Safety assessment of transportation and interim storage of rice straw contaminated by radioactive cesium due to the severe accident at the Fukushima Nuclear Plant

Takeda, Seiji ; Kimura, Hideo

The rice straw contaminated by radioactive cesium was distributed to the market to feed beef cattle after the severe accident of Fukushima Nuclear Plant. It is necessary to decide the suitable method of interim storage and the guidelines of radiation control for the worker engaged for transportation and storage of contaminated straw and for the resident living near the storage place. In order to provide with their technical information, dose analyses for the scenarios on transportation and interim storage of the straw were conducted. The results of transportation scenario suggest that the worker needs the measures to decrease the dose for the dominant external exposure pathway in radioactive cesium concentration of 700,000 Bq/kg. The calculated results for interim storage scenario indicate the relation between the radioactive cesium concentration in the rice straws and the distance to suppress the dose for the resident within effective dose criterion of 1 mSv/y.