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Ishii, Katsunori; Morita, Keisuke; Noguchi, Hiroki; Aoki, Takeshi; Mizuta, Naoki; Hasegawa, Takeshi; Nagatsuka, Kentaro; Nomoto, Yasunobu; Shimizu, Atsushi; Iigaki, Kazuhiko; et al.
Dai-27-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (Internet), 4 Pages, 2023/09
Kubo, Shinji
Suiso Enerugi Shisutemu, 48(2), p.126 - 132, 2023/06
no abstracts in English
Yamashita, Shinichiro
Nihon Genshiryoku Gakkai-Shi ATOMO
, 65(4), p.233 - 237, 2023/04
In the wake of the accident at the Fukushima Daiichi Nuclear Power Plant (NPP) of TEPCO due to the Great East Japan Earthquake in 2011, interest in the early implementation of accident tolerant fuel (ATF) not only for many existing NPPs but also for future NPPs, which is expected to dramatically improve the safety of light water reactors, has increased globally, and research and development is currently underway in many countries around the world. In this article, an overview of domestic ATF technology development that has been carried out with the support of the Ministry of Economy, Trade and Industry since 2015, will be introduced.
O vapor on GaN surfacesSumiya, Masatomo*; Sumita, Masato*; Tsuda, Yasutaka; Sakamoto, Tetsuya; Sang, L.*; Harada, Yoshitomo*; Yoshigoe, Akitaka
Science and Technology of Advanced Materials, 23(1), p.189 - 198, 2022/00
Times Cited Count：4 Percentile：51.62(Materials Science, Multidisciplinary)GaN is an attracting material for power-electronic devices. Understanding the oxidation at GaN surface is important for improving metal-oxide-semiconductor (MOS) devices. In this study, the oxidation at GaN surfaces depending on the GaN crystal planes (+c, -c, and m-plane) was investigated by real time XPS and DFT-MD simulation. We found that HO vapor has the highest reactivity due to the spin interaction between HO and GaN surfaces. The bond length between the Ga and N on the -c GaN surface was increased by OH attacking the back side of three-fold Ga atom. The chemisorption on the m-plane was dominant. The intense reactions of oxidation and Al
Ga
N formation for p-GaN were observed at the interface of the AlO
layer deposited by ALD using HO vapor. This study suggests that an oxidant gas other than HO and O should be used to avoid unintentional oxidation during AlGaN atomi layer deposition.
Sato, Shin*; Ono, Hirokazu; Tanai, Kenji; Yamamoto, Shuichi*; Fukaya, Masaaki*; Shimura, Tomoyuki*; Niunoya, Sumio*
Jiban Kogaku Janaru (Internet), 15(3), p.529 - 541, 2020/09
no abstracts in English
Hidaka, Akihide; Himi, Masashi*; Addad, Y.*
Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR 2019) (Internet), 4 Pages, 2019/05
no abstracts in English
Usami, Tsutomu; Moriyama, Kiyofumi; Nishikizawa, Tomotoshi; Nakamura, Hideo
JAERI-Tech 2005-028, 37 Pages, 2005/05
JAERI-Tech-2005-028.pdf:16.32MB
The steam explosion during a severe accident in a light water reactor, which may occur by the contact of molten core and coolant, has been known as a potential threat on the integrity of the containment vessel, and has been studied in the nuclear safety research field. Prediction of the intensity of steam explosions needs an understanding of the initial premixture. However, visual observation of the premixture in experiments is usually difficult due to the vapor generation. Thus, we investigated the possibility of a high-speed X-ray visualization with a 4500 f/s high speed video camera with an image-intensifier and three kinds of scintillator materials: CdWO
, ZnS(Ag) and CsI(Tl). A modeled premixture consisted of metal objects and bubbles in a water vessel was used. The test result showed that the CsI(Tl) scintillator gave the best image quality among the three and the high-speed visualization at 4500 f/s was possible, though in the still picture which carried out one of the recorded picture, the picture became indistinct.
Department of HTTR Project; Department of Advanced Nuclear Heat Technology
JAERI-Review 2004-026, 206 Pages, 2004/12
JAERI-Review-2004-026.pdf:14.16MB
no abstracts in English
Shiina, Yasuaki; Takizuka, Takakazu; Kasahara, Seiji
Nihon Genshiryoku Gakkai-Shi, 46(12), p.862 - 863, 2004/12
no abstracts in English
Shiina, Yasuaki; Nishihara, Tetsuo
JAERI-Tech 2004-057, 51 Pages, 2004/09
JAERI-Tech-2004-057.pdf:2.15MB
no abstracts in English
Munakata, Kenzo*; Kawamura, Hiroshi; Uchida, Munenori*
Journal of Nuclear Materials, 329-333(Part2), p.1357 - 1360, 2004/08
Times Cited Count：14 Percentile：63.95(Materials Science, Multidisciplinary)no abstracts in English
Munakata, Kenzo*; Kawamura, Hiroshi; Uchida, Munenori*
JAERI-Conf 2004-006, p.210 - 215, 2004/03
no abstracts in English
Kawamura, Yoshinori; Konishi, Satoshi; Nishi, Masataka
Fusion Science and Technology, 45(1), p.33 - 40, 2004/01
Times Cited Count：25 Percentile：81.94(Nuclear Science & Technology)Aiming at realization of the efficient blanket tritium recovery system of a fusion reactor, research and development of the hydrogen pump using the proton conductor are furthered. One of the advantages of the system using the hydrogen pump is concurrent processing of hydrogen isotopes and water vapor by one component. In this work, experimental research on the hydrogen extraction characteristic in a water molecule was performed with the hydrogen pump using SrCe
Yb
O
. In hydrogen extraction from a water molecule, application of the threshold, voltage corresponding to the decomposition energy of water, is necessary. The observed threshold was about 500-600mV at 873K and decreased with the increase in water vapor pressure. About pumping of H-HO mixture gas, the permeation of H anteceded water decomposition, and the threshold of water decomposition increased with the increase in hydrogen partial pressure. In order to process concurrently, application of fairly higher voltage is expected to be necessary.
Nishihara, Tetsuo
Bunkyo Nyusu, 2 Pages, 2003/11
no abstracts in English
Shiina, Yasuaki; Sakuragi, Yoichi*; Nishihara, Tetsuo
JAERI-Tech 2003-076, 52 Pages, 2003/09
JAERI-Tech-2003-076.pdf:2.72MB
no abstracts in English
Shiozawa, Shusaku; Ogawa, Masuro; Inagaki, Yoshiyuki; Onuki, Kaoru; Takeda, Tetsuaki
Proceedings of 18th KAIF-KNS Annual Conference, p.209 - 218, 2003/04
no abstracts in English
Hatano, Toshihisa
Meintenansu, 235(1), p.81 - 83, 2003/01
no abstracts in English
Kobayashi, Kazuhiro; Hayashi, Takumi; Iwai, Yasunori; Asanuma, Noriko; Nishi, Masataka
Fusion Science and Technology, 41(3), p.673 - 677, 2002/05
no abstracts in English
Yoshikawa, Masahito; Sato, Mirei; Oshima, Takeshi; Ito, Hisayoshi
Materials Science Forum, 389-393, p.1009 - 1012, 2002/05
no abstracts in English
Takeda, Tetsuaki
Nihon Kikai Gakkai Dai-8-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.199 - 202, 2002/00
There are several methods for enhancement of heat transfer such as attaching various type fins on a channel surface of a heat exchanger tube and a steam reforming tube. The objective of this study is to clarify characteristics of heat transfer and pressure drop in the channel inserted metallic wire with high porosity. A heat transfer experiment was performed using a horizontal circular tube to obtain the heat transfer characteristics of the channel inserted copper wire. From the results obtained in this experiment, it seems to be probable that an enhancement of heat transfer method using metallic wire inserts is further improved under the high temperature conditions in efficiency as compared with the other methods.
