Survey of radioactive contamination in Fukushima Naka-dori region, Fukushima, Japan

Due to the Fukushima Daiichi Nuclear Plant Accident, a large area of Tohoku & Kanto regions contaminated with radioactive materials. Kinki University Atomic Energy Research Institute (Kinki Univ. AERI) started researches for the radioactive contamination in Fukushima Naka-dori region from the early April 2011. As the result of the research, some conditions of the contaminations become clear. The first one is that air dose rate depends on the condition of the ground surface. The second one is that some radioisotopes from Fukushima Daiichi NPP can be easily found in Naka-dori region at April 2011, but the radioisotopes decayed and became negligible at the middle of July 2011, except for 134 Cs & 137 Cs. The last one is that the decay of radioactive Cesium at urban area of Naka-dori region is faster than the physical half-life.