Experimental determination and geochemical modelling of retardation behaviour of radionuclides

This project of the Federal Office for Radiation Protection was coordinated by G.E.O.S.. The aim of the project was to use large-volume column experiments (diameter: 30 cm, height: 50 cm) and soils recognized by the German Federal Environment Agency for application in test procedures according to the German Federal Soil Protection Act/Ordinance to determine the most realistic KD values possible for the 9 radionuclides relevant to final disposal: Ni-63, Se-79, I-129, Cs-135, Ra-226, Np-237, Am-241, U-238 and Pu-239. The scenarios of rising groundwater due to capillary suction stress and irrigation were considered. A special GoldSimTM transport model was developed to simulate these tests, to which PHREEQC was coupled.


  • Coordination and conceptual specifications of the overall project
  • Development of a GoldSimTM simulation model for the coupled simulation of transport in the saturated and partially saturated zone, including geochemical interactions by coupling PHREEQC
  • Carrying out probabilistic sensitivity analyses on the influence of different soil parameters on the KD value
  • Model calibration and predictions for modified soil parameters