Resumen
Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste forms in the Hungarian NPP Paks. The program is designed to be used as a tool for performing the calculations necessary to analyse leach test data, a modelling program to determine if diffusion is the operating leaching mechanism (and, if not, to indicate other possible mechanisms), and a means to make extrapolations using the diffusion models. The ILT15 program contains four mathematical models that can be used to represent the data, diffusion through a semi-infinite medium, diffusion through a finite cylinder, diffusion plus partitioning of the source term and solubility limited leaching. The program is written in C++ in the Borland C++ Builder programming environment. A detailed description of application of this modelling computer program is given.