Study on distribution of radioactive substances around Fukushima Dai-ichi Nuclear Power Plant, 1; Radiation monitoring and mapping of the radioactive contamination distribution

Mikami, Satoshi   ; Sato, Tetsuro; Seki, Akiyuki   ; Takemiya, Hiroshi; Matsumoto, Shinichiro; Saito, Kimiaki  

In Fukushima Prefecture and the prefectures in neighborhood, dose rate measurement by NaI(Tl) survaymeter, In situ measurement using a germanium semiconductor detector and investigation of depth distribution in soil using a scraper plate were conducted. The nuclides of Cs-137, Cs-134 and Ag-110m were detected in sufficiently many points to create a distribution maps by the in situ measurement. The values of dose rate measured by the surveymeters and the estimated ones by the in situ measurements with Ge detector showed good agreement. Averaged value of the estimated parameter was 1.17 g/cm.