부산대학교 도서관

In this study, soil samples were collected at Canadian embassy in Tokyo (about 300 km from Fukushima) on 23 March and 23 May of 2011 for purposes of estimating concentrations of radionuclides in fallout, the total fallout inventory, the depth distribution of radionuclide of interest and the elevated ambient gamma dose-rate at this limited location. Some fission products and actinides were analyzed using gamma-ray spectrometry, alpha spectrometry and liquid scintillation counting. The elevated activity concentration levels of I, I,Cs,Cs,Cs, Te, mTe, Te, Ba and La were measured by the gamma-ray spectrometer in the first sample collected on 23 March. Two months after the accident, theCs andCs became only detectable nuclides. A mass relaxation depth of 3.0 g/cm was determined by the activities on the depth distribution ofCs in a soil core. The total fallout inventory was thus calculated as 225 kBq/m on March sampling date and 25 kBq/m on May sampling date. The ambient gamma dose-rates in the sampling area estimated by the fallout fission products inventory andCs depth distribution ranged from 184 to 38 nGy/h. There was no detectable americium or plutonium in the soil samples by alpha spectrometry. Although Sr or Sr were detected supposedly as a result of this accident, it was less than the detection limit, which was about 0.4 Bq/kg in the soil samples. [ABSTRACT FROM AUTHOR]