Evaluation of radiation exposure due to radioactive releases into the biosphere from a salt dome repository

Potential health consequences of hypothetical releases from a salt dome repository planned in the Federal Republic of Germany have been evaluated taking into account the following parameters: (a) contamination of near-surface groundwater by transport of radionuclides with groundwater movement from the salt dome, (b) irrigation of agricultural areas and radionuclide uptake by plants, (c) intake of activity by man through food contaminated by use of water for irrigation, through drinking water and fish consumption, and (d) internal exposure for members of the population. For quantitative assessment of long-lived radionuclide concentrations in food crops a time-dependent irrigation model was developed and used in this project. It takes into account agricultural practices used in the northern part of the Federal Republic of Germany. For the important long-lived nuclides potential, individual doses were calculated for members of the local population. The uncertainties of this approach are discussed with reference to 237Np. Conditions of agricultural production in the far future are a more uncertain factor than the variability of the biological parameters considered. It is doubtful whether, in general, the accuracy of such calculations can permit any quantitative mathematical procedure for the optimization of radiation protection measures in waste disposal options. (author)