Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Togawa, Orihiko; Okura, Takehisa; Kimura, Masanori
JAEA-Review 2022-049, 76 Pages, 2023/01
JAEA-Review-2022-049.pdf:3.74MB
Before construction and after operation of nuclear facilities, environmental consequence assessments are conducted for normal operation and an emergency. These assessments mainly aim at confirming safety for the public around the facilities and producing relief for them. Environmental consequence assessments are carried out using observations/ measurements by environmental monitoring and/or model predictions by calculation models, sometimes using either of which and at other times using both them, according to the situations and necessities. First, this report investigates methods, roles, merits/demerits and relationship between observations/measurements and model predictions which are used for environmental consequence assessments of nuclear facilities, especially holding up a spent nuclear fuel reprocessing plant at Rokkasho, Aomori as an example. Next, it explains representative examples of utilization of data on observations/measurements and results on model predictions, and considers points of attention at using them. Finally, the report describes future direction, for example, improvements of observations/measurements and model predictions, and fusion of both them.
Yamaguchi, Akinori*; Yokotsuka, Muneyuki*; Furuta, Masayo*; Kubota, Kazuo*; Fujine, Sachio*; Mori, Kenji*; Yoshida, Naoki; Amano, Yuki; Abe, Hitoshi
Nihon Genshiryoku Gakkai Wabun Rombunshi (Internet), 21(4), p.173 - 182, 2022/09
Risk information obtained from probabilistic risk assessment (PRA) can be used to evaluate the effectiveness of measures against severe accidents in nuclear facilities. The PRA methods used for reprocessing facilities are considered immature compared to those for nuclear power plants, and to make the methods mature, reducing the uncertainty of accident scenarios becomes crucial. In this paper, we summarized the results of literature survey on the event progression of evaporation to dryness caused by boiling of high-level liquid waste (HLLW) which is a severe accident in reprocessing facilities and migration behavior of associated radioactive materials. Since one of the important characteristics of Ru is its tendency to form volatile compounds over the course of the event progression, the migration behavior of Ru is categorized into four stages based on temperature. Although no Ru has been released in the waste in the high temperature region, other volatile elements such as Cs could be released. Sufficient experimental data, however, have not been obtained yet. It is, therefore, necessary to further clarify the migration behavior of radioactive materials that predominantly depends on temperature in this region.
Goto, Yuichi; Inada, Satoshi; Kuno, Takehiko; Mori, Eito*
Nihon Hozen Gakkai Dai-16-Kai Gakujutsu Koenkai Yoshishu, p.221 - 224, 2019/07
Test equipment, containers, and analytical wastes, generated by experiments using spent fuel pieces in hot cell of Operation Testing Laboratory and by analysis of highly active liquid wastes in hot analytical cell line of Tokai Reprocessing Plant, are treated as highly radioactive solid wastes. These wastes are stored in specific shielded containers called waste cask and then transport to the storage facility. The treatment of these highly radioactive solid wastes have been carried out for 40 years with upgrading waste taking out system and transportation device. As a results, automation of several procedures have been achieved utilizing conventional equipment, and work efficiency and safety have been improved.
Watanabe, Koji; Tashiro, Shinsuke; Abe, Hitoshi; Takada, Junichi; Morita, Yasuji
JAERI-Tech 2004-029, 48 Pages, 2004/03
JAERI-Tech-2004-029.pdf:3.19MB
In a part of building ventilating installation of a nuclear fuel facility, a reprocessing plant for example, the pre-filters are adopted as one of the ventilation filters. In a fire accident, it is supposed that, because of the pre-filter clogging by large smoke, its differential pressure (
p) is evolved up to the value at its breakage. Therefore, in regard to maintaining the confinement of radioactive materials, it is important to predict the time course of p of the pre-filter accurately. In the current study, it was assumed that the empirical equation for the DF of the pre-filter as function of smoke particle diameter (SPD), between 0.7-2 
m, could be applied to estimating its DF for SPD above 2 m. Under this assumption, the time corresponding to its p at its breakage, calculated by CELVA-1D, was agreed well with the experimental result.
Tonoike, Kotaro; Izawa, Naoki; Okazaki, Shuji; Sugikawa, Susumu; Takeshita, Isao; *
ICNC 95: 5th Int. Conf. on Nuclear Criticality Safety,Vol. II, 0, p.10.25 - 10.32, 1995/00
no abstracts in English
Nomura, Yasushi; R.Leicht*; P.Ashton*
Journal of Nuclear Science and Technology, 31(8), p.850 - 860, 1994/08
Times Cited Count：4 Percentile：53.92(Nuclear Science & Technology)no abstracts in English
Yanagisawa, Hiroshi; Takeshita, Isao; Nomura, Masayuki; ; Tsujino, Takeshi
Proc. of the CSNI Specialist Meeting on Safety and Risk Assessment in Fuel Cycle Facilities, p.461 - 470, 1991/00
no abstracts in English
Yamashita, Masaaki; Sato, Fuminori; Horiguchi, Kenichi; Kojima, Junji; Sakai, Etsuo*; Atarashi, Daiki*; Kadota, Hirofumi*
no journal, ,
no abstracts in English
Sato, Fuminori; Horiguchi, Kenichi; Yamashita, Masaaki; Kojima, Junji
no journal, ,
no abstracts in English
