Transfer of C discharged from Tokai reprocessing plant into rice plant; Monitoring data and a simple modeling approach

Koarashi, Jun   ; Fujita, Hiroki; Onuma, Toshimitsu*; Mikami, Satoshi   ; Akiyama, Kiyomitsu; Takeishi, Minoru 

Carbon-14 is one of the most important radionuclides from the perspective of dose estimation due to the nuclear fuel cycle. Japan Atomic Energy Agency (JAEA) has conducted the careful monitoring of C in airborne release from Tokai reprocessing plant (TRP), atmospheric CO and rice grains around TRP. This report reviewed the C monitoring data obtained over ten years from 1991 to 2001. A simple mathematical model for transfer of TRP-derived C into rice plant was tested using the data set. The model-calculated C concentrations in atmospheric CO and rice grain agreed well with the observations, suggesting an applicability of the simple modeling approach to environmental assessment for atmospheric C discharge under steady-state conditions.