Direct observation of electronic structure change by resistance random access memory effect in amorphous alumina

Kubota, Masato; Nigo, Seisuke*; Kato, Seiichi*; Amemiya, Kenta*

AIP Advances (Internet), 9(9), p.095050_1 - 095050_4, 2019/09

https://doi.org/10.1063/1.5086212

We measured the X-ray absorption spectra of amorphous alumina with vacancy-type oxygen defects which exhibits the resistance random access memory effect. For the first time, we detected changes in the electronic structure owing to the memory effect. A major difference in spectrum was observed near the O K-absorption edge.

Hydrogenation of anodized aluminum and crystal growth of formed hydride at high pressure and high temperature

Saito, Hiroyuki; Kato, Seiichi*; Katagiri, Masahiko*

Materials Transactions, 55(8), p.1114 - 1116, 2014/08

https://doi.org/10.2320/matertrans.MG201411

Three-layer GSO depth-of-interaction detector for high-energy gamma camera

Yamamoto, Seiichi*; Watabe, Hiroshi*; Kawachi, Naoki; Fujimaki, Shu; Kato, Katsuhiko*; Hatazawa, Jun*

Nuclear Instruments and Methods in Physics Research A, 743, p.124 - 129, 2014/04

https://doi.org/10.1016/j.nima.2014.01.011

Conceptual design of multipurpose compact research reactor; Annual report FY2010 (Joint research)

Imaizumi, Tomomi; Miyauchi, Masaru; Ito, Masayasu; Watahiki, Shunsuke; Nagata, Hiroshi; Hanakawa, Hiroki; Naka, Michihiro; Kawamata, Kazuo; Yamaura, Takayuki; Ide, Hiroshi; et al.

JAEA-Technology 2011-031, 123 Pages, 2012/01

JAEA-Technology-2011-031.pdf:16.08MB

The number of research reactors in the world is decreasing because of their aging. However, the planning to introduce the nuclear power plants is increasing in Asian countries. In these Asian countries, the key issue is the human resource development for operation and management of nuclear power plants after constructed them, and also the necessity of research reactor, which is used for lifetime extension of LWRs, progress of the science and technology, expansion of industry use, human resources training and so on, is increasing. From above backgrounds, the Neutron Irradiation and Testing Reactor Center began to discuss basic concept of a multipurpose low-power research reactor for education and training, etc. This design study is expected to contribute not only to design tool improvement and human resources development in the Neutron Irradiation and Testing Reactor Center but also to maintain and upgrade the technology on research reactors in nuclear power-related companies. This report treats the activities of the working group from July 2010 to June 2011 on the multipurpose low-power research reactor in the Neutron Irradiation and Testing Reactor Center and nuclear power-related companies.

Study of ageing effect of long-term storage fuel in prototype fast breeder reactor Monju

Kato, Yuko; Umebayashi, Eiji; Okimoto, Yutaka; Okuda, Eiichi; Takayama, Koichi; Ozawa, Takayuki; Maeda, Seiichiro; Matsuzaki, Masaaki; Yoshida, Eiichi; Maeda, Koji; et al.

JAEA-Research 2007-019, 56 Pages, 2007/03

JAEA-Research-2007-019.pdf:6.79MB

In order to resume the System Startup Test (SST) of Monju, replacement fuel have to be loaded in exchange for some of initial fuel now loaded in the core to compensate core reactivity lost by decay of Pu-241 in them. The replacement fuel were being stored either in sodium in an ex-vessel storage tank or in air in a storage rack for about 10 years since their fabrication. The initial fuel were irradiated during the SST which was suspended in the end of 1995 and then stayed being loaded in the sodium-circulated core. As this long-term storage and loading may deteriorate mechanical integrity of the assemblies, a study has been made thoroughly on its thermal-hydraulic, structural and material effects on them that might be caused by irradiation in the core, sodium and mechanical environment. The study has shown that the mechanical integrity of them is well maintained even with this long-term storage and loading.

Corrosion performance of metal materials in reprocessing solution of spent nuclear fuel

Takeda, Seiichiro; ; ; ; Kato, Toshihiro*; *; Fujisaku, Kazuhiko*

JNC TN8400 2002-007, 135 Pages, 2001/12

JNC-TN8400-2002-007.pdf:9.39MB

Corrosion performance of materials used for nuclear fuel reprocessing plant was studied for the extension of their lifetime during in-service period. Research was performed focusing on characteristics of reprocessing solution which is very important corrosion factor on environmental side. In the first stage, fundamental corrosion behavior of several kinds of candidate materials such as 304ULC, 310Nb, Ti, Ti-5Ta and Zr was investigated in pure nitric acid solution. Then corrosion performance of such materials in reprocessing environment was made cleared by means of so-called hot test which is used actual reprocessing solution under radioactive conditions. The results are summarized as follows. (1) With regards to the effects of uranium and plutonium on corrosion, high valence plutonium (Pu(Ⅵ)) accelerated the corrosion of stainless steels in nitric acid, but uranium did not affect on them. It is caused by trans-passive dissolution based on the shift of corrosion potential to the noble position. It is thought that the potential shift is caused by increase of the cathodic current on the stainless steel surface due to the reduction of Pu(Ⅵ) to Pu(IV). (2) In fission product (FP) elements, ruthenium accelerated the corrosion of stainless steel in nitric acid when its concentration was comparatively high. Other FP's did not affect on them. The corrosion potential of stainless steel shifts toward noble region by adding ruthenium in nitric acid where high corrosion rates are exhibited. It is thought that the potential shift is caused by the enhancement of cathodic reactions on metal surface due to co-existence of ruthenium in nitric acid. (3) Ti, Ti-5Ta and Zr showed excellent corrosion resistance in nitric acid with and without Plutonium and ruthenium. Especially, Ti and Ti-5Ta showed the improvement of corrosion resistance by co-existing Plutonium or ruthenium. It was explained by chemical stability of surface oxide film due to plutonium or ruthenium oxidant.

Development of a 1-kg/s scale supercritical helium pump

Kawano, Katsumi; Kato, Takashi; Hamada, Kazuya; Shimba, Toru*; Tsuji, Hiroshi; *; *; *; *

Proceedings of 17th International Cryogenic Engineering Conference (ICEC17), p.255 - 258, 1998/00

no abstracts in English

None

; Takeda, Seiichiro; Kawata, Tomio; Kato, Toshihiro*; *

PNC TN8410 91-279, 49 Pages, 1991/11

PNC-TN8410-91-279.pdf:6.76MB

no abstracts in English

On the behaviour of radioactive aerosols in the air inside nuclear facilities

*; Iida, Takao*; *; *; Nagai, Hideo*; Kato, Takao*; Kito, Osamu*; Yamamoto, Seiichi*; Yoshida, Mamoru

PNC TJ868 80-01, 71 Pages, 1980/05

PNC-TJ868-80-01.pdf:2.46MB

no abstracts in English

None

*; Ishida, Junichiro; *; *; ; *

PNC TN841 77-45, 42 Pages, 1977/08

PNC-TN841-77-45.pdf:2.48MB

no abstracts in English