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Kokubun, Yuji; Hosomi, Kenji; Nagaoka, Mika; Seya, Natsumi; Inoue, Kazumi; Koike, Yuko; Uchiyama, Rei; Sasaki, Kazuki; Maehara, Yushi; Matsuo, Kazuki; et al.
JAEA-Review 2024-054, 168 Pages, 2025/03
JAEA-Review-2024-054.pdf:2.73MB
The Nuclear Fuel Cycle Engineering Laboratories conducts environmental radiation monitoring around the reprocessing plant in accordance with the "Safety Regulations for Reprocessing Plant of JAEA, Part IV: Environmental Monitoring". This report summarizes the results of environmental radiation monitoring conducted during the period from April 2023 to March 2024 and the results of dose calculations for the surrounding public due to the release of radioactive materials from the plant into the atmosphere and ocean. In the results of the above environmental radiation monitoring, several items were affected by radioactive materials emitted from the accident at the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company, Incorporated (changed to Tokyo Electric Power Holdings, Inc. on April 1, 2016), which occurred in March 2011. In addition, environmental monitoring plan, analysis and measurement methods, monitoring data and their chronological change, meteorological data after statistical processing, status of radioactive waste release and evaluation results of the data over the normal range are included as appendices.
Nakano, Masanao; Fujii, Tomoko; Nagaoka, Mika; Inoue, Kazumi; Koike, Yuko; Yamada, Ryohei; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; Kikuchi, Masaaki*; et al.
JAEA-Review 2019-045, 120 Pages, 2020/03
JAEA-Review-2019-045.pdf:2.54MB
Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2018. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.
Ozawa, Kazumi; Tanigawa, Hiroyasu; Morisada, Yoshiaki*; Fujii, Hidetoshi*
Fusion Engineering and Design, 98-99, p.2054 - 2057, 2015/10
Times Cited Count：1 Percentile：8.39(Nuclear Science & Technology)Reduced activation ferritic/martensitic steel, as typified by F82H, is a promising candidate for structural material of DEMO fusion reactors. To prevent plasma sputtering, tungsten (W) coating was essentially required. This study aims to examine the irradiation effects on hardness and microstructure of vacuum-plasma-spray coated W-F82H steel, with a special emphasis on the impacts of grain-refining induced by frictional stir processing (FSP). It was revealed that the hardness of the VPS-FSP W after ion-irradiation to 5.4 dpa at 800
C were not remarkably changed, where bulk W usually exhibited significant irradiation hardening.
Tanigawa, Hiroyasu; Ozawa, Kazumi; Morisada, Yoshiaki*; Noh, S.*; Fujii, Hidetoshi*
Fusion Engineering and Design, 98-99, p.2080 - 2084, 2015/10
Times Cited Count：15 Percentile：72.27(Nuclear Science & Technology)The vacuum plasma spray (VPS) technique has been investigated as the most practical method to form Tungsten (W) layer as a plasma facing material in fusion devices. The issues are the thermal conductivity and the strength of VPS-W, i.e., the thermal conductivity of VPS-W were significantly lower than that of the bulk W, and the hardness of VPS-W is much less than that of the bulk W. These are mainly caused by the porous structure of VPS-W. In order to solve these issues, friction stir processing (FPS) was applied on VPS-W in this study. It was suggested that FSP can contribute to significant improvement both in mechanical and thermal properties of VPS-W coating.
Nakagawa, Kazumichi*; Kaneko, Fusae*; Ota, Yoshimi*; Tanaka, Masahito*; Kitada, Tomo*; Agui, Akane; Fujii, Kentaro; Yokoya, Akinari; Watanabe, Kazutoshi*; Yamada, Toru*
Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.271 - 273, 2005/06
Times Cited Count：13 Percentile：51.32(Spectroscopy)no abstracts in English
Kaneko, Fusae*; Tanaka, Masahito*; Narita, Satoru*; Kitada, Tomo*; Matsui, Takahiro*; Nakagawa, Kazumichi*; Agui, Akane; Fujii, Kentaro; Yokoya, Akinari
Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.291 - 294, 2005/06
Times Cited Count：19 Percentile：63.35(Spectroscopy)no abstracts in English
Tanaka, Masahito*; Nakagawa, Kazumichi*; Agui, Akane; Fujii, Kentaro; Yokoya, Akinari
Physica Scripta, T115, p.873 - 876, 2005/00
no abstracts in English
Konomura, Mamoru; Ogawa, Takashi; Okano, Yasushi; Yamaguchi, Hiroyuki; Murakami, Tsutomu; Takaki, Naoyuki; Nishiguchi, Youhei; Sugino, Kazuteru; Naganuma, Masayuki; Hishida, Masahiko; et al.
JNC TN9400 2004-035, 2071 Pages, 2004/06
JNC-TN9400-2004-035.pdf:76.42MB
The attractive concepts for Sodium-, lead-bismuth-, helium- and water-cooled FBRs have been created through using typical plant features and employing advanced technologies. Efforts on evaluating technological prospects of feasibility have been paid for these concepts. Also, it was comfirmed if these concepts satisfy design requierments of capability and performance presumed in the feasibilty study on commertialization of Fast Breeder Reactor Systems. As results, it was concluded that the selection of sodium-cooled reactor was most rational for practical use of FBR technologies in 2015.
Suzuki, Satoru; Fujishima, Atsushi; Ueno, Kenichi; Ichikawa, Yasuaki*; Kawamura, Katsuyuki*; Fujii, Naoki*; Shibata, Masahiro; Sato, Haruo; Kitayama, Kazumi*
Nendo Kagaku, 41(2), p.43 - 57, 2001/12
None
Kaneko, Tetsuji*; Tanaka, Norihiko*; Kawaharada, Yoshiyuki*; Fujii, Kazumi*; Iwanami, Masaru*; Ishioka, Shinichi*; Yokoyama, Yutaka*; Umehara, Ryuji*; Kato, Chiaki; Ueno, Fumiyoshi; et al.
no journal, ,
no abstracts in English
-ray irradiation on inhibition of steel corrosion in diluted sea waterSato, Tomonori; Kato, Chiaki; Motooka, Takafumi; Ueno, Fumiyoshi; Nakano, Junichi; Kaneko, Tetsuji*; Tanaka, Norihiko*; Kawaharada, Yoshiyuki*; Fujii, Kazumi*; Iwanami, Masaru*; et al.
no journal, ,
no abstracts in English
Yokoyama, Yutaka*; Umehara, Ryuji*; Tanaka, Norihiko*; Kawaharada, Yoshiyuki*; Kaneko, Tetsuji*; Fujii, Kazumi*; Iwanami, Masaru*; Ishioka, Shinichi*; Kato, Chiaki; Ueno, Fumiyoshi; et al.
no journal, ,
no abstracts in English
Hamaguchi, Dai; Tanigawa, Hiroyasu; Ozawa, Kazumi; Fujii, Hidetoshi*; Morisada, Yoshiaki*
no journal, ,
Friction-Stir Process were applied to OFCCu in order to evaluate the applicability of the process to mechanically strengthening pure-Cu and possible structural improvement on CuCrZr alloy. In this study, the tool rotational speed was varied from 50 to 500 rpm in order to clarify the effect of rotational speed on the process. The result showed the achievement of very fine grain structure at the rotational speed of 100 and 200 rpm and also the hardness increase to about 1.5 time higher within the stir-zone than that of the base metal at the most. However, the result also revealed that the rapid decrease of the hardness toward a depth direction and relatively shallow stir-zone depth compared to a length of the pin. This can be explained as post-annealing effect due to a good thermal conductivity of a pure-Cu. To avoid the effect, we are considering to introduce compulsory cooling system during the process, which application is more important to a CuCrZr alloy because more rapid cooling and lower thermal diffusion to base metal are required.
Wakai, Eiichi; Takada, Fumiki; Takaya, Shigeru; Kato, Shoichi; Kitazawa, Sin-iti; Okubo, Nariaki; Suzudo, Tomoaki; Fujii, Kimio; Yoshitake, Tsunemitsu; Kaji, Yoshiyuki; et al.
no journal, ,
no abstracts in English
Tanigawa, Hiroyasu; Ozawa, Kazumi; Morisada, Yoshiaki*; Fujii, Hidetoshi*; Noh, S.*
no journal, ,
no abstracts in English
Ozawa, Kazumi; Tanigawa, Hiroyasu; Morisada, Yoshiaki*; Fujii, Hidetoshi*
no journal, ,
no abstracts in English
Mills, R.*; Fujii, Kazumichi*; Jassey, V.*; Heffernan, L.*; Koarashi, Jun; Mattiasen, C.*; Robroek, B.*; Buttler, A.*
no journal, ,
Currently, estimates of soil carbon stock and turnover in northern forest soils ignore, to a large extent, the variability of understory plant communities, and their contribution to the within-system heterogeneity that might occur. To explore how understory plant communities may explain soil carbon stock and turnover, we analysed podsol O-horizons for organic matter characteristics and microbial communities and functions across contrasting cover of functional groups in a nemo-boreal pine forest in southern Sweden. We found plant community cover and biomass to be a poor predictor of organic matter content and quality, and of the microbial community composition to be poorly related to both. The results imply a disconnection between plant community composition and longer-term soil carbon stores in complex systems on an ecosystem scale.
Hamaguchi, Dai; Morisada, Yoshiaki*; Fujii, Hidetoshi*; Tanigawa, Hiroyasu; Ozawa, Kazumi
no journal, ,
Friction-Stir Process (FSP) were applied to OFCCu and ITER-Gr CuCrZr cooling pipe in order to evaluate the applicability of the process to mechanically strengthening pure-Cu and possible structural improvement on CuCrZr alloy. Former study revealed that the achievement of very fine grain structure at certain rotational speed and also the hardness increase to about 1.5 time higher within the stir-zone but also relatively shallow stir-zone depth compared to a length of the pin and rapid void formations. In order to avoid this phenomenon, compulsory cooling with liquid Co
during the process was introduced, and the results showed the absence of void formation at relatively lower rational speed of around 300 RPM and also maintaining the effective stir-zone to relatively higher rotational speed compared to non-cooling tests. Similar FSP tests with compulsory cooling were also applied to ITER-Gr CuCrZr cooling pipe for divertor application. The detail will be reported on the presentation.
Kaneko, Tetsuji*; Tanaka, Norihiko*; Kawaharada, Yoshiyuki*; Fujii, Kazumi*; Iwanami, Masaru*; Ishioka, Shinichi*; Yokoyama, Yutaka*; Umehara, Ryuji*; Kato, Chiaki; Ueno, Fumiyoshi; et al.
no journal, ,
no abstracts in English
Fujii, Kazumi*; Iwanami, Masaru*; Ishioka, Shinichi*; Kaneko, Tetsuji*; Tanaka, Norihiko*; Kawaharada, Yoshiyuki*; Yokoyama, Yutaka*; Umehara, Ryuji*; Kato, Chiaki; Ueno, Fumiyoshi; et al.
no journal, ,
no abstracts in English
