Research on engineering technology in the full-scale demonstration of EBS and operation technology for HLW disposal; Research report in 2012 (Joint research)

Nakatsuka, Noboru; Sato, Haruo; Tanai, Kenji; Nakayama, Masashi; Sawada, Sumiyuki*; Asano, Hidekazu*; Saito, Masahiko*; Yoshino, Osamu*; Tsukahara, Shigeki*; Hishioka, Sosuke*; et al.

JAEA-Research 2013-034, 70 Pages, 2014/01

JAEA-Research-2013-034.pdf:9.11MB

Japan Atomic Energy Agency (JAEA) and Radioactive Waste Management Funding and Research Center (RWMC) concluded the letter of cooperation agreement on the research and development of radioactive waste disposal in April, 2005, and have been carrying out the collaboration work based on the agreement. JAEA have been carrying out the Horonobe Underground Research Laboratory (URL) Project which is intended for a sedimentary rock in the Horonobe town, Hokkaido, since 2001. In the project, geoscientific research and research and development on geological disposal technology are being promoted. Meanwhile, the government (the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry) has been promoting construction of equipments for the full-scale demonstration of engineered barrier system and operation technology for high-level radioactive waste (HLW) disposal since 2008, to enhance public's understanding to the geological disposal of HLW, e.g. using underground facility. RWMC received an order of the project in fiscal year 2012 (2011/2012) continuing since fiscal year 2008 (2008/2009). Since topics in this project are included in the Horonobe URL Project, JAEA carried out this project as collaboration work continuing in fiscal year 2008. This report summarizes the results of engineering technology carried out in this collaboration work in fiscal year 2012. In fiscal year 2012, part of the equipments for emplacement of buffer material was produced and visualization test for water penetration in buffer material were carried out.

Probing carbon edge exposure of iron phthalocyanine-based oxygen reduction catalysts by soft X-ray absorption spectroscopy

Niwa, Hideharu*; Saito, Makoto*; Kobayashi, Masaki*; Harada, Yoshihisa*; Oshima, Masaharu*; Moriya, Shogo*; Matsubayashi, Katsuyuki*; Nabae, Yuta*; Kuroki, Shigeki*; Ikeda, Takashi; et al.

Journal of Power Sources, 223, p.30 - 35, 2013/02

https://doi.org/10.1016/j.jpowsour.2012.09.031

To design non-platinum, inexpensive, but high performance carbon-based cathode catalysts for polymer electrolyte fuel cells, it is important to elucidate the active site for oxygen reduction reaction (ORR). However, it is difficult to directly identify the active site by applying conventional structural or electronic probes to such complex systems. Here, we used C 1 X-ray absorption spectroscopy (XAS) to observe electronic structure of carbon in iron phthalocyanine-based catalysts, and found a signature of edge exposure below the edge, whose intensity is well correlated with the ORR activity. These results demonstrate that C 1 XAS can be used to characterize the ORR activity of carbon-based cathode catalysts in terms of the edge exposure.

Halo structure of the island of inversion nucleus Ne

Nakamura, Takashi*; Kobayashi, Nobuyuki*; Kondo, Yosuke*; Sato, Yoshiteru*; Aoi, Nori*; Baba, Hidetada*; Deguchi, Shigeki*; Fukuda, Naoki*; Gibelin, J.*; Inabe, Naoto*; et al.

Physical Review Letters, 103(26), p.262501_1 - 262501_4, 2009/12

https://doi.org/10.1103/PhysRevLett.103.262501

no abstracts in English

ZnO as fast scintillators evaluated with Ni-like Ag laser

Furukawa, Yusuke*; Tanaka, Momoko; Murakami, Hidetoshi*; Saito, Shigeki*; Sarukura, Nobuhiko*; Nishikino, Masaharu; Yamatani, Hiroshi; Nishimura, Hiroaki*; Mima, Kunioki*; Kagamitani, Yuji*; et al.

Reza Kenkyu, 36(APLS), p.1028 - 1030, 2008/12

https://doi.org/10.2184/lsj.36.1028

Optical technologies in extreme ultraviolet (EUV) region have been receiving strong interests for the next generation lithography. Here we report properties of ZnO as scintillators in the EUV region, and to demonstrate the feasibility of using a Ni-like Ag EUV laser operated at 13.9-nm to evaluate these properties. The ZnO sample was irradiated with EUV laser pulses and the fluorescence was measured using a streak camera fitted with a spectrograph. A clear, excitonic, fluorescence peak was observed at around 380 nm with a decay lifetime of 3 ns. The prominent peak fluorescence is ideal for EUV detection and further applications including imaging.

Evaluation of fast EUV scintillator using 13.9 nm X-ray laser

Tanaka, Momoko; Furukawa, Hiroyuki*; Murakami, Hidetoshi*; Saito, Shigeki*; Sarukura, Nobuhiko*; Nishikino, Masaharu; Yamatani, Hiroshi; Nagashima, Keisuke; Kagamitani, Yuji*; Ehrentraut, D.*; et al.

Journal of Physics; Conference Series, 112(4), p.042058_1 - 042058_4, 2008/00

https://doi.org/10.1088/1742-6596/112/4/042058

Optical technologies in the extreme ultraviolet (EUV) region have been receiving strong interest for the next generation lithography. Efficient and fast scintillators are one of the key devices functioning in the EUV region. In this paper, we report excellent properties of ZnO and GaN as scintillators in the EUV region, and to demonstrate the feasibility of using a Ni-like Ag EUV laser operated at 13.9-nm to evaluate these properties. The sample was irradiated with EUV laser pulses, and the fluorescence spectrum and the fluorescence lifetime were measured using a streak camera fitted with a spectrograph. In the case of ZnO, a clear, excitonic, fluorescence peak was observed at around 380 nm with a decay lifetime of 3 ns. For GaN, a fluorescence peak at 370 nm having slower 5-ns decay time was observed. In this respect, the EUV scintillation properties of ZnO is said to be more favorable than GaN.

Studies on applications of detectors for marine radioactivity and methodologies for data analysis (Joint Research)

Ito, Toshimichi; Kinoshita, Masataka*; Saito, Saneatsu*; Machiyama, Hideaki*; Shima, Shigeki*; Gasa, Shinichi*; Togawa, Orihiko; Okano, Masaharu*

JAERI-Research 2005-028, 121 Pages, 2005/09

JAERI-Research-2005-028.pdf:12.45MB

no abstracts in English

First operation of circular dichroism measurements with periodic photon-helicity switching by a variably polarizing undulator at BL23SU at SPring-8

Agui, Akane; Yoshigoe, Akitaka; Nakatani, Takeshi*; Matsushita, Tomohiro*; Saito, Yuji; Yokoya, Akinari; Tanaka, Hitoshi*; Miyahara, Yoshikazu*; Shimada, Taihei; Takeuchi, Masao*; et al.

Review of Scientific Instruments, 72(8), p.3191 - 3197, 2001/08

https://doi.org/10.1063/1.1382635

no abstracts in English

Alloying Effects on the Corrosion Behavior of Binary Nb-based and Mo-based Alloys in Liquid Li

Saito, Junichi; Kano, Shigeki; *; Morinaga, Masahiko*

Journal of Nuclear Materials, 264, p.216 - 227, 1999/00

https://doi.org/10.1016/S0022-3115(98)00460-7

None

New approach to the elucidation of corrosion mechanism of ceramics by the ion implantation

Saito, Junichi; Tachi, Yoshiaki; ; Kano, Shigeki

PNC TN9410 98-082, 60 Pages, 1998/08

PNC-TN9410-98-082.pdf:5.96MB

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.

Evaluation of electronic states of implanted materials by molecular orbital calculation

Saito, Junichi; Kano, Shigeki

PNC TN9410 97-073, 69 Pages, 1997/07

PNC-TN9410-97-073.pdf:1.74MB

In order to understand the effect of implanted atom in ceramics and metals on the sodium corrosion, the electronic structures of un-implanted and implanted materials were calculated using DV-X cluster method which was one of molecular orbital calculations. The calculated materials were -SiN, -SiC and -SiC as ceramics, and f.c.c.Fe, b.c.c.Fe and b.c.c. Nb as metals. An Fe, Mo and Hf atom for ceramics, and N atom for metals were selected as implanted atoms. It is known that these metallic elements have exhibited the excellent corrosion resistance against liquid sodium in previous experiments. The summary of results is shown as follows. Energy levels of implanted atom appeared in or near energy band gap in ceramics. The change of ionicities of each element which showed amount of transferred charges and bond order which showed the covalent bond strength between atoms depended on substrates and implanted atoms. The strength of ionic bonding between atoms reduced in -SiN, as ionicities of constituent atom decreased by the implanted atom. The decreases of ionicity depended on implanted atoms and Hf implantation showed the largest decrease in implanted atoms. The bond order in -SiN and -SiC decreased by the implantation. When the implanted atom occupied at substitutional site in -SiC, the ionicities decreased but the bond order increased. Electron state densities of s and p components of implanted N atom appeared lower energy level than that of d component of constituent Fe (or Nb) atoms. The charge transfer took place to N atom from surrounding Fe (or Nb) atoms. Thus the ionicity of N atom was larger than mother metal. The bond order between mother elements reduced by N implantation. In particularly, there were significant decreases of bond order in b.c.c. Fe and b.c.c. Nb. Hence, the bond order in whole cluster decreased largely except for f.c.c. Fe. Consequently, it is ...