Complementary studies: biosphere modelling for dose assessments of radioactive waste repositories

Already as a result of the highly successful first phase of the international BIOsphere MOdel Validation Study (BIOMOVS) considerable progress had been made in representing features, events and processes (FEPs) relevant to many aspects of biosphere modelling. Nevertheless, at the start of BIOMOVS II, it was recognised that there was a need to further investigate and develop available tools for representing the biosphere in long-term assessments of radioactive waste disposal. At a practical level, the Complementary Studies working group looked at the way contemporary models were able to perform calculations for a real site given the type of data available in real performance assessments. The use of a well-defined database allowed detailed comparisons of FEPs for trans-port as well as for the calculation of exposure pathways. Results have indicated not only the common basis in many model descriptions but also where further development and consolidation are required. This paper summarises some of the key findings from the study. The title Complementary Studies was chosen for the working group to indicate that work would complement waste disposal related scenarios from the first phase of BIOMOVS. Within BIOMOVS II the work of the group also complemented the Reference Biospheres working group.