1-D modelling of radionuclide migration through permeable and fractured rock for arbitrary length decay chains using numerical inversion of Laplace transforms

Abstract This paper presents analytical solutions to Laplace-transformed radionuclide transport equations for arbitrary length decay chains in permeable and fractured rock. These can be combined to give approximate expressions for transport through heterogeneous media consisting of an arbitrary number of porous and/or fractured rock units. The time-dependent solutions are obtained by numerical inversion using Talbot's algorithm. This has been found to be a very efficient, accurate and flexible technique.