Dose rate assessment in complex geometries

A code developed for calculating dose rate maps in scenarios with complex geometries and gamma radiation sources is presented in this work. It is based on the point kernel method. The code computes photon flux and dose rate in pre-selected positions due to volumetric radioactive sources in the presence of other non-emitting materials acting as shielding. Buildup factors are considered to account for radiation scattering effects, using the geometric-progression formula in the fitting function. The major advantage of this code is that there are no constraints for the generation of geometries. Any type and number of volumes can be loaded to generate the scenario by using standard 3D-CAD tools. The geometry is imported as a DXF format file. In a second step, material and radiometric attributes are imported for each volume. Volumetric radioactive sources are represented by a set of single emitting point sources distributed within its geometry. The code output has been verified in three different ways: by comparing with results from other point-kernel packages, by comparing with estimates obtained with a Monte Carlo code and by contrasting with direct experimental measurements. Results of these comparisons are presented and discussed. Finally, intrinsic limitations of the code are discussed.