Rapid measurement of air dose rate surrounding roads in Fukushima evacuation zone by vehicle-borne survey with different height mounted detectors

Takeyasu, Masanori ; Takeishi, Minoru ; Yoda, Tomoyuki; Saegusa, Jun; Koizumi, Jin*; Tanabe, Tsutomu

The measurement of air dose rate surrounding roads is important for developing plans for reducing radiation exposure with road traffic. The measurements were performed by vehicle-borne or man-borne surveys until now. However, air dose rate resulting from radioactivity on roads in mainly measured for former survey, and much man-power for long time measurement was necessary for the latter. In this study, we focused on the field of view for measurement being different with a difference of the detector setting height above the ground, and carried out the vehicle-borne survey along roads in evacuation zone in Fukushima prefecture with two detectors mounted at different heights. By this measurement, air dose rate surrounding the roads is discriminated. From the results, the radioactivity contamination trend was clarified, and are valuable for developing decontamination plan around the road.