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Tashiro, Shinsuke; Uchiyama, Gunzo; Ono, Takuya; Amano, Yuki; Yoshida, Ryoichiro; Abe, Hitoshi
Nuclear Technology, 208(7), p.1205 - 1213, 2022/07
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)A clogging behavior of a high-efficiency particulate air (HEPA) filter at solvent fire accidents for reprocessing facilities has been studied. In this study, the burning rates of 30% tri-butyl phosphate (TBP)/dodecane (DD) mixed solvent and DD solvent and the differential pressure (
P) of a high airflow typed HEPA filter applied in the actual facilities in Japan were measured. It was confirmed that the mainly burned was DD at the early stage of the mixed solvent burning and the TBP at the late stage. Furthermore, it was found that the P rapidly rose at the late stage of the mixed solvent burning. The increase of the release ratio of the unburned particulate composition (TBP, its degraded solvent and inorganic phosphorus (P
O
)) was considered to contribute to the rapid rise. The correlating formulas with the P and the mass of the loading particulates, except for the region of the rapid rise of P, could be induced.
Hidaka, Akihide
Proceedings of 2021 International Congress on Advances in Nuclear Power Plants (ICAPP 2021) (USB Flash Drive), 10 Pages, 2021/10
Author recently proposed that the Type A glassy Cesium-bearing microparticles that were released during the Fukushima accident may have been formed by melting and atomization of glass fibers of the High Efficiency Particulate Air (HEPA) filter in the Stand-by Gas Treatment System (SGTS) line in Unit 3 during the hydrogen explosion. In the present study, the components of the Type A and glass fibers of HEPA filter were examined using EPMA. The results showed that the components of the Type A were almost the same as that of the glass fibers except for Cs, Fe, Sn, which are considered to have been contained in the in-vessel-derived particles. When the glass fiber was irradiated with the electron beam of the Electron Probe Micro Analyzer (EPMA) under vacuum condition, spherical particles of a few micro m size were formed that looked very similar to the Type A. These strongly suggest that the HEPA filter is Si source of the Type A.
Hidaka, Akihide
Nihon Genshiryoku Gakkai-Shi ATOMO
, 63(9), p.679 - 680, 2021/09
no abstracts in English
Tsukamoto, Michio; Takada, Junichi; Koike, Tadao; Watanabe, Koji*; Miyata, Teijiro*; Nishio, Gunji*; Murata, Mikio*; Uchiyama, Gunzo
JAERI-Tech 2001-031, 47 Pages, 2001/03
JAERI-Tech-2001-031.pdf:2.75MB
no abstracts in English
Takada, Junichi; Suzuki, Motoe; Tsukamoto, Michio; Koike, Tadao; *
JAERI-Tech 96-054, 237 Pages, 1996/12
no abstracts in English
Takada, Junichi; Suzuki, Motoe; Tsukamoto, Michio; Koike, Tadao; Nishio, Gunji
JAERI-Tech 95-024, 339 Pages, 1995/03
no abstracts in English
Abe, Hitoshi; Nishio, Gunji; Naito, Yoshitaka
JAERI-M 93-220, 107 Pages, 1993/11
no abstracts in English
Nishio, Gunji; Suzuki, Motoe; Takada, Junichi; Koike, Tadao; Tsukamoto, Michio
JAERI-M 93-019, 209 Pages, 1993/02
no abstracts in English
Ikezawa, Yoshio; Matsui, Hiroshi; Yoshida, Yoshikazu*; *; *; *; *; *
Aerosols: Science,Industry,Health and Environment,Vol. 2, p.786 - 789, 1990/00
no abstracts in English
-
Solid Waste Treatment System II; *; *; ; ;
JAERI-M 82-024, 33 Pages, 1982/03
no abstracts in English
Abe, Hitoshi
no journal, ,
In PUREX fuel reprocessing process, uranium and plutonium are separated and purified from the other elements by solvent extraction which used tributyl-phosphate and dodecane. In this report, solvent fire was taken up as one of the severe accidents in the fuel reprocessing plants by referring common safety countermeasures, exhaustive selection of design base accidents in Rokkasho-plant and definition of severe accidents in Nuclear Reactor Regulation Law and present influence evaluation methods for the accident were collected and organized. Furthermore grasp of issues of the methods and solution for the issues were investigated on the basis of objective and technical viewpoint.
Hagiwara, Hiroki; Imoto, Jumpei; Hidaka, Akihide
no journal, ,
no abstracts in English
Hidaka, Akihide
no journal, ,
Estimating the formation mechanisms of insoluble radioactive cesium particles (Type A) released into the environment at the time of the Fukushima Daiichi NPS accident is useful for clarifying the accident progression. The author pointed out that the origin of Type A may be that the Unit 3 HEPA filter (glass fiber: GF) was melted and atomized during a hydrogen explosion. In that case, carbon in the activated carbon filter or GF binder is likely to be present with the Type A particles. However, in the previous observations, it has been difficult to identify carbon because carbon tape has been used for fixing particles. In this study, carbon was identified using an EPMA and a sample table other than carbon tape. As a result, the carbon content of Type A was similar to that of GF, which is considered to be of binder origin. This is consistent with the hypothesis by the author.
