Monte Carlo modelling for the in vivo lung monitoring of enriched uranium: Results of an international comparison

► We perform well-defined in vivo calibration measurements of enriched uranium in lungs. ► A voxel model of the phantom and other needed data are provided to participants. ► Participants perform Monte Carlo simulation of the counting efficiencies. ► For about half of the participants the agreement with experiment is within ±5%. ► Other participants needed support to obtain this agreement.