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Onoe, Hironori*; Yoshida, Fumiko*; Hamamoto, Takafumi*; Saegusa, Hiromitsu*; Ishida, Keisuke*; Sawada, Atsushi
NUMO-TR-24-03, p.71 - 75, 2024/10
no abstracts in English
Onoe, Hironori*; Saegusa, Hiromitsu*; Ishida, Keisuke*; Sawada, Atsushi
NUMO-TR-24-01, p.113 - 117, 2024/05
no abstracts in English
Takubo, Yusaku*; Takayama, Yusuke; Ishida, Keisuke*; Fujisaki, Kiyoshi*
NUMO-TR-24-01, p.109 - 112, 2024/05
no abstracts in English
Koike, Ayaka*; Ishida, Keisuke*; Hamamoto, Takafumi*; Mihara, Morihiro
NUMO-TR-24-01, p.98 - 101, 2024/05
no abstracts in English
Matsukawa, Keisuke*; Satoda, Akira*; Nishida, Akemi; Guo, Z. H.*
Transactions of the 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT 27) (Internet), 10 Pages, 2024/03
no abstracts in English
Hamamoto, Takafumi*; Ishida, Keisuke*; Tachi, Yukio
NUMO-TR-22-02, p.62 - 64, 2023/03
no abstracts in English
Matsubara, Ryuta*; Ishida, Keisuke*; Mitsui, Seiichiro; Inagaki, Yaohiro*; Okubo, Takahiro*
NUMO-TR-22-02, p.65 - 67, 2023/03
no abstracts in English
Takubo, Yusaku*; Takayama, Yusuke; Ichikawa, Nozomi*; Ishida, Keisuke*; Fujisaki, Kiyoshi*
NUMO-TR-22-02, p.68 - 71, 2023/03
no abstracts in English
Koike, Ayaka*; Ishida, Keisuke*; Hamamoto, Takafumi*; Mihara, Morihiro
NUMO-TR-22-02, p.74 - 77, 2023/03
no abstracts in English
Onoe, Hironori*; Saegusa, Hiromitsu*; Ishida, Keisuke*; Fujisaki, Kiyoshi*; Sawada, Atsushi
NUMO-TR-22-02, p.78 - 80, 2023/03
no abstracts in English
Hamamoto, Takafumi*; Ishida, Keisuke*; Ishidera, Takamitsu; Tachi, Yukio
NUMO-TR-22-02, p.88 - 89, 2023/03
no abstracts in English
Hamamoto, Takafumi*; Ishida, Keisuke*; Ishidera, Takamitsu
NUMO-TR-22-02, p.58 - 61, 2023/03
no abstracts in English
Takubo, Yusaku*; Takayama, Yusuke; Idiart, A.*; Tanaka, Tatsuya*; Ishida, Keisuke*; Fujisaki, Kiyoshi*
Proceedings of 2022 International High Level Radioactive Waste Management Conference (IHLRWM 2022) (Internet), p.906 - 915, 2022/11
no abstracts in English
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.
Nishida, Akemi; Murakami, Takahiro*; Satoda, Akira*; Asano, Yuya*; Guo, Z. H.*; Oshima, Masami*; Matsukawa, Keisuke*; Nakajima, Norihiro
Transactions of the 26th International Conference on Structural Mechanics in Reactor Technology (SMiRT-26) (Internet), 10 Pages, 2022/07
no abstracts in English
Ishida, Keisuke*; Mitsui, Seiichiro
Nihon Genshiryoku Gakkai-Shi ATOMO
, 64(4), p.221 - 226, 2022/04
no abstracts in English
Furuya, Osamu*; Fujita, Satoshi*; Muta, Hitoshi*; Otori, Yasuki*; Itoi, Tatsuya*; Okamura, Shigeki*; Minagawa, Keisuke*; Nakamura, Izumi*; Fujimoto, Shigeru*; Otani, Akihito*; et al.
Proceedings of ASME 2021 Pressure Vessels and Piping Conference (PVP 2021) (Internet), 6 Pages, 2021/07
Since the Fukushima accident, with the higher safety requirements of nuclear facilities in Japan, suppliers, manufacturers and academic societies have been actively considering the reconstruction of the safety of nuclear facilities from various perspectives. The Nuclear Regulation Authority has formulated new regulatory standards and is in operation. The new regulatory standards are based on defense in depth, and have significantly raised the levels of natural hazards and have requested to strengthen the countermeasures from the perspective of preventing the simultaneous loss of safety functions due to common factors. Facilities for dealing with specific serious accidents are required to have robustness to ensure functions against earthquakes that exceed the design standards to a certain extent. In addition, since the probabilistic risk assessment (PRA) and the safety margin evaluation are performed to include the range beyond the design assumption in the safety improvement evaluation, it is very important to extent the special knowledge in the strength of important equipment for seismic safety. This paper summarizes the research and examination results of specialized knowledge on the concept of maintaining the functions of important seismic facilities and the damage index to be considered by severe earthquakes. In the other paper, the study on reliability of seismic capacity analysis for important equipment in nuclear facilities will be reported.
Nishida, Akemi; Murakami, Takahiro*; Satoda, Akira*; Asano, Yuya*; Guo, Z.*; Matsukawa, Keisuke*; Oshima, Masami*; Nakajima, Norihiro
Transactions of the 25th International Conference on Structural Mechanics in Reactor Technology (SMiRT-25) (USB Flash Drive), 10 Pages, 2019/08
Exhaustive studies on external events that may pose a threat to the structures of nuclear facilities and evaluations of the structural integrities are critical to safety. One of the components that greatly influence the behavior of the plant structure is the connection of structural members. In particular, the modeling of the connections has relied on empirical methods, and been conservatively designed and evaluated by considering them as pinned or rigid connections. Therefore, in this research, we have aimed to develop a connection modeling method that reproduces more realistic behavior by utilizing a three-dimensional model of the connection. As the first step of this research, we planned to determine the stiffness of the connections of steel structural members. The results confirmed that the connection can be regarded as a partially-restrained connection depending on the connection specifications of the structure, and the prospects for realistic stiffness evaluation of the connection were determined.
Hamamoto, Takafumi*; Ishida, Keisuke*; Shibutani, Sanae*; Fujisaki, Kiyoshi*; Tachi, Yukio; Ishiguro, Katsuhiko*; McKinley, I. G.*
Proceedings of 2019 International High-Level Radioactive Waste Management Conference (IHLRWM 2019) (USB Flash Drive), p.77 - 82, 2019/04
Hamamoto, Takafumi*; Shibutani, Sanae*; Ishida, Keisuke*; Fujisaki, Kiyoshi*; Yamada, Motoyuki*; Tachi, Yukio
Proceedings of 6th East Asia Forum on Radwaste Management Conference (EAFORM 2017) (Internet), 6 Pages, 2017/12
NUMO has developed a generic safety case to demonstrate the feasibility and safety of geological disposal of HLW and TRU in Japan and to provide a basic structure for the safety case which will be applicable to any potential site. In this safety case, the safety assessment was carried out for the repositories tailored to site descriptive models developed for three representative rock groups (plutonic, Neogene sedimentary and Pre-Neogene sedimentary rocks). Radionuclide migration parameters in rocks, i.e. distribution coefficients (Kds) and effective diffusion coefficients (Des), were derived to allow safety analysis for a range of scenarios. In this generic stage, the values of these parameter were given as the statistical values derived from laboratory data for certain rock types. The data were extracted from the latest database, with interpretation based on radionuclide speciation derived from relevant groundwater thermodynamic modelings.
