@misc{oai:repo.qst.go.jp:00064706,
 author = {Takada, Masashi and et.al and 高田 真志},
 month = {Sep},
 note = {Radioactivity was dispersed from the Fukushima Daiichi Nuclear Power Plants to the east of Japan at the Middle of March. Maps of radiation dose rates on fields were measured using helicopters. However, in public houses knowledge of dose levels is limited. People stay in houses over 16 hours longer than outdoors. We have to estimate the dose levels in houses. To evaluate exposure doses of public, dose level in a house was estimated by multiplying a factor, 0.4, with dose level outside of the house. This factor was obtained from European houses, but the houses are much different from Japanese house: construction and materials. We have to know the dose levels and shielding effects in Japanese houses for this accident.
   We measured the dose levels in several public houses and outdoors around the houses at Minami Soma city and Iitate villages in Fukushima Prefecture, using NaI(Tl) scintillation survey meters and spectrometers. Both are located at the north and north-west from the Fukushima Daiichi NPP. The dose levels around the houses ranged from 0.4 to 3 µSv/h. In the houses the dose levels are dependent on locations. At the center of house, the dose levels indicated lowest values in the houses, and an average of dose ratio between inside and outside of the houses are measured to be 0.4 and 0.55 at first and second floors, respectively. The dose levels at the first floors are 10-50% smaller than those at second floors. We are discussing smaller values at the first floors. In the rooms except the center of houses, the dose ratios are obtained to be 50-70%, larger than the center of houses. This large value may be due to small amount of radiation shield, which consists of large windows in Japanese house. Also, these larger values are being discussed. Our results could improve external exposure-dose estimation and advice decreasing dose levels in houses. 
   We are measuring radiation levels in houses and analyze experimental data. At the conference we will show you newest data., 12th International Conference on Radiation Shielding, 17th Topical Meeting of the Radiation Protection and Shielding Division of ANS},
 title = {DOSE RATE MEASUREMENTS IN PUBLIC HOUSES IN FUKUSHIMA COMPARED TO OUTSIDE},
 year = {2012}
}