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Kobayashi, Daisuke; Yamamoto, Masahiko; Nishida, Naoki; Miyoshi, Ryuta; Nemoto, Ryo*; Hayashi, Hiroyuki*; Kato, Keisuke; Nishino, Saki; Kuno, Takehiko; Kitao, Takahiko; et al.
Nihon Hozen Gakkai Dai-18-Kai Gakujutsu Koenkai Yoshishu, p.237 - 240, 2022/07
All gloves attached to glove-box in Tokai Reprocessing Plant have a fixed expiration date and have to be replaced every 4-year. However, degrees of glove deterioration are different depending on its usage environment (frequency, chemicals, radiation, etc.), because of rubber products. Therefore, physical properties such as tensile strength, elongation, hardness of gloves are measured, and the life-time of gloves are estimated. As a result, gloves without any defects in its appearance have enough physical property for acceptance criteria of new glove. The extrapolated physical property of glove is sufficiently larger than the reported values of damaged glove. No deterioration in physical properties of gloves, that are periodically replaced without any defects in its appearance, is observed and the usable life-time of the glove is estimated to be 8 years.
Goto, Sho; Aoki, Kenji; Morimoto, Kenji; Tsuboi, Masatoshi; Isozaki, Naohiko; Furukawa, Ryuichi; Kitagawa, Osamu; Fukaya, Yasuhiro*
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.517 - 520, 2021/07
no abstracts in English
Kofu, Maiko; Hashimoto, Naoki*; Akiba, Hiroshi*; Kobayashi, Hirokazu*; Kitagawa, Hiroshi*; Iida, Kazuki*; Nakamura, Mitsutaka; Yamamuro, Osamu*
Physical Review B, 96(5), p.054304_1 - 054304_7, 2017/08
Times Cited Count：15 Percentile：58.3(Materials Science, Multidisciplinary)The vibrational states of hydrogen atoms in bulk and nanocrystalline palladium were examined in a wide energy region 
meV using neutron spectroscopy. In bulk PdH
, the vibrational excitations of H atoms were roughly reproduced by the quantum harmonic oscillator (QHO) model. In PdH
nanocrystals with a diameter of 8 nm, however, additional vibrational excitations were found at energies above 80 meV. The energies and intensities of the additional states were not explained by QHO but reasonably described as vibrations in a highly anharmonic trumpet-like potential. The additional excitations are attributed to the vibrations of H atoms at tetrahedral sites in the subsurface region stabilized by surface effects. This is an experimental work which clearly detects hydrogen vibration 
metal nanoparticles.
Kitagawa, Osamu; Suzuki, Yoshimasa; Kurosawa, Akira; Watahiki, Masaru; Hiyama, Toshiaki
JAEA-Technology 2006-031, 29 Pages, 2006/03
JAEA-Technology-2006-031.pdf:2.92MB
Using the correlation between electric conductivity and acidity in solution, we have investigated an analytical method that is able to determine acidity in the nitric acid solution by measuring electric conductivity of sample diluted with distilled water, and correcting the electric conductivity for plutonium(Pu) and uranium(U) using multivariate analysis method. We obtained good results as follows, (1) Acidity in the nitric acid solutions containing Pu and U obtained by this method was good agreement, within 10%, compared with the acidity measured by potentiometric titration method. (2) For plutonium nitrate solution and plutonium-uranium mixed nitrate solution, the repeatability and reproducibility for the measurement of electric conductivity at 25.0
C were less than 0.52%, and 1.53% respectively. (3) Impurities such as americium and iron in the solutions did not influence to the measurement of electric conductivity, if total amounts of these impurities were less than 1% compared with those of Pu and U. From the results described above, electric conductivity measuring method has been applying to analysis of acidity in the nitric acid solutions containing Pu and U at high concentration handled in Plutonium Conversion Development Facility. Furthermore, this method can be expected for the application to analysis of acidity in nitric acid solutions containing Pu and U for reprocessing process.
Surugaya, Naoki; Kitagawa, Osamu; Kurosawa, Akira; Hiyama, Toshiaki
no journal, ,
Analytical activities handling radioactive materials involve quite tedious procedures, and require highly skilled operators for obtaining reliable results with a high degree of accuracy. Therefore, analytical performance depend much on human ability. In order to maintain human resources at higher level, education and personnel training should be conducted by proper measures based on a system. At TRP, skill test in a laboratory authorization system was established for the engineers of the analytical laboratory, and has been implemented for several years. According to the levels of the required skill, the engineers are trained and educated to obtain the license in the system. Persons who desire to acquire more practical techniques or skills by carrying out on-the-job training are examined in the system. This experience has been confirmed by exercises done in the currently operating TRP. This paper presents our analytical activities and training program we have applied over recent years.
Kitagawa, Osamu; Kurosawa, Akira; Hiyama, Toshiaki
no journal, ,
no abstracts in English
Kofu, Maiko; Hashimoto, Naoki*; Akiba, Hiroshi*; Kobayashi, Hirokazu*; Kitagawa, Hiroshi*; Tyagi, M.*; Faraone, A.*; Copley, J.*; Lohstorh, W.*; Iida, Kazuki*; et al.
no journal, ,
no abstracts in English
Sugaya, Atsushi; Meguro, Yoshihiro; Kitagawa, Osamu; Aoya, Juri
no journal, ,
I will offer a presentation about update on decommissioning and radioactive waste management in Monju, Fugen and TRP at the JAEA and situation of co-operation with NDA in UK. I also give
Aoya, Juri; McCombs, H.*; Sugaya, Atsushi; Taguchi, Shigeo; Kitagawa, Osamu; Meguro, Yoshihiro; Crowther, M.*
no journal, ,
NDA and JAEA have a collaboration agreement to promote information sharing and best practice in radioactive waste management and decommissioning since 2008. NDA and JAEA have different challenges and approaches to ongoing projects. Both organizations have mutual interest in their respective technologies and experiences since cooperation would be mutual benefit to complete decommissioning and radioactive waste management safely and effectively. Within the collaboration agreement, the presenters visited NDA and JAEA sites to obtain a greater understanding and opportunities to discussion on decommissioning projects. This project aims to identify the potential collaboration areas and challenges, which could be supported by the technologies from another organization. The recommendations for future collaboration opportunities are reported with the current progress towards decommissioning across the NDA and JAEA estates.
