None

Saikuru Kiko Giho, (16), p.198 - 202, 2009/09

https://rdreview.jaea.go.jp/gihou/pdf2/n16-26.pdf

https://rdreview.jaea.go.jp/gihou/pdf2/n16-27.pdf

None

Effect of V and Nb on precipitation behavior and mechanical properties of high Cr steel

Onizawa, Takashi; Wakai, Takashi; Ando, Masanori; Aoto, Kazumi

Nuclear Engineering and Design, 238(2), p.408 - 416, 2008/02

https://doi.org/10.1016/j.nucengdes.2006.09.013

This paper studies the long term efficiency and stability of strengthening mechanisms provided by V and Nb in high chromium ferritic steels. These elements are believed to improve the high temperature strength of high Cr steels by precipitating as carbides and/or nitrides, namely fine MX particles. However, the long term efficiency and stability of such precipitation strengthening mechanisms provided by the fine MX particles have not been clarified yet. A series of trial products controlling V and Nb contents is produced and mechanical tests are conducted to investigate the effect of these elements on the mechanical properties and the long term stability of the MX strengthening mechanism. Before and after a long term aging process, metallurgical examinations and quantitative analyses are conducted to investigate the effect of these elements on the microstructure evolutions. Based on these results, the long term efficiency and stability of the strengthening mechanisms provided by the fine MX particles are discussed.

Novel photosensitive materials for hydrogen generation through photovoltaic electricity

Yamaguchi, Kenji; Udono, Haruhiko*

International Journal of Hydrogen Energy, 32(14), p.2726 - 2729, 2007/09

https://doi.org/10.1016/j.ijhydene.2006.09.014

no abstracts in English

High energy heavy ion induced structural disorder in LiTiO

Nakazawa, Tetsuya; Naito, Akira*; Aruga, Takeo; Grismanovs, V.*; Chimi, Yasuhiro; Iwase, Akihiro*; Jitsukawa, Shiro

Journal of Nuclear Materials, 367-370(2), p.1398 - 1403, 2007/08

https://doi.org/10.1016/j.jnucmat.2007.04.003

no abstracts in English

Compatibility between Be-Ti alloys and F82H steel

Tsuchiya, Kunihiko; Kawamura, Hiroshi; Ishida, Takuya

Journal of Nuclear Materials, 367-370(2), p.1018 - 1022, 2007/08

https://doi.org/10.1016/j.jnucmat.2007.03.186

no abstracts in English

Design and modification of steam generator safety system of FBR MONJU

Matsuura, Makoto; Hatori, Masakazu; Ikeda, Makinori

Nuclear Engineering and Design, 237(12-13), p.1419 - 1428, 2007/07

https://doi.org/10.1016/j.nucengdes.2006.09.046

MONJU is a prototype Fast Breeder Reactor (FBR) in Japan. The sodium-water reaction in the steam generator (SG) is one of the important safety assessment items for a sodium cooled reactor like MONJU. A latest evaluation method on the design margin against the overheating tube rupture showed that it had not enough margins on the present SG system in the worst case. For improving that margin, it needs to shorten the time of the sodium-water reaction by earlier water leak detection in the SG and sooner water ejection from the SG tubes. Therefore MONJU is now carrying out the following modification works (1) addition of steam relief valves, (2) addition of a gas pressure gauge with changing the interlock logic and lowering the trigger level, (3) reducing the opening of the valves on the SG gas flow line to the dump tank because of earlier detection for the pressure rise. After this modification, the design margin of the SG system will be sufficiently improved. For the tube materials, the value of the cumulative damage for the creep failure will be much smaller than 1, and the equivalent stress for the ductile failure will be much smaller than the tensile strength.

RCA/IAEA third external dosimetry intercomparisons in East Asia region

Yamamoto, Hideaki; Yoshizawa, Michio; Murakami, Hiroyuki; Momose, Takumaro*; Tsujimura, Norio*; Kanai, Katsuta*; Cruz-Suarez, R.*

Radiation Protection Dosimetry, 125(1-4), p.88 - 92, 2007/07

https://doi.org/10.1093/rpd/ncl539

The purpose of this paper is to discuss the results of the third intercomparison exercise of external radiation dosimetry organized under the Regional Cooperative Agreement (RCA) in the East Asia region of the International Atomic Energy Agency (IAEA). Twenty five laboratories from 16 member states participated in the exercise. Japan Atomic Energy Research Institute (JAERI) and Japan Nuclear Cycle Development Institute (JNC) arranged the standard irradiation of the participants' dosimeters. The results of the measurements of the irradiated dosimeters for the determination of external doses were satisfactory for all participants, demonstrating good performance in their external dosimetry.

Measurement of residual stress on a unidirectional solidified AlO/YAG eutectic composite using synchrotron and neutron diffraction

Suzuki, Hiroshi; Waku, Yoshiharu*; Nakagawa, Narihito*; Akita, Koichi*; Moriai, Atsushi; Morii, Yukio

Journal of Neutron Research, 15(2), p.113 - 120, 2007/06

https://doi.org/10.1080/10238160701372471

The residual stress in only YAG phase was measured on the surface of the AlO-YAlO(YAG) eutectic composite(AlO/YAG MGC) using the low energy synchrotron X-rays. The residual stresses in plane stress condition were significantly different between top and side surfaces of the specimen. Therefore, an anisotropic triaxial residual stress probably exists within the MGC. The residual stress within the MGC was also measured using a neutron diffraction. The residual stress in the YAG phase rose from compression in the solidification direction to tension in perpendicular direction. The residual stress in the AlO phase was anisotropic compression and there was no tension in all directions. This anisotropic residual stress could be explained by the crystallographic anisotropy of thermal expansion in the AlO phase. However, both phase stresses were not balanced, so that it is expected that there would be the stress distribution in MGC sample used in this study.

Determination of I in environmental samples by AMS and NAA using an anion exchange resin disk

Suzuki, Takashi; Bamba, Shigeru*; Kitamura, Toshikatsu; Kabuto, Shoji*; Isogai, Keisuke*; Amano, Hikaru

Nuclear Instruments and Methods in Physics Research B, 259(1), p.370 - 373, 2007/06

https://doi.org/10.1016/j.nimb.2007.01.181

no abstracts in English

An Attempt for determining U/U ratio for a trace amount of uranium: Search for an extinct radionuclide Cm in the early solar system

Chai, J.; Miyamoto, Yutaka; Kokubu, Yoko; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Oura, Yasuji*; Ebihara, Mitsuru*

Journal of Radioanalytical and Nuclear Chemistry, 272(2), p.397 - 401, 2007/05

https://doi.org/10.1007/s10967-007-0535-0

Cm is an important nuclide because it has the next-shortest half-life (1.610 yr) from Pu among the transuranic nuclides. The disintegration of Cm to U by three decays and two decays and the chemical fractionation between Cm and U during the formation of solid materials in early solar system lead to changes in the ratios of U to U. This variation may provide strict constraints on the time interval between the last r-process nucleosynthetic event and the formation of the solar system. It is important to develop a practical analysis protocol to determine the isotope ratio of trace uranium in geochemical and environment samples. As uranium is the least abundant element in our solar system, analytical techniques with high sensitivity and precision are required. In this study, a double focusing inductively coupled plasma mass spectory was applied to measure isotopic ratio of uranium. By one set data obtained from the EDTA phase of the Jilin meteorite sample, the upper limit of Cm in the early solar system was calculated and Cm/U 0.003 was obtained.