Development of remote controlled type field-emission type scanning electron microscope

Yasuda, Ryo; Nishino, Yasuharu; Mita, Naoaki; Nakata, Masahito; Harada, Katsuya; Nozawa, Yukio; Amano, Hidetoshi

JAERI-Tech 2002-081, 34 Pages, 2002/10

JAERI-Tech-2002-081.pdf:11.76MB

Information about the fuel behavior under high burn-up operation is needed to assess the safety of the high burn-up fuels. Microstructures in irradiated fuel pellets and Zircaloy tubes influence on their integrity. The fundamental information about microstructures is necessary to estimate the formation mechanism and change in the properties of the fuels.The Field Emission type Scanning Electron Microscope (FE-SEM) has been hence installed at the Reactor Fuel Examination Facility (RFEF). FE-SEM is designed for the remote handling type to use high radioactive materials and has equipments to keep safety for operators. Charctarization tests were carried out using Zircaloy cladding tubes with oxide films and hydrides to confirm machine performance. In the results of the tests, high-resolution images with a magnification of 30,000 were obtained. Those results show that the apparatus is maintained high performance as well as standard type.

Development and application of PIE apparatuses for high-burnup LWR fuels

; Mita, Naoaki; Nishino, Yasuharu; Amano, Hidetoshi

JAERI-Conf 99-009, p.103 - 111, 1999/09

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-99-009.pdf

no abstracts in English

Advanced coatings for HTGR fuel particles against corrosion of SiC layer

Minato, Kazuo; Fukuda, Kosaku; Ishikawa, Akiyoshi; Mita, Naoaki

Journal of Nuclear Materials, 246(2-3), p.215 - 222, 1997/00

https://doi.org/10.1016/S0022-3115(97)00107-4

no abstracts in English

Post-irradiation destructive examinations of inert matrix nitride fuels

Matsui, Hiroki; Iwai, Takashi; Honda, Junichi; Hatakeyama, Yuichi; Mita, Naoaki; Arai, Yasuo

no journal, , 

no abstracts in English

Cs Adsorption behavior evaluation on the surface of nuclear reactor structure materials under high temperature and high pressure steam

Sumita, Takehiro*; Yonekawa, Kazuo*; Sekio, Yoshihiro; Sato, Isamu*; Kobayashi, Yoshinao*; Osaka, Masahiko; Maeda, Koji; Akasaka, Naoaki

no journal, , 

During Fukushima Daiichi Nuclear Power Plant (1F) accident, high radionuclides such as Cs and I were mainly released as fission products (FPs) due to fuel melting in units 1 to 3, and it increased radiation dose in reactor buildings. With the aim of 1F decommissioning, it is necessary to establish methods to retrieve fuel and an adequate access route, which requires knowledge of Cs adsorption behavior on the surface of structural materials during Severe Accidents (SA). However, there are no Cs adsorption behavior evaluations under the simulated SA condition with high pressure in the previous studies. In this study, CsI adsorption behavior on SUS304L under the condition was evaluated using newly designed apparatus which can control temperature, pressure, moisture and gas atmosphere. The findings from microstructural observation and elemental analysis after the adsorption test suggested that the adsorption of CsI was influenced by especially pressure.