JOPSS - Search Results

Journal Articles

Uncertainty and sensitivity analyses for the reduction factor of sheltering for radiation exposures

Hirouchi, Jun; Takahara, Shogo; Komagamine, Hiroshi*

Journal of Radiological Protection, 42(4), p.041503_1 - 041503_12, 2022/12

https://doi.org/10.1088/1361-6498/aca0ff

Times Cited Count：1 Percentile：31.61(Environmental Sciences)

Sheltering is one of the countermeasures against radiation exposure during nuclear accidents. The effectiveness of sheltering for inhalation exposure is often expressed by the reduction factor, which is defined as the ratio of the indoor to the outdoor cumulative radioactivity concentrations or doses. The indoor concentration is mainly controlled by the air exchange rate, penetration factor, and indoor deposition rate. Meanwhile, the air exchange rate depends on surrounding environmental conditions: the wind speed, leakage area normalized by the floor area of the house, and gross building coverage ratio. In this study, the ranges of the uncertainty of the reduction factors for particles and I $_{2}$ were investigated under various environmental conditions, and sensitivity analyses were conducted to understand the parameter with the most influence on the uncertainty of the reduction factor. From the results of the uncertainty analyses, the calculated reduction factor was highly variable depending on the environmental condition and the airtightness of the houses. The uncertainty ranges of the reduction factor for particles and I $_{2}$ were up to 0.9 and 0.3, respectively, and were smaller for newer houses. From the results of the sensitivity analyses, the wind speed was the most influential parameter on the reduction factor. Additionally, the wind speed was less influential for the reduction factor in newer houses.

Journal Articles

Penetration factor and indoor deposition rate of elementary and particulate iodine in a Japanese house for assessing the effectiveness of sheltering for radiation exposures

Hirouchi, Jun; Takahara, Shogo; Komagamine, Hiroshi*; Kato, Nobuyuki*; Matsui, Yasuto*; Yoneda, Minoru*

Journal of Radiological Protection, 41(3), p.S139 - S149, 2021/09

https://doi.org/10.1088/1361-6498/ac025b

Times Cited Count：2 Percentile：31.78(Environmental Sciences)

Sheltering is one of the countermeasures for protection against radiation exposures in nuclear accidents. The effectiveness of sheltering is often expressed by the reduction factor, that is the ratio of the indoor to the outdoor cumulative radioactivity concentrations or doses. The indoor concentration is mainly controlled by the air exchange rate, penetration factor, and indoor deposition rate. The penetration factor and indoor deposition rate depend on the surface and opening materials. We investigated experimentally these parameters of I $_{2}$ and particles. The experiment was performed in two apartment houses, three single-family houses, and chambers. The obtained penetration factor ranged 0.3 1 for particles of 0.3 1 m and 0.15 0.7 for I $_{2}$ depending on the air exchange rate. The indoor deposition rate for a house room ranged 0.007 0.2 h $^{-1}$ for particles of 0.31 m and 0.21.5 h $^{-1}$ for I $_{2}$ depending on floor materials.

Sheltering is one of the countermeasures for protection against radiation exposures in nuclear accidents. The effectiveness of sheltering is often expressed by the reduction factor, that is the ratio of the indoor to the outdoor cumulative radioactivity concentrations or doses. The indoor concentration is mainly controlled by the air exchange rate, penetration factor, and indoor deposition rate. The penetration factor and indoor deposition rate depend on the surface and opening materials. We investigated experimentally these parameters of I $_{2}$ and particles. The experiment was performed in two apartment houses, three single-family houses, and chambers. The obtained penetration factor ranged 0.3 1 for particles of 0.3 1 m and 0.1 0.6 for I $_{2}$ depending on the air exchange rate. The indoor deposition rate for a house room ranged 0.007 0.2 h $^{-1}$ for particles of 0.31 m and 0.21.5 h $^{-1}$ for I $_{2}$ depending on floor materials.

Oral presentation

Residents' Attitudes towards Shelter-in-place; The Case of Mito City, Ibaraki Prefecture

Yamaguchi, Fumie; Takahara, Shogo; Yamamoto, Kazuya; Sekiya, Naoya*

no journal, ,

no abstracts in English

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Uncertainty and sensitivity analyses for the reduction factor of sheltering for radiation exposures

Penetration factor and indoor deposition rate of elementary and particulate iodine in a Japanese house for assessing the effectiveness of sheltering for radiation exposures

Examination of the decreasing effect on internal exposure by sheltering, 2; Sensitivity analysis

Examination of the decreasing effect on internal exposure by sheltering, 1; Literature search on variation factors

Examination on radionuclide deposition distribution in house after Fukushima Dai-ichi nuclear accident

Examination of the decreasing effect on internal exposure by sheltering, 3; Investigation of penetration factor in real houses

Examination of the decreasing effect on internal exposure by sheltering, 5; Investigation of deposition rate in real houses

Examination of the decreasing effect on internal exposure by sheltering, 4; Investigation of penetration factor with a test chamber

Experimental evaluation on behavior of iodine gas

Measurement experiment of particle deposition rate and ventilation rate in houses

Examination of parameters on reduction effects of internal exposures in vehicles evacuation after nuclear accident

Penetration factor and indoor deposition rate of elementary and particulate iodine in a Japanese house for assessing the effectiveness of sheltering for radiation exposures

Residents' Attitudes towards Shelter-in-place; The Case of Mito City, Ibaraki Prefecture