Applicability and reliability of the 'observed ratio' model as a means of describing the strontium and the cesium transfer from soil to plant

The report examines the suitability of the observed ratio, (OR), model as a means of describing the soil-to-plant transfer of cesium and strontium, and the reliability of results determined by this model. Literature studies have been made and are reported in order to show the discrimination between Sr and Ca, or Cs and K, respectively, and in order to show the magnitude of the OR value and the range of values it may cover. For the evaluation of results, care has been taken that only the physiologically relevant constituents of Sr, Ca, Cs, and K concentrations in the soil are taken into account, which are the water-soluble and the adsorptively bound forms. Non-mobile forms cannot be taken up by the plant and therefore are not considered in the model. In accordance with the literature reviewed, the report also differentiates between two experimental approaches: (1) hydroponics, and (2) greenhouse or field experiments. (orig./DG)