Environmental radioactivity monitoring at Kakuma campus of Kanazawa University after the accident of Fukushima nuclear power plant

The Nuclear power plant accident at Fukushima caused by the earthquake and tsunami disaster in March, 2011 led the public to fear the considerable-range contamination with radioactivity. For the reason, we started environmental monitoring on radioactivity just outside of the RI facility in the Kakuma campus of Kanazawa Univ. A high-volume dust sampler (SHIBATA, HV-1000) was used to collect air dust onto a filter and rain water was collected in a plastic container placed on the rooftop of the facility as well. The samples were assayed by gamma-ray spectrometer with germanium detectors to obtain the concentrations of I-131, Cs-134, and Cs-137. The data were compared with those measured in the other areas in Japan to discuss how the activities diffused and migrated from the plant to many places in Japan. The peaking dates of the activities coincided with those by a trajectory calculation of air from Fukushima. The trend was confirmed for the other data in other areas. (author)