HGP with an optimal pump unit layout and a magnetic shield. We also designed conceptually the reduced cost (RC)-ITER pumping system, where a compound molecular pump combining turbine bladed rotors and helical grooved ones was mainly used. The ITER mechanical based primary pumping system proposed has eventually been a back-up solution, whereas a cryopump based one was formally selected to the ITER for construction.

Si substrate suitable for radiation-resistant space solar cells

Matsuura, Hideharu*; Iwata, Hiroshi*; Kagamihara, So*; Ishihara, Ryohei*; Yoneda, Masahiko*; Imai, Hideaki*; Kikuta, Masanori*; Inoue, Yuki*; Hisamatsu, Tadashi*; Kawakita, Shiro*; et al.

Japanese Journal of Applied Physics, Part 1, 45(4A), p.2648 - 2655, 2006/04

https://doi.org/10.1143/JJAP.45.2648

no abstracts in English

Selection Study of Am-Target Candidates for the Irradiation in Fast Reactors

Osaka, Masahiko; Yoshimochi, Hiroshi; Donomae, Takako; Inoue, Masaki

JNC TN9420 2003-002, 42 Pages, 2003/10

JNC-TN9420-2003-002.pdf:1.49MB

Selection study of Am target candidates for the irradiation in the experimental fast reactor JOYO was performed by the investigation of previously reported studies as a part of JNC-JAERI joint project. Criteria of the selection of inert matrix for the Am target was decided and preliminary selection was carried out on the basis of the investigation results of the present status of development of target and several selection studies in the world. Detailed investigation of the properties such as thermal conductivity, irradiation behavior,fabrication technique on seven pre-selected candidates, specifically ZrO2, Al2O3, MgO, SiC, Si3N4, MgAl2O4 and TiN, was then performed. Five matrices for Am target candidates, ZrO2, MgO, SiC, Si3N4 and TiN,were consequently selected on considering the criteria,in particular, adaptability of the fabrication process were also designed and decided as follows: Dispersed type of Am oxide particle (dia:100/300 micro meter)into MgO (1) Am oxideparticle fabrication by dry route ; i.e. compacting of Am oxide powder, crushing and sieving (2) Mixing of Am oxide particle with MgO particle made by spray dry (3) Pelletizing by uni-axial press and sintering in one atm of inert atmosphere Mixed type of Am oxide (1) Mixing of Am oxide powder with material (SiC, Si3N4 or TiN) powder (2) Pelletizing by uni-axial press and sintering in one atm of inert atmosphere Fabrication test and property measurement will be conducted for the final decision of Am-containing target.

Power-to-melts of uranium-plutonium oxide fuel pins at a beginning-of-life condition in the experimental fast reactor JOYO

Inoue, Masaki; ; ; ; Sekine, Takashi; Osaka, Masahiko

Journal of Nuclear Materials, 323(1), p.108 - 122, 2002/00

https://doi.org/10.1016/j.jnucmat.2003.08.030

None

Development of a compact W-shaped pumped divertor in JT-60U

Sakurai, Shinji; Hosogane, Nobuyuki; Masaki, Kei; ; ; *; *; Shimizu, Katsuhiro; Akino, Noboru; Miyo, Yasuhiko; et al.

Fusion Engineering and Design, 39-40, p.371 - 376, 1998/00

https://doi.org/10.1016/S0920-3796(97)00176-2

no abstracts in English

Design and evaluation of super-heat-resisting Nb-based and Mo-based alloys

Morinaga, Masahiko*; *; *; *; Inoue, Satoshi*

PNC TJ9603 96-001, 79 Pages, 1996/03

PNC-TJ9603-96-001.pdf:3.48MB

[PURPOSE] In order to develop the frontier domain of technique for the high temperature liquid alkali metal, candidate Nb-based and Mo-based alloys are needed. They are needed to have excellent compatibility with liquid Li (max. 1200C) and super-heat-resistance. In this study, alloy design using a d-electrons alloy theory and estimation of designed alloy were performed. [EXPERIMENTAL METHODS] (1)Workability : A bend test was carried out with the provisionally designed Mo-based alloys, but by modifying the compositions by adding intergranular strengthening elements, Ti, B, C, Hf, into them to improve the ductility. (2)Corrosion resistance to liquid Li : The provisionally desingned Nb-based alloys were immersed in liquid Li at 1200C for three hundred hours, and the weight change due to the corrosion was measured. The corrosion surface was also analyzed using SEM and EPMA. In addition, a similar corrosion test was carried out with binary Nb-based and Mo-based alloys. (3)Embrittlement at 800C : A series of experiments such as the hardness test, X-ray analysis and microstructure observation was perfomed with the Nb-1Zr alloy which was creep-tested at 800C or 1200C. Also, a Nb-1Zr alloy specimen which was not creep-tested, was used as a reference specimen. [RESULTS AND DISCUSSIONS] (1)Workability : The Ti addition into the Mo-based alloys was effective in improving workability. The brittleness of Mo may be caused by the existence of oxygen in the grain boundaries, so that the formation of Ti oxides probably weakened the oxygen effect, resulting in the better workability of the alloy. However, B, C and Hf additions into Mo-based alloys never improved the workability. (2)Corrosion resistance to liquid Li : Many cracks were observed on the corroded surface of the provisionally designed Nb-based alloys despite the addition of a corrosion resistant element, Hf, into them. In paticular, such cracks were developed ...

Electrical insulation and conduction coating for fusion experimental devices

Onozuka, Masanori*; Tsujimura, Seiji*; Toyoda, Masahiko*; Inoue, Masahiko*; Abe, Tetsuya; Murakami, Yoshio

Fusion Technology, 29(1), p.73 - 82, 1996/01

https://doi.org/10.13182/FST96-A30657

no abstracts in English