Deposition of gaseous radionuclides to fruit

Abstract

14 C , 35 S and 3 H are released to the environment during the operation of gas-cooled reactors and were identified as radionuclides of interest by the BIOMASS Fruits Working Group. This paper provides a review of the deposition, uptake, allocation and loss of these radionuclides with respect to fruit and conceptual models for gaseous radionuclides. It is concluded that the mechanisms for the uptake of CO 35 S , HTO and 14 CO 2 are well understood and that their deposition velocities have been quantified. There is also a reasonable body of work on the translocation of 14 C once in the crop, but much less for 35 S and 3 H , which are considered to follow source–sink relationships. The loss rates of the three radionuclides show large differences, with tritium lost rapidly in the form of HTO but retained longer when converted to OBT. The losses of 14 C are less and those of sulphur are minimal post fixation. When fruit crops alone are considered, the quantity of information is further reduced but predictions on possible behaviour of these radionuclide species can be made from the current knowledge.