The main innovative features of a new model developed for plutonium dose assessments are presented. The physiological assumptions and the improvement of model predictions for plutonium activity in biological samples are discussed. Preliminary results relating to dose calculations and sensitivity analysis are also presented. The model has been applied to a well documented case of contamination. This was the first opportunity to test the new features of the model in a practical case and to show how to apply sensitivity techniques to a complex data set of a contamination case.