Experimental studies on the deposition to crops of radioactive gases released from gas-cooled reactors — III. Carbon-14 dioxide

Experimental studies were performed under controlled environmental conditions to determine the deposition and subsequent allocation of carbon-14, following a short-term fumigation of major British crops with 14CO2. The deposition velocities varied between 0.075 and 1.32 cm3 g−1 s−1 and 0.0008 and 0.157 cm s−1 on weight and area bases, respectively. The primary sites of deposition were leaves, although other organs, e.g. ears and pods, were increasingly important as the crops developed. Activity was allocated post-deposition to those crop components actively growing at the time of deposition. The allocation was generally completed 24 h after fumigation, the exceptions to this being those crops where reproductive organs developed after the fumigation. A single exponential function was the best fit for the loss of activity from the crops. The data are discussed in the context of modelling carbon-14 contamination of crops following radioactive discharges.