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Nakanishi, Chika*; Ota, Masakazu; Hirouchi, Jun; Takahara, Shogo
JAEA-Research 2023-012, 29 Pages, 2024/02
The OSCAAR program is a probabilistic risk assessment program for reactor accidents developed by Japan Atomic Energy Agency. To improve the model included in the OSCAAR program, which is about long-term exposure caused by the resuspension of radioactive materials deposited on soil surfaces, we calculated resuspension factors for Cs-137. The one- dimensional atmosphere-SOiL-VEGetation model, SOLVEG-R was utilized to compute resuspension factor. The wind velocity was kept constant in this study since it significantly affects particle resuspension behavior. Our calculations indicate that wind velocities below 6 m s resulted in little variation in the annual mean resuspension factor at a height of 1 m. However, as wind velocities increased above 6 m s, the resuspension factor significantly increased. The resuspension factors ranged from 10 to 10 m for wind velocities ranging from 1 m s to 7 m s.
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JNC TN8440 2000-013, 179 Pages, 2000/04
The plutonium conversion development facility (PCDF) has been operated for 17 years and about 12 tons plutonium-uranium mixed oxide (MOX) powder has been converted since operation started in 1983. The first maintenance program for aging of apparatus was carried out from 1993 to 1994. The calcination-reduction fumace, liquid waste evaporator had been dismantled and renewed. The second maintenance program was carried out form 1998 to 1999. The microwave ovens, powder blender, ventilation control panel and so on were dismantled and renewed. Large volume radioactive wastes were generated during this maintenance such as the furnace, the filter casings and glove boxes. These wastes were too large to be packed into the waste container and these wastes were polluted by MOX powder unfixed on these surface. SO cutting and packing operation for these wastes and recovery of MOX powder from them were carried out. In this report, the method of this cutting and packing operation, the radioactive exposure to the operators in this operation, the estimation of nuclear material quantity migrated to filters, the evaluation of re-floating factor of radioactive material, etc. were discussed.
Ueno, Takashi; Amano, Hikaru; Kobayashi, Yoshii
Hoken Butsuri, 29(1), p.17 - 22, 1994/03
no abstracts in English
Hidaka, Akihide
no journal, ,
no abstracts in English
Abe, Tomohisa; Yoshimura, Kazuya; Sanada, Yukihisa
no journal, ,
In this study, we analyzed the variation trend of cesium concentration in the atmosphere using a data set that the Nuclear Regulation Authority regular measured the atmospheric radioactivity after the Fukushima Nuclear Plant Accident. In addition, we calculated re-suspension factor in Fukushima using the initial fallout map of cesium by the third airborne monitoring survey.
Hirouchi, Jun; Watanabe, Masatoshi*; Hayashi, Naho; Nagakubo, Azusa; Matsui, Yasuto*; Yoneda, Minoru*; Takahara, Shogo
no journal, ,
no abstracts in English
Nagakubo, Azusa; Hayashi, Naho; Matsui, Yasuto*; Hirouchi, Jun; Yoneda, Minoru*; Takahara, Shogo
no journal, ,
no abstracts in English