Reformation of protective oxide layers on artificially abraded surfaces of FeCrAl alloy during 40000h exposure in flowing lead-bismuth eutectic

Kondo, Masatoshi*; Kitamura, Yoshiki*; Kawarai, Atsushi*; Saito, Shigeru; Obayashi, Hironari

Corrosion Science, 262, p.113646_1 - 113646_14, 2026/04

https://doi.org/10.1016/j.corsci.2026.113646

The corrosion resistance of FeCrAl alloy APMT (Fe-21Cr-5Al-3Mo) in flowing lead-bismuth eutectic (LBE) was investigated by corrosion tests performed at 723 K using a non-isothermal forced convection loop. The oxygen concentration in flowing LBE was controlled at 110 wt%. No severe corrosion or erosion was detected on the specimens exposed to flowing LBE for 2000 h and 4000 h. Multiple oxide layers consisting of Fe-rich, Cr-rich and Al-rich sub-layers were formed in situ on the surface of APMT during the corrosion tests, which effectively suppressed corrosion and erosion. The oxide layers were intentionally removed by gentle abrasion prior to re-immersion and the specimens were then re-immersed in flowing LBE for an additional 2000 h. The oxide layers were spontaneously re-formed in situ on the abraded surface. This behavior indicates a self-healing capability. The results of micro-scratch tests indicated that the in-situ formed multiple oxide layers exhibited high adhesion strength in the shear direction after the 2000 h corrosion test.

Application of indentation technique to material degradation evaluation in the mercury target vessel for spallation neutron sources

Wakui, Takashi; Saito, Shigeru; Futakawa, Masatoshi

Jikken Rikigaku, 24(4), p.212 - 218, 2024/12

Irradiation damage is one of the main factors determining the lifetime of the mercury target vessel for spallation neutron source in J-PARC. To understand material degradation of the used vessels, it is planned to conduct an evaluation using inverse analyses with indentation tests on the structural materials of the used vessels and numerical experiments. This evaluation technique was applied to two kinds of ion-irradiated materials with different displacement damage doses, in which the irradiation condition was simulated. It could be confirmed that the ultimate strength increased, and the total elongation decreased with increasing irradiation. These trends are like the material degradation behaviors which have been reported by using small specimen's tensile tests.

Sodium-cooled Fast Reactors

Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.

Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07

https://shop.elsevier.com/books/sodium-cooled-fast-reactors/morishita/978-0-12-824076-2

This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.

Silicon avalanche photodiode linear-array detector with multichannel scaling system for pulsed synchrotron X-ray experiments

Kishimoto, Shunji*; Mitsui, Takaya; Haruki, Rie*; Yoda, Yoshitaka*; Taniguchi, Takashi*; Shimazaki, Shoichi*; Ikeno, Masahiro*; Saito, Masatoshi*; Tanaka, Manobu*

Journal of Instrumentation (Internet), 10(5), p.C05030_1 - C05030_6, 2015/05

https://doi.org/10.1088/1748-0221/10/05/C05030

Nitrogen K-edge X-ray absorption near edge structure (XANES) spectra of purine-containing nucleotides in aqueous solution

Shimada, Hiroyuki*; Fukao, Taishi*; Minami, Hirotake*; Ukai, Masatoshi*; Fujii, Kentaro; Yokoya, Akinari; Fukuda, Yoshihiro*; Saito, Yuji

Journal of Chemical Physics, 141(5), p.055102_1 - 055102_8, 2014/08

https://doi.org/10.1063/1.4891480

Visualization of blurry images of liquid by multi-scale analysis

Miyamura, Hiroko; Kureta, Masatoshi; Segawa, Mariko; Kubo, Jun*; Saito, Takafumi*; Suzuki, Yoshio; Takemiya, Hiroshi

Visualization of Mechanical Processes (Internet), 1(3), 8 Pages, 2011/10

https://doi.org/10.1615/VisMechProc.v1.i3.90

The use of high frame rate neutron radiography has been proposed as a method for recording images of oil in a running car engine. However, it is difficult to capture the behavior of oil from such images, because the images are dark and blurry. Therefore, we attempt to overcome this problem using a multi-scale image processing technique, in which the oil regions are classified based on scale. This method can be used to focus attention on objects with a particular scale. In addition, we propose a technique by which to capture the time-dependent behavior of oil using spatio-temporal image analysis. Using these techniques, the region of interest can be determined and observed carefully.

X-ray absorption spectra of nucleotides (AMP, GMP, and CMP) in liquid water solutions near the nitrogen K-edge

Ukai, Masatoshi*; Yokoya, Akinari; Fujii, Kentaro; Saito, Yuji

Chemical Physics Letters, 495(1-3), p.90 - 95, 2010/07

https://doi.org/10.1016/j.cplett.2010.06.056

The X-ray absorption of nucleotides (adenosine-5'-monophosphate, guanosine-5'-monophosophate, and cytidine-5'-monophosophate) are measured in both water solutions and thin solid films at X-ray energies near the nitrogen K-edge in the "water-window" region. Each spectrum corresponds to the selective excitation of a nucleobase site in a nucleotide, and thus has features similar to the spectrum of the corresponding nucleobase. An additional new peak in the energy region of the nitrogen 1s* resonance is observed for each nucleotide. No significant difference between the water solutions and thin solid films is found, which might be attributable to the hydrophobic properties of a nucleobase in a nucleotide.

Synchrotron radiation photoelectron studies for primary radiation effects using a liquid water jet in vacuum; Total and partial photoelectron yields for liquid water mear the oxygen -edge

Ukai, Masatoshi*; Yokoya, Akinari; Nonaka, Yusuke*; Fujii, Kentaro; Saito, Yuji

Radiation Physics and Chemistry, 78(12), p.1202 - 1206, 2009/12

https://doi.org/10.1016/j.radphyschem.2009.07.011

To substantiate the hydrated structure of DNA from the view point of the electronic properties, we developed a new spectroscopic technique of photoelectrons ejected from solutions dissolving biological molecules using soft X-ray synchrotron radiation in combination with liquid jet in vacuum. The experiments are carried out at the BL23SU in SPring-8, Japan. The liquid sample is maintained in the form of continuous micro-beam ( = 20 m) in vacuum and is intersected by a well focused nearly micro-beam of synchrotron-radiation of less than 50 m. In this paper, we present (1) the partial yields of photoelectrons for liquid water molecules and oxygen Auger electron spectra in the energy range around the oxygen K-edge, and (2) the total photoelectron yields for DNA nucleotides (AMP, CMP, and GMP) in water solutions near nitrogen K-edge, which correspond to the X-ray absorption spectra (XANES).

Corrosion behavior of steels in liquid lead-bismuth with low oxygen concentrations

Kurata, Yuji; Futakawa, Masatoshi; Saito, Shigeru

Journal of Nuclear Materials, 373(1-3), p.164 - 178, 2008/02

https://doi.org/10.1016/j.jnucmat.2007.05.051

Corrosion tests in pots were conducted to elucidate corrosion behavior of various steels in liquid lead-bismuth for 3000h under the condition of an oxygen concentration of 510wt% at 450C and an oxygen concentration of 310wt% at 550C, respectively. Significant corrosion was not observed at 450C for ferritic/martensitic steels, F82H, Mod.9Cr-1Mo steel, 410SS, 430SS except 2.25Cr-1Mo steel. Pb-Bi penetration into steels and dissolution of elements into Pb-Bi were severe at 550C even for ferritic/martensitic steels. Typical dissolution attack occurred for pure iron both at 550C without surface FeO and at 450C with a thin FeO film. Ferritization due to dissolution of Ni and Cr, and Pb-Bi penetration were recognized for austenitic stainless steels, 316SS and 14Cr-16Ni-2Mo steel at both temperatures of 450C and 550C. The phenomena were mitigated for 18Cr-20Ni-5Si steel. In some cases oxide films could not be a corrosion barrier in liquid lead-bismuth.

Development of aluminum (Al5083)-clad ternary Ag-In-Cd alloy for JSNS decoupled moderator

Teshigawara, Makoto; Harada, Masahide; Saito, Shigeru; Oikawa, Kenichi; Maekawa, Fujio; Futakawa, Masatoshi; Kikuchi, Kenji; Kato, Takashi; Ikeda, Yujiro; Naoe, Takashi*; et al.

Journal of Nuclear Materials, 356(1-3), p.300 - 307, 2006/09

https://doi.org/10.1016/j.jnucmat.2006.05.017

We adopted silver-indium-cadmium (Ag-In-Cd) alloy as a material of decoupler for decoupled moderator in JSNS. However, from the heat removal and corrosion protection points of view, the Ag-In-Cd alloy is needed to clad between Al alloys (Al5083). We attempted to obtain good bonding conditions for between Al5083 and ternary Ag-In-Cd alloys by HIPing tests. The good HIP condition was found for small test piece (20mm). Though a hardened layer due to the formation of AlAg was found in the bonding layer, the rupture strength of the bonding layer was more than 20 MPa, which was the calculated design stress. Bonding tests of a large size piece (20020030 mm), which simulated the real scale, were also performed according to the results of small size tests. The result also gave good bonding and enough required-mechanical-strength, however the rupture strength of the large size test was smaller than that of small one.